Yellowstone rivers

Yellowstone rivers

Unraveling the controls on channel form and geomorphic history in northern Yellowstone National Park, Wyoming

Overview: We will analyze the controls on fluvial processes and determine the geomorphic history of two streams in northern Yellowstone National Park. Documentation and analysis of the geomorphic history of streams in northern Yellowstone is essential for understanding how a trophic cascade caused by the removal and reintroduction of wolves may have altered stream behavior in the 20th century. To assess stream behavior during the historical period, it is necessary to quantify baseline natural stream variability during the Holocene. Along Blacktail Dear Creek, we will map terrace/floodplain landforms and measure channel geometry. The timing of sedimentation on terraces and floodplains will be studied using radiocarbon dating and short-lived radionuclides. On the Gallatin River, we will survey channel cross sections throughout the drainage basin to investigate hydraulic geometry and environmental controls on channel form.

Figure 1: Streams in the Northern Range provide key riparian habitat in the relatively dry lower elevations of Yellowstone National Park.

When: July 22 – August 24, 2019

Where: We will meet in Walla Walla, WA. From Walla Walla, we drive to Yellowstone National Park and spend three weeks performing field work. We will return to Walla Walla for 1 week of work in the lab. From Walla Walla, students will return to their home institutions.

Who: A team of 4 students and Dr. Lyman Persico, Whitman College ([email protected])

Prerequisites and Recommended Courses: A course in earth surface processes (geomorphology) and sedimentology will be most useful. Other useful courses include paleoclimatology, ecology, and any field-based classes. What is most important, however, is a passion for working out of doors and a willingness to tackle unpredictable problems that always present themselves while doing field work. Applicants should have an interest in interdisciplinary research at the intersection of geology and ecology. Applicants must be willing to spend long days collecting field data in one of the most beautiful places on Earth, and spend the evenings discussing fluvial geomorphology and camping. Students wanting to use this work for a senior thesis will have preference. Letters of reference should speak to the applicant’s ability to work independently and their potential for both field and laboratory research.

Expectations and Obligations:
1. Participation in all project-related work during the summer (July 22-Aug 24).
2. Data analyses at home institution and regular conference calls with the research team throughout the academic year.
3. Write an abstract and present a poster at the Rocky Mountain sectional meeting of the Geological Society of America in Utah Valley, UT (May 4-5 2020).
4. Expected but not required: Use the research for a senior thesis (or equivalent).

PROJECT DESCRIPTION

Introduction and Rationale
Riparian corridors are key ecological zones in semiarid regions, as they provide abundant water and food resources and are typically more biologically diverse than the overall landscape. These corridors are particularly important in the relatively dry Northern Range of Yellowstone National Park (Yellowstone National Park, 1997). The Northern Range is synonymous with the winter range of the northern Yellowstone Elk herd. The Northern Range (Fig. 1 and 2) is relatively dry (mean annual precipitation: 350-500 mm) and the low-elevation region is dominated by sagebrush-grasslands with scattered conifer groves. In the early 20th century, many streams in the Northern Range hosted abundant beaver and beaver dams (Warren, 1926). Beaver are considered a keystone species of riverine-riparian ecosystems (Naiman et al., 1988b) as beaver dams elevate water tables, expand riparian habitat, increase aquatic productivity, and store more groundwater (Naiman et al., 1986; Naiman et al., 1988a; Pollock et al., 1995; Gurnell, 1998; Anderson et al., 2006; Westbrook et al., 2006; Gribb, 2007; Cooke and Zack, 2008; Brzyski and Schulte, 2009; Green and Westbrook, 2009). Beaver dams also reduce stream velocity and induce sedimentation in channels and on floodplains (Butler and Malanson, 1995). It has been hypothesized that the long-term effect of beaver damming may substantially aggrade valley floors (Ruedemann and Schoonmaker, 1938; Ives, 1942). More recent research using radiocarbon dating, however, has shown that there are limits on the net aggradation of beaver damming to less than 3 meters (Persico and Meyer, 2009; Polvi and Wohl, 2012; Persico and Meyer, 2013).

Figure 2: Blacktail Deer Creek and the Gallatin River drain portions of the Washburn and Gallatin ranges, respectively. The proposed study will focus on lower elevation stream reaches that receive less snow and are considered elk winter range.

Figure 3: The Northern Range stream of Elk Creek contained many beaver dams in the 1920s that extended across much of the valley floor. Those beaver dams were abandoned by the 1920s and the stream has incised over 2 m from the top of the beaver bond sediments.

Interestingly, beaver have been largely absent from the Northern Range since the mid-20th century (Fig. 3, Jonas, 1955). The causes of beaver decline and associated riparian zone changes have been debated in both the scientific literature and popular press over the past three decades (Yellowstone National Park, 1997; National Research Council, 2002). It has been proposed that Northern Range streams experienced an ecosystem state switch from beaver-willow to elk-grasslands during the latter half of the 20th century (Wolf et al., 2007). According to some, the loss of beaver is the direct result of competition from elk (Chadde and Kay, 1991). Elk populations increased dramatically in the 20th century due to the extirpation of wolves by hunting. Large elk populations have led to over-browsing of willow and other riparian vegetation. Mature aspen and riparian tall-willow stands, important food resources for beaver, have declined since park establishment, but aspen were never abundant in historic or Holocene time (Houston, 1982; Whitlock and Bartlein, 1993; Romme et al., 1995).

The loss of beaver and elk browsing have potentially caused significant alterations to Northern Range streams. The loss of beaver dams have caused channels to incise and floodplain abandonment (Fig. 3, Wolf et al., 2007; Beschta and Ripple, 2018). Channel incision has also caused the lowering of water tables, which limits willow and aspen growth (Marshall et al., 2013). These changes serve to disconnect channels from floodplains thereby reducing riparian areas (Marshall et al., 2013), however preliminary results indicate that at least some stream incision in the Northern Range predates the historical period (Fig. 5, Persico and Meyer, 2009). Additionally, the decreased riparian vegetation has led to widespread degradation of stream and riparian habitat via channel widening by bank erosion (Chadde and Kay, 1991; Beschta and Ripple, 2006; Wolf et al., 2007).

Regardless of changes to vegetation structure in Northern Range riparian communities, there are other factors that control channel form and stream dynamics including flow properties, bank material, subsurface conditions, and climatic variability (Knighton, 1998). In the greater Yellowstone ecosystem, climate variability is a significant factor in the long-term history of channel dynamics (Meyer, 2001; Persico and Meyer, 2009, 2013). Channel response to forest-fire related sedimentation is another important control on channel morphology in YNP (Meyer et al., 1992; Meyer et al., 1995; Legleiter et al., 2003). Although there is abundant research on the ecological dynamics of the Northern Range, relatively little research has focused on the stream channel and valley floor itself (Fig. 4). For example, there is little research that has attempted to differentiate terrace and floodplain deposits using geochronologic methods. Both Blacktail Deer Creek and the Gallatin River are sites where there is much discussion of the impacts of trophic cascades on channel dynamics (Beschta and Ripple, 2006; Beschta and Ripple, 2018). The proposed research is an important contribution to the study of the magnitude and extent of the effects of trophic cascades, which has even made it to the popular press in recent years (Robbins, 2005; Chadwick, 2010).

Figure 4: Blacktail Deer Creek drains the northern flanks of the Washburn Range. The stream has an inset floodplain. It is not clear how much of the valley floor is a Holocene terrace or historical floodplain that has been more recently abandoned.

Figure 5: On the east fork of Blacktail Deer Creek a sediments in a terrace ~1.5 above the modern floodplain accumulated 7-3 ka and incision commenced ~1.5 ka (Persico and Meyer, 2009). It is unknown how widespread this surface is or its relationship to the historical floodplain proposed by Bescthta and Ripple (2018).

Proposed Research: The primary goal of this project is to determine the environmental controls on channel form and fluvial dynamics on two streams in northern Yellowstone. This work will expand on the previous research on channel forms in Yellowstone (e.g. Meyer et al., 1995; Meyer, 2001; Legleiter et al., 2003; Persico and Meyer, 2009) and focus on detailed measurements of valley floor and channel morphology. The primary goal will be accomplished through mapping of terrace/floodplain surfaces, characterizing terrace/floodplain deposits, and estimation of the timing of floodplain/terrace aggradation.

On Blacktail Deer Creek, we will combine high-resolution RTK GPS measurements with geomorphic mapping to produce surficial geologic maps of terrace and floodplain surfaces (Fig. 4). On Blacktail Deer Creek glacial erosion and modification of topography has resulted in diverse fluvial valley widths and gradients, so that very gentle to steep channels exist across the entire range of contributing basin areas. Thus, the relationship between hydrologic and geomorphic controls and channel morphology can be fully examined. The stratigraphy and soil development in terrace deposits will be described in detail. Sediment samples will be collected from the sediments for laboratory analyses of grain size and organic content. Charcoal and wood fragments will be collected for 14C dating. The youngest ages of organic material that can be dated using 14C is 1950 due to above ground nuclear testing that has “spiked” the amount of 14C in the atmosphere since that time. Additionally, significant variability of atmospheric14C in the past 100-200 years has created a radiocarbon plateau, which produces significant errors when calibrating these young ages (Fig. 7). We will supplement the timing of sediment deposition via14C with short-lived radionuclides (Goldberg and Koide, 1962; Krishnaswami et al., 1980). We will collect sediment samples and estimate concentrations of atmospherically-derived 137CS and 210Pb in both terrace and floodplain sediments. These analyses allow for a more detailed analysis of sedimentation rates in the past several hundred years (Whiting et al., 2005; Soster et al., 2007).

On the Gallatin River, the goal of the proposed research is to characterize downstream changes to the geometry of the active channel. The Gallatin River drains the western flank of the Gallatin Range. The upper reaches of the river are outside of elk winter range providing a control for streams in northern Yellowstone that have not been influenced by elk overbrowsing. A series of cross sections will be measured by RTK GPS and supplemented by a total station when necessary. The geometry of channels will be combined with surficial and geologic maps to determine geologic controls on channel forms, which can be compared to environmental controls such as elk browsing. In the lab, cross sections will be used to estimate the hydraulics of floods along the river using HEC-RAS modeling.

Potential Student Projects
Project 1: Mapping of channel, floodplain, and terrace landforms along Blacktail Deer Creek. This student project will use a combination of survey data and surficial geologic mapping to produce a highly detailed map of fluvial landforms along the valley floor. Features will be mapped with <0.25m vertical precision using both an RTK GPS and total station. Coring analysis of up to 18 trees located on terrace surfaces will help to constrain the age of the floodplain and terrace surfaces. In the lab the student will use ARCGIS to analyze the magnitude of incision and percentage of the valley floor that is comprised of the different surfaces.

Project 2: Characterization of floodplain/terrace sediments and estimation of the timing of deposition by radiocarbon dating. This student project will focus on the deposit of terraces and floodplains. Field activities will include recording detailed stratigraphic and soil horizon observations and sampling the sediments and organic material preserved in the sediments (Fig 6). Estimation of the timing of deposition of terrace surfaces will be made by dating charcoal and wood preserved in overbank deposits. Laboratory activities at Whitman College will include using the laser diffractometer to measure sediment sizes, identifying wood type, and preparing samples of modern root samples to send to Direct AMS for14C analyses. I will work with the student and the home advisor for analysis of the ages in including calibration.

Project 3: Characterization of floodplain/terrace sediments and estimation of the timing of deposition by short-lived radionuclides. This student project will focus on the same terrace and floodplain stratigraphy of Project 2. The use of the short-lived radionuclides 147Cs and 210Pb will be used to determine terrace and floodplain stability. Field activities include recording detailed stratigraphic and soil horizon observations and sampling the sediments and organic material preserved in the sediments. Sediment samples will be collected from locations where multiple terrace and floodplain surfaces are present. Short cores will be collected using a push corer. Laboratory activities at Whitman College will consist of measuring the organic content of sediments using Loss on Ignition (LOI) and processing the cores by subsampling each core at 5 cm intervals. These sub samples will be sent to Oberlin College for determination of 210Pb and147Cs concentrations. The student will work with me, and Amanda Schmidt at Oberlin on analyzing the isotope data.

Project 4: Measuring downstream changes in hydraulic geometry of the Gallatin River. This student project will focus on characterizing the hydraulic geometry of the Gallatin River. Field activities will include collecting a series of cross sections in and above elk winter range. This student project will analyze a series of cross sections. Laboratory activities include developing a simple 2D hydraulic model using HEC-RAS. This model will allow the student to assess where there has been recent incision of the channel.

Figure 6: Terrace deposit on Blacktail Deer Creek with abundant woody material for 14C dating. The stratigraphy and soil development will be described in the field. Samples will be collected for 14C, organic content, and grain size analyses.

Figure 7: Calibration age of a hypothetical 14C age of 150 years. Due to a radiocarbon plateau, this simple has high probability of any time in the past 300 years.

PROJECT LOGISTICS

Students will arrive in Walla Walla on July 22. We will spend two nights on Whitman Campus. We will prepare for the field work in the science building on July 23 and leave for Yellowstone on July 24. While in Yellowstone we will first stay north of the Park, near Gardiner, MT. We will likely camp at the Eagle Creek campground, although, the campground is first-come-first-serve, so the backup plan is to stay at the Jardine campground, which is more remote and not as likely to fill up. We will stay at Eagle Creek for 14 nights while performing all field work on Blacktail Dear Creek. Most meals will be prepared at the campsite on camp stoves borrowed from the Whitman College. We will resupply and do laundry in the town of Gardiner. For field work on the Gallatin River we will most likely stay at the Rainbow Point campground on Hebgen Lake.

Students will need to be able to carry a medium-sized field pack and field equipment every day. We will also pack water and lunch each day. We will be hiking up to six miles per day. Most of the hiking will be on the valley floor, thus relatively low gradients. We will also be surveying stream cross sections. This will require multiple river crossings.

Research Schedule:

Phase 1 (7/22-7/25) Travel and Introduction

  • Arrive in Walla Walla
  • Crash course in methods of fluvial geomorphology
  • Risk assessment and mitigation discussion
  • Pack
  • Travel to Yellowstone

Phase 2 (7/26-8/9) Blacktail Deer Plateau Field Work

  • Mapping and survey of terrace and floodplain surfaces
  • Terrace deposit stratigraphic descriptions and sampling for radiocarbon
  • Sediment Core sampling for short-lived radionuclides

Phase 3 (8/10-8/19) Gallatin River Field Work and Travel

  • Mapping and survey of terrace and floodplain surfaces
  • Drive to Walla Walla

Phase 4 (8/20-8/24) Laboratory Analyses

  • Prepare and ship wood/charcoal samples for radiocarbon analyses
  • Prepare and ship sediment samples for short-lived radionuclide analyses
  • Begin analyses of cross section and mapping data

Phase 5 (4-5 May 2020) Professional Development

  • Poster presentations at Rocky Mountain GSA

Safety:
There are risks inherent to field research. These risks include physical injuries such as broken bones and sprained ankles. Other risks include venomous snakes, dehydration, heat stroke, sunburn, and mosquito bites. These risks will be mitigated by following proper field and wilderness protocols. Professor Persico has extensive field and wilderness experience as a field camp instructor and outdoor recreation trip leader. Professor Persico will hold a safety meeting in Walla Walla to explain the risks and the strategies that will be employed to mitigate these risks. Another risk in Yellowstone are bears. Professor Persico has 10 seasons of field experience with Yellowstone bears. Bear spray is the standard bear deterrent in YNP. We will be working mostly at low elevations, where black bears are more common (Grizzly bears claim the higher elevations farther away from humans during the summer). Black bears are less of a hazard compared to Grizzly Bears (much less aggressive). Professor Persico will talk about bear safety before the field work. This will include watching a You Tube video of the proper procedure for using bear spray. Each member of the team will have a can of bear spray. Additionally, while in the field I will use the time-honored tradition of banging one’s shovel against rocks when hiking.

PROFESSIONAL DEVELOPMENT

Professor Persico will take all participants to the Rocky Mountain section meeting of the Geological Society of America in Utah Valley, Utah (4-5 May 2020). Each student will prepare their own first-authored abstract with the other students as collaborators.
All students are required to complete a 4-6 page paper (short contribution) that will be published in the Proceedings of the Keck Geology Consortium 2019 Volume (see examples from previous years). The first draft of this paper will be reviewed by your research advisor at your home institution sometime in late February, 2019, with the revised version sent to the project directors by March 1. Final versions of your paper and figures will be submitted to the Keck Office in Mid-March.

References

Anderson, C.B., Griffith, C.R., Rosemond, A.D., Rozzi, R., Dollenz, O., 2006. The effects of invasive North American beavers on riparian plant communities in Cape Horn, Chile – Do exotic beavers engineer differently in sub-Antarctic ecosystems? Biological Conservation 128, 467-474.

Beschta, R.L., Ripple, W.J., 2006. River channel dynamics following extirpation of wolves in northwestern Yellowstone National Park, USA. Earth Surface Processes and Landforms 31, 1525-1539.

Beschta, R.L., Ripple, W.J., 2018. Can large carnivores change streams via a trophic cascade? Ecohydrology 0, e2048.

Brzyski, J.R., Schulte, B.A., 2009. Beaver (Castor canadensis) Impacts on Herbaceous and Woody Vegetation in Southeastern Georgia. American Midland Naturalist 162, 74-86.

Butler, D.R., Malanson, G.P., 1995. Sedimentation rates and patterns in beaver ponds in a mountain environment. Geomorpholo 13, 255-269.

Chadde, S.W., Kay, C.E., 1991. Tall-willow communities on Yellowstone’s Northern Range: A test of the “natural-regulation” paradigm, in: Keiter, R.B., Boyce, M.S. (Eds.), The Greater Yellowstone Ecosystem. Yale University Press, Binghamton, pp. 231-263.

Chadwick, D.H., 2010. Wolf Wars, National Geographic.

Cooke, H.A., Zack, S., 2008. Influence of beaver dam density on riparian areas and riparian birds in shrubsteppe of Wyoming. Western North American Naturalist 68, 365-373.

Goldberg, E.D., Koide, M., 1962. Geochronological studies of deep sea sediments by the ionium/thorium method. Goeochemica Cosmochemica Acta 26, 417-450.

Green, K.C., Westbrook, C.J., 2009. Changes in riparian area structure, channel hydraulics, and sediment yield following loss of beaver dams. Journal of Ecosystems and Management 10, 68-79.

Gribb, W., 2007. Beaver (Castor canadensis) impacts and characteristics on stream hydrology and vegetation in the Snake River Drainage System, Grand Teton National Park, Wyoming. United States Department of the Interior, Report on file, National Park Service, Moose WY.

Gurnell, A., 1998. The hydrogeomorphological effects of beaver dam-building activity. Prog. Phys. Geogr. 22, 167-189.

Houston, D.B., 1982. The northern Yellowstone elk. Macmillian, New York, NY.

Ives, R., 1942. The beaver-meadow complex. Journal of Geomorphology 5, 191-203.

Jonas, R.J., 1955. A population and ecological study of the beaver (Castor canadensis) of Yellowstone National Park. University of Idaho, p. 193.

Knighton, D., 1998. Fluvial Forms and Processes A New Perspective. Oxford University Press, New York.

Krishnaswami, S., Benninger, L.K., Aller, R.C., Von, Damm, K.L., 1980. Atmospherically derived radionuclides as tracers of sediment mixing and accumulation in near-shore marine and lake sediments—Evidence from 7Be, 210Pb, and 239,240Pu. Earth and Planetary Science Letters 47, 307–318.

Legleiter, C., Lawrence, R., Fonstad, M., Marcus, W., Aspinall, R., 2003. Fluvial response a decade after wildfire in the northern Yellowstone ecosystem: a spatially explicit analysis. Geomorpholo 54, 119-136.

Marshall, K.N., Hobbs, N.T., Cooper, D.J., 2013. Stream hydrology limits recovery of riparian ecosystems after wolf reintroduction. Proceedings of the Royal Society B-Biological Sciences 280.

Meyer, G.A., 2001. Recent large-magnitude floods and their impact on valley-floor environments of northeastern Yellowstone. Geomorpholo 40, 271-290.

Meyer, G.A., Wells, S.G., Balling, R.C., Jull, A.J.T., 1992. Response of alluvial systems to fire and climate change in Yellowstone-National-Park. Nature 357, 147.

Meyer, G.A., Wells, S.G., Jull, A.J.T., 1995. Fire and alluvial chronology in Yellowstone National Park: Climatic and intrinsic controls on Holocene geomorphic processes. Geological Society of America Bulletin 107, 1211-1230.

Naiman, R.J., Johnston, C.A., Kelley, J.C., 1988a. Alteration of North-American streams by beaver. Bioscience 38, 753-762.

Naiman, R.J., Johnston, C.A., Kelly, J.C., 1988b. Alteration of North American streams by beaver. Bioscience 38, 753-762.

Naiman, R.J., Melillo, J.M., Hobbie, J.E., 1986. Ecosystem alteration of boreal forest streams by beaver (Castor-canadensis). Ecology 67, 1254-1269.

National Research Council, 2002. Ecological Dynamics on Yellowstone’s Northern Range. National Academy Press, Washington DC.

Persico, L., Meyer, G., 2009. Holocene beaver damming, fluvial geomorphology, and climate in Yellowstone National Park, Wyoming. Quaternary Res 71, 340-353.

Persico, L., Meyer, G., 2013. Natural and historical variability in fluvial processes, beaver activity, and climate in the Greater Yellowstone Ecosystem. Earth Surface Processes and Landforms 38, 728-750.

Pollock, M.M., Naiman, R.J., Erickson, C.A., Johnston, C.A., Paster, J., Pinay, G., 1995. Beaver as engineers: influences of biotic and abiotic characteristics of drainage basins, in: Jones, C.G., Lawton, J.H. (Eds.), Linking species and ecosystems. Chapman and Hall, New York, pp. 117-126.

Polvi, L.E., Wohl, E., 2012. The beaver meadow complex revisited – the role of beavers in post-glacial floodplain development. Earth Surface Processes and Landforms 37, 332-346.

Robbins, J., 2005. Hunting Habits of Wolves Change Ecological Balance in Yellowstone, New York Times, New York, NY.

Romme, W.H., Turner, M.G., Wallace, L.L., Walker, J.S., 1995. Aspen, elk, and fire in northern Yellowstone National Park. Ecology 76, 2097-2106.

Ruedemann, R., Schoonmaker, W., 1938. Beaver-dams as geologic agents. Science 88, 523-525.

Soster, F.M., Matisoff, G., Whiting, P.J., Fornes, W., Ketterer, M., 2007. Floodplain sedimentation rates in an alpine watershed determined by radionuclide techniques. Earth surface processes and landforms 32, 2038-2051.

Warren, E.R., 1926. A study of the beaver in the Yancey region of Yellowstone National Park. Roosevelt Wildlife Annals 1, Syracuse.

Westbrook, C.J., Cooper, D.J., Baker, B.W., 2006. Beaver dams and overbank floods influence groundwater-surface water interactions of a Rocky Mountain riparian area. Water Resources Research 42, 2005WR004560.

Whiting, P.J., Matisoff, G., Fornes, W., 2005. Suspended sediment sources and transport distances in the Yellowstone River basin. Geological Society of America Bulletin 117, 515-529.

Whitlock, C., Bartlein, P.J., 1993. Spatial variations of Holocene climatic change in the Yellowstone region. Quaternary Res 39, 231-238.

Wolf, E.C., Cooper, D.J., Hobbs, N.T., 2007. Hydrologic regime and herbivory stabilize an alternative state in Yellowstone National Park. Ecological Applications 17, 1572-1587.

Yellowstone National Park, 1997. Yellowstone’s Northern Range: Complexity and Change in a Wildland Ecosystem. National Park Service, Mammoth Hot Springs.

Wisconsin springs

Wisconsin springs

Thermal imaging to characterize the spatial distribution of temperature in freshwater springs

Overview: During the Wisconsin Springs Gateway project, we will explore how local variations in topography, surficial geology, and bedrock geology influence the spatial distribution of temperature in freshwater springs. Cold and stable temperatures are often cited as important environmental conditions in springs, affecting species richness and diversity (Gaffield et al., 2005; Knight and Notestein, 2008; von Fumetti et al., 2017). However, there is currently a lack of information on the spatial distribution of temperature in springs and how distributions vary among springs of differing types. Using an infrared camera that is suspended above a spring pool, there are opportunities to examine the thermal properties of springs in a relatively quick and noninvasive manner. Our primary goal is to collect detailed temperature data sets from springs in a variety of geologic settings across Wisconsin. In the process, students will use thermal imaging infrared cameras and Trimble Juno® handheld data collectors, as well as learn a variety of flow gaging techniques and water sampling methods.

A spring emerging from fractured limestone in southwestern Wisconsin

When: July 1 – August 2, 2019

Where: Beloit, Wisconsin (introduction and lab work) and field sites across Wisconsin (field work).

Who: Three rising sophomores, one rising senior, and project leader Dr. Sue Swanson (Beloit College, [email protected])

Prerequisites and Recommended Courses: There are no specific coursework prerequisites for the three rising sophomores, but the project is ideally suited for students with interests in hydrogeology, fluvial geomorphology, water chemistry, and aquatic ecology.

The rising senior should have completed two or more of the following courses: hydrogeology, geomorphology, sedimentology, geochemistry, geographic information systems. The student will also serve as a peer mentor, so they should have prior experience as a teaching assistant or tutor.

All students applying for this project should enjoy being outside and walking through streams and wetlands in boots or waders (will be provided). We will also work in forested environments. All of these environments tend to have biting insects, such as mosquitos or ticks. Individuals should be open to using insect repellent and should be capable of carrying field equipment over uneven ground.

Expectations and Obligations:
All students
• Participation in all project-related work during the summer (July 1 – August 2, 2019).
• Commitment to work collaboratively in an environment of mutual respect.
Rising sophomores
• Write a team abstract and present a poster at the American Water Resources Association – Wisconsin Section annual meeting in spring 2020 (all expenses covered).
Rising senior
• Follow up data analysis at home institution and regular conference call with project director throughout academic year.
• Write an abstract and present a poster at the American Water Resources Association – Wisconsin Section annual meeting in spring 2020 (all expenses covered).
• Write a short contribution (4-6 pages text + figures) to be published in the Proceedings of the Keck Geology Consortium 2020 Volume (first draft due Mid-February).
• Expected but not required: Use this work for the completion of a senior thesis (or equivalent) at your home institution.

PROJECT DESCRIPTION

Thermal imaging holds potential for characterizing the spatial distribution of temperature in freshwater springs. Cold and stable temperatures are often cited as important environmental conditions in springs, affecting species richness and diversity (Gaffield et al., 2005; Knight and Notestein, 2008, von Fumetti et al., 2017). However, there is currently a lack of information on the spatial distribution of temperatures in springs and how distributions vary among springs of differing types, such as seepage/filtration springs or fracture springs (Figures 1 and 2). Using an infrared camera that is suspended above a spring pool, there are opportunities to examine the temperature distribution of springs in a relatively quick and noninvasive manner. Ground-based thermal imaging has been shown to differentiate between diffuse and focused groundwater discharge (Cardenas et al., 2008; Deitchman and Loheide, 2009) and initial testing of the use of a hand-held thermal camera to characterize springs of differing types in Wisconsin shows a distinction between seepage/filtration springs and fracture springs. Seepage/filtration springs display a right-skewed or bimodal distribution and higher standard deviation in temperature, whereas fracture springs display a bell-curve distribution and lower standard deviation (Kopas and Swanson, 2016).

Figure 1: Example of a seepage/filtration rheocrene spring.

Figure 2: Example of a fracture rheocrene spring.

The recently completed inventory of springs in Wisconsin mapped and characterized 415 large springs, or springs discharging approximately 0.25 cfs or more at the time of surveying (Figure 3) (Swanson et al., in review). Using this database, our primary goal will be to collect detailed temperature data sets from spring sites across Wisconsin. We will measure the temperature distribution within spring pools at a minimum of 20 rheocrenes (springs discharging to streams) selected from the Wisconsin springs inventory, ten with seepage/filtration morphologies and ten with fracture morphologies. Imagery will be collected in mid-July, when differences in spring pool and groundwater temperatures are at a maximum.

To complement the thermal data and further characterize spring pool characteristics that can influence aquatic habitat, field water quality indicators such as pH, specific conductance, and dissolved oxygen (DO), will also be measured and mapped across each spring pool. Following the characterization of the spatial distribution of temperature and each water quality indicator for each spring type, we will compare summary statistics, such as variance or skewness, to the spring flux (ft/s), defined as spring flow (ft3/s) divided by spring orifice area (ft2), for each spring. Spring flux provides a meaningful way to distinguish between groundwater discharge features dominated by discrete versus diffuse groundwater flow. The median fluxes for fracture or contact springs, seepage-filtration springs, and ponds in Wisconsin are 4x10-2 ft/s, 6x10-3 ft/s, and 1x10-5 ft/s, respectively (Swanson et al., in review). Robust relationships between temperature or other water quality summary statistics and spring flux, which is more easily measured, would then allow the use of spring flux as a predictor of the spatial distribution of temperature and water quality in springs of differing types.

Figure 3: Distribution and types of springs in Wisconsin (Swanson et al., in review).

Potential Student Projects: Students will work as a team throughout the project to organize and calibrate field equipment, image the distribution of spring pool temperatures, and measure and map water quality within the spring pools. After returning to campus, the three rising sophomores will work collaboratively on the thermal data set, while the rising senior (and peer mentor) will primarily work on the geochemical data set.

1. Thermal characterization of spring pools of differing spring types. The three rising sophomores will work together on the statistical analysis of the temperature data. This will involve downloading and organizing the thermal data from all of the field sites (>20), tabulating the thermal data and calculating summary statistics, and performing basic statistical tests, such an F-test of equality of variances. If there is time, we may also use spatial statistics (Moran’s I) to describe the degree to which temperature values similar in magnitude are clustered within spring pools of differing spring types.

2. Geochemical characterization of spring pools of differing spring types. The rising senior (and peer mentor) will take the lead on the statistical and spatial analysis of the water chemistry data. Similar to the temperature data, this will involve downloading and organizing the pH, conductivity, and DO data for all of the field sites (>20), tabulating data, calculating summary statistics, and performing basic statistical tests. However, because water quality data will be collected as point data, they must be processed before performing spatial statistics. During the following academic year, the rising senior will create isopleth maps of the spring pool parameters (using ArcGIS) and perform the subsequent spatial statistics as part of their senior thesis research.

PROJECT LOGISTICS

Students will arrive in Beloit, Wisconsin on July 1. The first week will be spent in the classrooms and laboratories at Beloit College, where students will be introduced to the project through a series of lectures, discussions, and local field excursions to springs within 1-2 hours driving distance. We will also discuss field safety and strategies for effective communication in the field, practice field methods, and gather equipment for field work. During this time, students will be housed on campus in Beloit College dorm rooms that are dedicated to the students for the entire 5-week program. The next two-and-a-half weeks will be spent mostly in the field, although we will return to Beloit on weekends. While in the field, the group will camp. All camping gear (tents, cooking gear) will be provided. Gear such as sleeping bags, sleeping pads, knee boots, and waders will be available for loan. The final week-and-a-half will include data analysis and preparation of our abstract and poster. Students depart Beloit on August 2.

PROFESSIONAL DEVELOPMENT

Conducting a research project at an early career stage is not only a résumé-builder, but helps to develop many skills that are applicable after the summer is over. Working and living together in the field, collaboratively completing a project from start to finish, and starting to develop a network of friends and colleagues all build resiliency, capabilities, and cognitive abilities. This Gateway Keck project offers these experiences in a supportive yet challenging environment. Students will work on real scientific questions, using standard and state-of-the art field and lab equipment; they will also receive training in science communication, including informal interactions with the public in the field, and more formal methods of presenting information such as lightning talks and giving better, more engaging research presentations.

References

Cardenas, M.B., Harvey, J.W., Packman, A.I., and Scott, D.T. (2008) Ground-based thermography of fluvial systems at low and high discharge reveals potential complex thermal heterogeneity driven by flow variation and bioroughness: Hydrological Processes, Vol. 22, doi: 10.1002/hyp.6932.

Deitchman, R.S., and Loheide II, S.P. (2009) Ground-based thermal imaging of groundwater flow processes at the seepage face, Geophysical Research Letters, Vol. 36, doi: 10.1029/2009GL038103.

Gaffield, S.J., Potter, K.W., and Wang, L. (2005) Predicting the summer temperature of small streams in southwestern Wisconsin: Journal of the American Water Resources Union, Vol. 41, doi: 10.1111/j.1752-1688.2005.tb03714.x.

Knight, R.L., Notestein, S.K. (2008) Springs as Ecosystems, in Summary and Synthesis of the Available Literature on the Effects of Nutrients on Spring Organisms and Systems: University of Florida Water Institute, p.1-46.

Kopas, D.C. and Swanson, S.K. (2016) The Application of Handheld Infrared Thermography in the Characterization of Springs in Southern Wisconsin, Geological Society of America Abstracts with Programs, Vol. 48, No. 7, Abstract 78-1.

Loheide, S.P., II and Gorelick, S.M. (2006) Quantifying stream-aquifer interactions through analysis of remotely sensed thermographic profiles and in-situ temperature histories: Environmental Science and Technology, Vol. 40, No. 10, p. 3336–3341.

Swanson, S.K., Graham, G.G., Hart, D.J. (in review) An inventory of springs in Wisconsin, WGNHS Bulletin.

Von Fumetti, S., Bieri-Wigger, F., and Nagel, P., 2017, Temperature variability and its influence on macroinvertebrate assemblages of alpine springs: Ecohydrology, Vol. 10, Issue 7, doi: 10.1002/eco.1878.

Montana dinosaurs

Montana dinosaurs

Exploring Late Cretaceous Wetland Ecosystems: Dinosaurs and Vertebrate Microfossils in Montana

Overview: Eight students will focus on collecting and interpreting the fossils of backboned animals found in the classic Cretaceous geological record of Montana with an aim of exploring diversity before the mass extinction event that wiped out the dinosaurs. The work will focus on fossils from the Judith River and Hell Creek formations. These formations preserve abundant vertebrate microfossil bonebeds (VMBs), which are concentrated deposits of mostly small bones and teeth from diverse organisms that inhabited ancient swamps and lakes (from tiny fish to giant dinosaurs, and everything in between). Students will work with collections housed at Macalester College and will conduct field and museum-based research in Montana, where they will discover, describe, and sample VMBs. Our work will yield novel insights into coastal plain ecosystems during the final stages of the Late Cretaceous, and will provide new data on a time of significant global change culminating in mass extinction (the K-Pg event).

Students in the field, Upper Missouri River Breaks National Monument

When: June 10 – July 12, 2019 (tentative)

Where: St. Paul/Minneapolis, Minnesota (introduction & lab work), Fort Peck Reservoir (Hell Creek Formation, Montana, field work); Upper Missouri River Breaks National Monument (Judith River Formation, field work), and Museum of the Rockies, Bozeman, Montana (museum research).

Who: Eight students and project leaders Dr. Raymond Rogers (Macalester College, [email protected]), and Dr. Kristi Curry Rogers (Macalester College, [email protected])

Prerequisites and Recommended Courses: Because this experience is for students early in their academic careers there are no specific coursework prerequisites. We are seeking students who are interested in many or all of the following: using field and laboratory methods to explore scientific questions about the ancient Earth, discovering and identifying fossils, understanding how fossils get preserved (taphonomy), using analytical tools to ask questions about organismal paleobiology (bone histology). Students should be comfortable sharing close quarters in tents (including in cold and rainy weather), camping at “primitive campsites” without running water or toilets, canoeing and swimming, hiking several miles in a day, and being without cell phone coverage for up to a week. Students will need to maintain composure in field conditions that are safe but that may include bad weather, difficult trail and boat conditions, and wildlife. Support in the form of field gear loans will be provided to students who do not own their own. All tents and cooking gear will be provided.

Expectations and Obligations:
1. Participation in all project-related work during the summer (approximately June 10-July 12, 2019)
2. Write abstract with team members and present a paper (poster or talk) at the Geological Society of America National Meeting in Phoenix, Arizona September 22-25, 2019 (all expenses covered).

PROJECT DESCRIPTION

This project builds on longstanding research in the Upper Cretaceous, dinosaur-bearing rock record of Montana focused on Vertebrate Microfossil Bonebeds (VMBs) – accumulations of the resilient hard parts (bones and teeth) of ancient organisms (Figure 1). The teeth, scales, and bones preserved in VMBs provide details on the ecology of ancient ecosystems. Our work will include an investigation of fossil collections housed at Macalester College, the Science Museum of Minnesota, and the Museum of the Rockies, and an exploration of the remote Montana landscapes of the Fort Peck Reservoir and Upper Missouri River Breaks National Monument (UMRBNM) in search of new fossil localities (Figure 2).

Figure 1: Carnivorous theropod dinosaur tooth within a vertebrate microfossil bonebed.

VMBs are fairly common in Mesozoic and Cenozoic terrestrial records, where they have been studied to recover the fossils of rare small-bodied organisms. They also serve as an important archive of relative abundance and species richness in ancient vertebrate communities (e.g., Brinkman et al. 2004, 2007; Demar & Breithaupt 2006; Sankey & Baszio 2008). Our Keck project will investigate the taphonomy and paleoecology of a select set of VMBs from classic localities within the Campanian Judith River and Maastrichtian Hell Creek Formation of north-central Montana (e.g., Rogers 1995, 1998; Rogers and Kidwell, 2000; Wilson 2008; Rogers and Brady 2010; Rogers et al. 2016, 2017, 2018). Students participating in this project will compare these classic VMB records from sedimentological, taphonomic, and paleoecological perspectives and work together to determine whether they represent similar formative histories or traveled unique pathways to the fossil record. Students will study VMB collections already housed at Macalester College, the Science Museum of Minnesota, and at the Museum of the Rockies, and they will travel to Montana where they will discover, describe, and sample VMBs in the field. Their efforts to compare and contrast VMBs in these distinctive formations will (1) advance our understanding of how VMBs form, (2) yield novel insights into the composition and structure of coastal plain paleocommunities during the final stages of the Late Cretaceous, and (3) provide new data on a time of significant global change culminating in mass extinction (the K-Pg event).

In addition, students will gain experience in:
1. Describing and interpreting common sedimentary rocks.
2. Identifying vertebrate and invertebrate fossils.
3. Sampling protocols for collecting rocks and fossils in the field.
4. Employing analytical laboratory methods (e.g., scanning electron microscopy, microscopic X-ray Fluorescence, bone histology) to answer questions.
5. Conducting the essential aspects of field work (e.g., maintaining a field notebook, utilizing topographic maps, prospecting, measuring stratigraphic section).
6. Learning to be an effective team member in the field and lab.
7. Producing and disseminating scientific information, especially to professional colleagues through presentation at the Geological Society of America meeting (September 2019).

Figure 2: Exploring Cretaceous exposures in search of fossil localities in the Upper Missouri River Breaks National Monument.

Potential Student Projects: We envision projects centered around VMB taphonomy, fossil identification, and paleohistology. At the outset, students will work as a team to sieve, recover, and identify vertebrate and invertebrate fossils from bulk matrix of the Judith and Hell Creek formations in storage at Macalester College. After some time spent on focused fossil recovery and identification, students will work in pairs to describe and interpret their fossil collections. Specific projects may include:

• Taxonomic characterization of fossil collections. Students with interests in paleoecology and evolution will explore the biodiversity of ancient lakes from the Campanian Judith River Formation and the Maastrichtian Hell Creek Formation. They will tabulate and compare faunal lists (presence/absence and relative abundance) and ultimately reconstruct and compare faunal diversity in Late Cretaceous freshwater ecosystems.

• Histological characterization of fossil collections. Students with interests in paleobiology and paleoecology will study bone histology of known ectotherms (crocodiles, turtles) and endotherms (dinosaurs, birds, mammals). Patterns of bone histology will be described and interpreted in the context of both taxonomy, animal physiology, and potential resource limitations in ancient Cretaceous ecosystems.

• Taphonomic characterization of fossil collections I. Students with interests in fossil preservation and taphonomy will compare bone modification features across formations, including breakage patterns, evidence rounding and abrasion, and tooth marks (and potentially other evidence of feeding/digestion).

• Taphonomic characterization of fossil collections II. Students with interests in fossil preservation and taphonomy will document in detail the size and shape of fossil bones and teeth collected from the Judith River, Two Medicine, and Hell Creek Formations. An automated image analysis approach will be used to capture size data and statistical approaches will be used to test whether the size and/or shape of fossils varies among sites and between formations.

Figure 3: Canoeing in the Upper Missouri River Breaks National Monument.

PROJECT LOGISTICS

Our tentative dates are June 10-July 12, 2019

Weeks 1-2. We’ll meet at Macalester College and students will be housed in dorms on campus until we depart for the field. While at Macalester, the group will dine in the Macalester dining hall, but there will be some opportunities to shop and cook dinners together, independent of the project leaders but with the help of their peer mentor. These weeks will be spent in the classrooms and laboratories at Macalester, where students will be introduced to the project through a series of focused lectures, discussions, hands-on experiences (e.g., fossil ID, methods of taphonomic characterization, bone histology). Students will process fossiliferous matrix and recover and identify fossils, The team will collect data and craft abstracts for the 2019 GSA meeting (to be submitted no later than June 25, 2019).

Weeks 3-4. We’ll depart Macalester and travel to Montana where we’ll visit a number of Cretaceous paleontological localities. During this interval we’ll be camping in remote field areas, canoeing and hiking in the search for new localities, cooking at our campsite, and making new fossil collections along the way. Our extended field excursion will include a stay in the Hell Creek Formation near Jordan, Montana, where we’ll connect with a field team from the University of Washington at their camp on the Fort Peck Reservoir. Here students will explore the K-Pg boundary and work to collect matrix and fossils from important Hell Creek fossil localities. From there, we’ll continue on to the Upper Missouri River Breaks National Monument (UMRBNM), where the Judith River Formation is well exposed. Here we’ll meet colleagues from the Bureau of Land Management in Lewistown, Montana, before heading into the Monument to conduct field research using a flotilla of canoes to access remote sites along the Missouri River (Figures 3, 4). When our work in the Judith River Formation is done, we will end our time in Montana with a trip to the Two Medicine Formation (the upland equivalent of the Judith River Formation) at the classic “Egg Mountain” field site, where the first North American baby dinosaurs were recovered in the 1970s. Finally, our trip will conclude with a stopover at the Museum of the Rockies in Bozeman, where our students will examine VMB collections and meet with museum curators, fossil preparators, and educators.

Week 5. We’ll return to Macalester for our last week so that we can integrate materials collected in the field into the collection, and we will assemble the text and imagery for our GSA poster presentations. While at Macalester, the group will dine in the Macalester dining hall (and perhaps shop and cook some dinners together, independent of the project leaders but with the help of their peer mentor).

Safety
The project directors are experienced field scientists with decades of experience working at these remote field localities. They are familiar with safety issues specifically related to wildlife, rapidly changing weather conditions, and canoeing/hiking. There is little question that there are a host of inherent risks in this proposed work, but we will try to minimize this risk through training, communication, assessment of student abilities, and planning. We’ll have a satellite phone and wilderness first aid kits at all localities in case of emergency. Here we briefly address the most common concerns.

Wildlife: We will spend the bulk of our field time camping in remote regions with wildlife including rattlesnakes, black bears, and mountain lions. Students will be trained by the project directors in camping/hiking safety.

Canoes: To collect samples in remote, roadless areas, we will be canoeing to some field sites. Students are required to wear personal flotation devices at all times, and the river shoreline is always visible. Students will always canoe with at least one other person, with clear communication about the planned route and expected time on the water.

Weather conditions: The weather in the Montana can be quite unpredictable and variable, with some days/nights up to 100° F and others at/near freezing temperatures. Heavy rain and wind, hail, and snow are all possible, as are very hot sunny days. Warm clothing and layers are all necessary, including rain gear. A day pack (medium sized backpack) is important for all students so they can carry sufficient clothing, and food every day, including 2-3 large water bottles. Sunscreen, hats and gloves, sunglasses, and sturdy hiking shoes/boots are key for student safety and comfort.

PROFESSIONAL DEVELOPMENT

This Gateway Keck project will allow students to develop skills that will last long after the summer is over in a challenging, but supportive environment. Working and living together in the field, collaborating to complete a project from start to finish, and beginning to develop a network of friends and colleagues all build resiliency, competencies, and expertise. Students will work on real scientific questions, using standard and state-of-the art field and lab equipment; they will also receive training in professional science communication. In addition, students will have chances to interact with people across the workforce working as professional geoscientists, from graduate students, professors (the PIs, as well colleagues from the University of Washington and Montana State University), museum professionals (at the Science Museum of Minnesota and the Museum of the Rockies), to those in government positions (Bureau of Land Management employees). These interactions will help set the stage for a broadened view of where a degree in the geosciences can take you, and open the door for future possibilities.

Selected References

Brinkman, D.B., D.A. Eberth, & P. J. Currie. 2007. From bonebeds to paleobiology: applications of bonebed data. In: R. R. Rogers, D. A. Eberth, and A. R. Fiorillo (eds.), Bonebeds: Genesis, Analysis, and Paleobiological Significance. University of Chicago Press, Chicago.

Brinkman, D.B., A.P. Russell, D.A. Eberth, & J. Peng. 2004. Vertebrate palaeocommunities of the lower Judith River Group (Campanian) of southeastern Alberta, Canada, as interpreted from microfossil assemblages. Palaeogeography, Palaeoclimatology, Palaeoecology 213:295-313.

Demar, D.G., Jr., & B.H. Breithaupt. 2006. The nonmammalian vertebrate microfossil assemblages of the Mesaverde Formation (Upper Cretaceous, Campanian) of the Wind River and Bighorn Basins, Wyoming. In: S. G. Lucas & R. M. Sullivan (eds.), Late Cretaceous Vertebrates from the Western Interior. Bulletin of the New Mexico Museum of Natural History and Science 35:33-53.

Rogers, R.R. 1995. Sequence stratigraphy and vertebrate taphonomy of the Upper Cretaceous Two Medicine and Judith River Formations, Montana. Unpublished Ph.D. Thesis, University of Chicago, Chicago.

Rogers, R.R. 1998. Sequence analysis of the Upper Cretaceous Two Medicine and Judith River formations, Montana: nonmarine response to the Claggett and Bearpaw marine cycles. Journal of Sedimentary Research 68:615-631.

Rogers, R.R. & M.E. Brady. 2010. Origins of microfossil bonebeds: insights from the Upper Cretaceous Judith River Formation of north-central Montana. Paleobiology 36:80-112.

Rogers, R.R. & S.M. Kidwell. 2000. Associations of vertebrate skeletal concentrations and discontinuity surfaces in terrestrial and shallow marine records: a test in the Cretaceous of Montana. Journal of Geology 108:131-154.

Rogers, R.R., K.A. Curry Rogers, B.C. Bagley, J.J. Goodin, J.H. Hartman, J.T. Thole, & M. Zatoń. 2018. Pushing the record of trematode parasitism of bivalves upstream and back to the Cretaceous. GEOLOGY 46: 431-434.

Rogers, R.R., K.A. Curry Rogers, M.T. Carrano, M. Perez, & A. Regan. 2017. Isotaphonomy in concept and practice: an exploration of vertebrate microfossil bonebeds in the Upper Cretaceous (Campanian) Judith River Formation, north- central Montana. Paleobiology 43:248-273.

Rogers, R.R., S.M. Kidwell, A. Deino, J.P. Mitchell, & K. Nelson. 2016. Age, Correlation, and Lithostratigraphic Revision of the Upper Cretaceous (Campanian) Judith River Formation in its Type Area (north-central Montana), with a Comparison of Low- and High-Accommodation Alluvial Records. Journal of Geology 124:99-135.

Sankey, J.T. & S. Baszio (editors). 2008. Vertebrate Microfossil Assemblages: Their Role in Paleoecology and Paleobiogeography. Indiana University Press, Bloomington.

Belize corals

Belize corals

Resilience and decline: Are we at a tipping point for endangered Acropora sp. corals in Belize?

Overview: Acropora cervicornis (Staghorn coral) and Acropora palmata (Elkhorn Coral) have been important coral reef builders throughout the recent geologic past. Yet thriving acroporid populations are now exceptionally rare in the Caribbean. Causes cited for the dramatic decline of this (and other coral) species vary, but are virtually all tied directly or indirectly to human-induced environmental or climatic change. In the most recent years we have seen an explosion of research documenting the rapid decline of corals worldwide, and dire predictions of looming collapse. But hope remains that there may be some coral refugia to withstand collapse long enough for local, regional, or global intervention and/or stabilization to occur. Coral Gardens, Belize is one candidate for persistence of endangered Acropora sp. corals, but for how long, we do not know. It is critical to understand working systems if we hope to promote persistence in coral communities, recruits for transplantation, best practices in management, and an understanding of human/environment interactions moving into a climate-stressed future. This project is aimed at assessing the current status of living acroporid-dominated coral reefs off Ambergris Caye, Belize, and expanding the range of previous work in this area.

Keck Geology students studying corals along a transect.

When: June 14-July 18, 2019 (tentative)

Where: Laboratory work at Washington and Lee University (Lexington, Virginia) and field studies in Ambergris Caye, Belize.

Who: Eight students, a peer mentor (Ginny Johnson, W&L ’20), and project directors Dr. Lisa Greer (Washington and Lee University, [email protected]) and Dr. Karl Wirth ([email protected])

Prerequisites and Recommended Courses: Because this experience is a Gateway Project, there are no specific coursework prerequisites. We are seeking students who are interested in many or all of the following: coral reefs, the fossil record, ecosystem dynamics, geochemistry, human impacts to the environment, natural and manmade climate change, and using field and laboratory methods to explore scientific questions about Earth systems.

All students are required to be capable swimmers. This does not mean that students need be expert swimmers, but that they can be safe in the water for prolonged periods (see below). Soon after acceptance to the project students will be required to submit a completed PADI scuba medical questionnaire (and signed by a doctor for certain pre-existing conditions). Prior to arriving at Washington and Lee for the start of the project participants will submit a signed (by swim coach or athletics staff at their home institution) form certifying that the student can complete the minimum swim skills required for SCUBA certification (swim 200 yards and float/tread water for 10 minutes). These skills will be tested again at the beginning of the confined water scuba training. Students should indicate their comfort in water in their application materials. Students should be willing to live in close quarters, be in the heat and sun for much of the day, be on a boat for much of the day, and work well with others.

Expectations and Obligations:
1. Participation in all project-related work during the summer (5 weeks)
2. Submission of an abstract (individual or in groups) and presentation of a paper (poster or talk) at the Geological Society of America National Meeting in Phoenix, AZ or the American Geophysical Union meeting in San Francisco in Fall 2019 (all expenses covered).

PROJECT DESCRIPTION

The goals of this project are to determine 1) whether acroporid reefs at Coral Gardens, Belize are in recovery or continued decline after Hurricane Earl and whether heat-induced stress dramatically impacted living coral in 2016, 2) the degree to which recent decline has theoretically impacted reef accretion rates at this site, 3) how well our previous remote satellite-based mapping of living coral serves as an accurate predictor of coral abundance, 4) the temporal persistence of corals at this site using radiocarbon and uranium series dating of critical time periods, 5) past environmental conditions using geochemical proxy data, and 6) whether temperature and light data show significant change over the period of study (2011-present) and whether there is environmental heterogeneity across several reef sites. In addition, we will expand the study beyond the area we have been working in since 2011. This project will use photographic, in situ, satellite, and laboratory measurements of coral and algal growth, herbivore density, environmental conditions, and coral chemistry to characterize reef ecosystem dynamics in time and space.

Figure 1: Map of Coral Gardens on the Mesoamerican Barrier Reef off the coast of Belize. Map A shows the relative location in the Caribbean and map B shows the location of Coral Gardens and marine reserves near the study site. Red squares at Coral Gardens (C) mark buoys and straight black lines mark coral transects within the study area. D is a detailed map of live coral produced by 2014-15 Keck students.

Background
Acroporid reefs in decline: Acroporid coral species are currently experiencing massive die-offs throughout the Atlantic basin and A. cervicornis and A. palmata are listed as threatened on the U.S. Department of the Interior Endangered and Threatened Wildlife list. Many scientists fear that A cervicornis may be particularly sensitive to environmental change and the demise of the species may be a sign of impending doom for Caribbean reefs in general (e.g. Precht and Aronson, 2004). A primary cause for collapse is White Band Disease (Rogers, 1985; Aronson and Precht, 2001), but many anthropogenic factors may be enhancing or driving disease effectiveness. Of the human-influenced threats to corals, macroalgae abundance due to overfishing and eutrophication, climate change, and potentially ocean acidification seem most important. In the last few decades reefs have experienced dramatic shifts from coral- to algae-dominated ecosystems (Hughes, 1994; Pandolfi et al., 2005), and it is now abundantly suggested that climate change may induce a massive collapse in coral reefs worldwide (e.g. Hughes et al., 2017; 2018).

Most living A. cervicornis today exist in small patches and isolated colonies, and true A. cervicornis-dominated ‘reefs’ are now rare (Miller et al., 2009). The question of whether the recent die-off of acroporids is anomalous with respect to the geologic record has been a subject of debate. Several key studies on the persistence of A. cervicornis prior to the 1980’s have been from Belize (Aronson et al., 1998; Aronson et al., 2002; Wapnick et al., 2004).

Project Location: Ambergris Caye is an extension of the southernmost Yucatan Peninsula and is situated northeast of mainland Belize. This project will primarily take place at a site called Coral Gardens, off the southern tip of Ambergris Caye, Belize which sits between the 1,116 hectare Hol Chan Marine Reserve, created in 1987, and Caye Caulker Marine Protected Areas (Fig. 1). Coral Gardens has no protected status. The modern Belize barrier reef system began to develop as a fossil reef platform at the peak of the last interglacial, and the youngest limestones exposed on Ambergris date ~125,000 ybp (Mazzullo et al., 1992). Flooding of the platform ~6,500 ybp created extensive lagoonal patch reefs forming inland of the barrier reef crest where Acropora sp. corals have been dominant reef builders off Belize for at least much of the Holocene (Aronson et al., 2002) until the 1980’s.

The center of Coral Gardens is composed of acroporid-dominated patches that are variably connected to one another. Since 2012 the Greer lab has been monitoring live coral cover at Coral Gardens along 5 established semi-permanent transects (Fig. 1). Each transect end has been marked with rebar stakes, underwater buoys, and high resolution GPS measurements (Fig.  2). Each year photographs are taken of individual quadrats placed along each transect. Images are rectified and scaled and live coral is manually segmented as overlays on each quadrat. Areal coverage is quantified using MATLAB and all living coral tips are mapped on each image (Fig. 3). Temperature, light, and conductivity have been measured at up to 15 minute intervals across Coral Gardens and additional reef locations since 2013. In some years (including during a 2014-2015 Advanced Keck project), many other variables have been assessed at Coral Gardens, including genetic diversity, herbivore abundance (fish and urchins), reef bathymetry, and sediment character.

Figure 2: Each reef transect location is marked by rebar stakes, buoys, and GPS coordinates at both ends.

Prior Data from Coral Gardens
Quantitative high-resolution data on percent live coral tissue have been collected from 2012-2018 from Coral Gardens. Coral Gardens was also the subject of a 2014-2015 Advanced Keck Project. Data from prior field studies at Coral Gardens suggested that A. cervicornis populations (as well as A. palmata and the hybrid species A. prolifera) were anomalously healthy and robust at Coral Gardens, Belize. All three acroporid species (A. cervicornis, A. palmata, and A. prolifera) were present, live acroporid tissue abundance was high in many places, actively growing branch tips were common, and new coral recruits could be seen colonizing recently dead coral rubble and framework. However, 2016 saw a significant change in live coral tissue, following high 2016 El Nino temperatures and Hurricane Earl (Normile, 2016). Live coral has declined at every transect site since 2012, but the rate and timing of decline has varied across these sites. There is some hope that corals have ‘stabilized’ at 2 of the 5 locations, and the 2019 data may prove critical to assessing whether this reef can ‘bounce back’ after the challenging conditions of 2016.

Our work to date at Coral Gardens has shown that this location contains some of the largest and most extensive Acropora sp. coral populations yet documented in the Caribbean (Greer et al., 2015; Busch et al., 2016). While we have high-resolution longitudinal data from the 5 established transects at Coral Gardens, reconnaissance data from the 2014-2015 Keck Advanced project revealed many additional areas of Acropora sp. coverage in the wider area around Coral Gardens. The study by Busch et al. (2016) attempted to map these areas using satellite imagery. Initial field verification shows remarkable accuracy of this remote sensing tool. At a time when we are seeing declining live coral cover at our original sites it may now be critical to locate and establish monitoring efforts at additional locations of abundant living coral.

Radiocarbon and high resolution uranium-series data show living Acropora cervicornis coral existed at this site from at least 1915 to 2015 (Waggoner et al., 2015; Greer et al., 2016; and Waggoner, 2016 unpublished thesis). While our last Keck Project focused on determining whether Coral Gardens was a true refugia (in the ecological sense and in geologic time), this study collaboratively aims to determine whether Coral Gardens might remain a refugia, assess the geological impacts of declining coral at this site, and to locate the most promising sites of refuge within a larger geographic area.

Potential Student Projects
We envision a wealth of possible student research projects at this location. Potential student projects include the following:

Project 1: Is live A. cervicornis increasing or decreasing at Coral Gardens and is this reef in a phase transition from coral to algae dominance like most other reefs in the Caribbean? All students will participate in this project to some degree, as they will all contribute in some way to the photographic data analysis. A few students could easily make this the focus of their research experience, and several complimentary, but individual projects could evolve. We will conduct a comparative quantitative analysis of live coral tissue, macroalgae, and bare rock abundance from 2014-2019 to determine whether the coral or algae are increasing or in decline within and between sites at Coral Gardens, but also to what degree coral abundance is heterogeneous across the transect sites (which is clearly the case). 2-3 students.

Project 2: How successful was the Busch et al. (2016) remote sensing method for mapping coral populations, and can we identify and establish new habitat mapping areas in the greater Coral Gardens region? As living coral declines at our original sites it may become imperative that we find additional refugia sites to monitor moving forward. Reconnaissance of potential new acroporid sites based on satellite imagery will also provide the opportunity to better assess the novel Busch et al. (2016) mapping technique. New transects will be established at these sites. 2-3 students.

Project 3: How persistent has acroporid growth been at Coral Gardens through the well-documented period of coral decline and in recent geologic time? We already have data that indicate persistence of coral growth at Coral Gardens. But we have many samples that have not yet been dated. One project could focus on trying to obtain dates from stratigraphic sections with poor age constraint (e.g. 1925-1945 or the 1970’s). Another could focus on preparing modern samples (already in hand) to contribute to a refinement of the radiocarbon calibration curve for the Caribbean (Druffel, 1981; Reimer et al., 2013). This project would involve sample assessment for geochemical analysis (using the SEM and XRD), sample preparation for dating and analysis of geochemical data. 1-2 students.

Project 4: What is the relationship between living coral and overall carbonate budget for Coral Gardens and how heterogeneous is it across time and space? We can determine roughly how much carbonate accretion is taking place at Coral Gardens reef by estimating live coral abundance, and using published data on coral growth rates and skeletal density of coral samples for each transect site and the whole Coral Gardens reef. We can roughly estimate how fast carbonate is being excavated from reef framework by quantifying net annual bioerosion by grazers (fish and urchins) (Griffin et al., 2003 Mumby et al., 2006; Brown-Saracino et al., 2007); and macroborers from the literature (Hubbard et al., 1990; Perry et al., 2013) and the 2014-2015 Keck Advanced project to compare 2019 data with data from past years. We will place our estimates in the context of previous estimates of reef accretion from the literature. A key question centers on the degree to which the decline in live coral that we are observing will impact the geologic system as a whole. This project can easily involve several students with collaborative focus on fish, urchin, and damselfish surveys, net carbonate calculation, and the living coral dataset. 3-4 students.

Project 5: Do environmental measurements show a marked increase in temperature, conductivity, and/or light at this site from 2012-2019, and to what degree are these changes synchronous off the coast of Ambergris Caye? We have been collecting temperature data at 15 minute intervals across Coral Gardens, on land, and at additional sites (Manatee Channel to the south, and Rocky Point to the north) since 2012. We also have variable conductivity and light data from several sites. These sites span the length of Ambergris Caye, variable shallow depths, and variable exposure to open-marine water. A key question we originally asked of this project (in 2011) was what is contributing to the survival of the Coral Gardens refugia? To date we have not done a systematic analysis of the environmental data to see whether temperature at this site may have contributed to success (via exposure to flushing of ‘new’ and possibly cooler water from outside the reef), and whether temperatures are now exceeding the recent norm at this site. 1 student.

Project 6: Do stable isotope measurements from corals living over the last 100 years show a changing environment? We have Acropora cervicornis samples dating from at least 1915-2015. Very few of these samples have been analyzed for stable isotopic composition. Following a framework used by Greer et al. (2009) to investigate temperature changes crossing the mid-Holocene Thermal Maximum, we could pair radiocarbon dates with stable isotope composition to see if there are any discernable trends in temperature at this site (assuming salinity has roughly remained the same) over the last 100 years. If we could detect change on that scale, it might be the first to do so using this species of coral. 1-2 students.

Figure 3: Image A shows placement of a quadrat along an established transect and B shows the original photograph. C shows a rectified and scaled image (using MATLAB) and D shows the manual tracing of live coral cover. E shows the same image used to quantify live coral using MATLAB and F shows a map of living coral branch tips.

PROJECT LOGISTICS

Students will complete an online SCUBA knowledge course prior to the start of the project period. This course develops the knowledge base needed for SCUBA certification.

Washington and Lee University: We will spend approximately 1 week in Lexington prior to departure for Belize. The focus of this week is to explore important concepts in reef science, and develop the knowledge and skills needed for field research. Students will learn about the methods we will use, explore prior data from Coral Gardens, and learn to identify the major corals and reef organisms. We will also complete the early portion of the SCUBA certification in the W&L swimming pool.

Belize: We will spend approximately 2 weeks in Belize collecting data from the field sites using both snorkel and SCUBA. In addition to conducting all aspects of the field work, students will also complete the open-water dives for SCUBA certification, and participate in field lectures by Dr. Ken Mattes (TREC Belize; Fig. 4) and snorkeling experiences in a variety of reef habitats. We hope to also take one day to visit Mayan ruins and talk about the impacts of climate change on the Mayans.

Washington and Lee University: We will spend the last two weeks of the project period at Washington and Lee. Here students will learn analytical and computational techniques and they will quantify/analyze data. They will use the X-Ray Diffractometer (Fig. 5), Scanning Electron Microscope, High-Resolution Micromill, and Stable Isotope Mass Spectrometer. Students will process photographic data using a number of software programs including MATLAB and analyze large environmental datasets using excel. In the last week we will work with students to craft posters and abstracts, for presentation at a Fall national Geosciences meeting (GSA in Phoenix or AGU in San Francisco).

Figure 4: Accommodations at the TREC Belize research station.

Figure 5: Keck Geology students using the x-ray diffractometer to study Belize samples.

Figure 6: Keck Geology student studying Belize samples using a scanning electron microscope (SEM).

PROFESSIONAL DEVELOPMENT

Conducting a research project at an early career stage is not only a résumé-builder, but helps to develop knowledge and skills that are important to many educational, career, and life goals. Working and living together in a supportive yet challenging environment, completing a collaborative project from start to finish, and starting to develop a network of friends and colleagues all build identity as a scientist, resiliency, capabilities, and cognitive abilities. Students will work on authentic scientific questions and be trained to use state-of-the art equipment and methods. Project participants will also learn to communicate the results of their scientific investigations in both informal (e.g., general public) and formal (e.g., other professionals in the discipline.

References

Aronson, R.B., Macintyre, I.G., Precht, W.F., Murdoch, T.J.T., and Wapnick, C. M., 2002, The expanding scale of species turnover events on coral reefs in Belize. Ecological Monographs 72:233–249.

Aronson, R.B. and Precht, W.F., 2001, White-band disease and the changing face of Caribbean coral reefs. Hydrobiologia, 460:25-38.

Aronson, R.B., Precht, W.F., and Macintyre, I.G., 1998, Extrinsic control of species replacement on a Holocene reef in Belize: the role of coral disease. Coral Reefs, 17:223- 230.

Brown-Saracino, J., Peckol, P., Curran, H.A., Robbart, M.L., 2007, Spatial variation in sea urchins, fish predators, and bioerosion rates on coral reefs of Belize. Coral Reefs 26 (1):71-78.

Busch, J., Greer, L., Harbor, D., Wirth, K., Lescinsky, H., and Curran, H.A., 2016, Quantifying exceptionally large populations of Acropora spp. corals in Belize using sub-meter satellite imagery classification. Bulletin of Marine Science, v.92, pp. 265-283. http://dx.doi.org/10.5343/bms.2015.1038

Druffel EM (1981) Radiocarbon in annual coral rings from the eastern tropical pacific ocean. Geophysical Research Letters, 8(1), 59-62. doi: 10.1029/GL008i001p00059.

Greer, L., Jackson, J., Curran, H.A., Guilderson, T., and Teneva, L., 2009, How vulnerable is Acropora cervicornis to environmental change? Lessons from the early to mid-Holocene. Geology, 37:263-266.

Greer L, Lescinsky H, Wirth K., 2015, Multi-level characterization of acroporid coral populations at Coral Gardens, Belize: A refugia identified. Proceedings of the 28th Annual Keck Research Symposium in Geology. Schenectady, New York, April 2015.

Greer, L, Waggoner, T, Guilderson, T, Clark, T, Curran, HA, Busch, J, Lescinsky, H, Wirth, K, Harbor, D, 2016, Coral Gardens Belize: An Acropora spp. refugia identified. 13th International Coral Reef Symposium, Honolulu, Hawaii.

Griffin, S.P., Garcia, R.P., and Weil, E., 2003, Bioerosion in coral reef communities in southwest Puerto Rico by the sea urchin Echinometra viridis. Marine Biology, 143: 79084.

Hubbard, D.K., Miller, A.I., and Scaturo, D., 1990, Production and cycling of calcium carbonate in a shelf-edge reef system (St. Croix, U.S. Virgin Islands); applications to the nature of reef systems in the fossil record. Journal of Sedimentology, 60:335-360.

Hughes, T.P., 1994, Catastrophes, phase shifts, and large-scale degradation of a Caribbean coral reef. Science, 265(5178):1547-1551.

Hughes et al., 2017, Global warming and recurrent mass bleaching of corals. Nature, 543, 373–
377, doi:10.1038/nature21707pmid:28300113.

Hughes et al., 2018, Spatial and temporal patterns of mass bleaching of corals in the Anthropocene, Science, 359:80-83. DOI: 10.1126/science.aan8048.

Mazzullo, S.J., Anderson-Underwood, K.E., Burke, C.D., and Bischoff, W.D., 1992, “Holocene coral patch reef ecology and sedimentary architecture, northern Belize, Central America.” Palaios, 7(6):591-601.

Miller, S.L., Chiappone, M., Rutten, L.M., and Swanson, D.W., 2009, Population status of Acropora corals in the Florida Keys. Proc. of the 11th Int. Coral Reef Symp., Ft. Lauderdale, FL, 775-779.

Mumby, P.J., Dahlgren, C.P., Harborne, A.R., Kappel, C.V., Micheli, F., Brumbaugh, D.R., Holmes, K.E., Mendes, J.M., Broad, K., Sanchirico, J.N., Buch, K., Box, S., Stoffle, R.W., and Gill, A.B., 2006, Fishing, trophic cascades, and the process of grazing on coral reefs. Science, 311 (5757):98-101. DOI: 10.1126/science.1121129

Normile, D., 2016, El Niño’s warmth devastating reefs worldwide, Science, 352:15-16, DOI:
10.1126/science.352.6281.15

Pandolfi, J.M., Jackson, J.B.C., Baron, N., Bradbury, R.H., Guzman, H.M., Hughes, T.P., Kappel, C.V., Micheli, F., Ogden, J.C., Possingham, H.P., and Sala, E., 2005, Are U.S. coral reefs on the slippery slope to slime? Science, 307:1725–1726, DOI: 10.1126/science.1104258.

Perry, C.T, Murphy, G.N., Kench, P.S., Smithers, S.G., Edinger, E.N., Steneck, R.S., and Mumby, P.J., 2013, Caribbean-wide decline in carbonate production threatens coral reef growth. Nature Communications, 4:1402, DOI: 10.1038/ncomms2409.

Precht, W.F. and Aronson, R.B., 2004, Climate flickers and range shifts of reef corals, Frontiers in Ecology and the Environment, 2:307-314.

Reimer PJ, Bard E, Bayliss A, Beck JW, Blackwell PG, Bronk-Ramsey C, Grootes PM, Guilderson TP, Haflidason H, Hajdas I, HattŽ C, Heaton TJ, Hoffmann DL, Hogg AG, Hughen KA, Kaiser KF, Kromer B, Manning SW, Niu M, Reimer RW, Richards DA, Scott EM, Southon JR, Staff RA, Turney CSM, van der Plicht J (2013) IntCal13 and Marine13 Radiocarbon Age Calibration Curves 0-50,000 Years cal BP. Radiocarbon, 55(4).

Rogers, C.S., 1985. Degradation of Caribbean and western Atlantic coral reefs and decline of associated fisheries, in Proceedings of the fifth international coral reef congress, Tahiti, C. Gabrie and M. Harmelin-Vivien, editors. Volume 6. Antenne Museum-EPHE, Moorea, French Polynesia, 491-496.

Waggoner, T., Greer, L, Guilderson, T, Clark, T, Busch, J., Biegel, J., Lustig, H., Curran, HA, Lescinsky, H, Wirth, K, 2015, Chronological persistence of Acropora cervicornis at Coral Gardens, Belize. GSA Abstracts with Programs Vol. 47, No. 7.

Waggoner, T. (’16, Honors), 2016, Chronological Persistence of Acropora cervicornis at Coral Gardens, Belize. Honors Thesis

Wapnick, C.M., Precht, W.F., and Aronson, R.B., 2004, Millennial-scale dynamics of staghorn coral in Discovery Bay, Jamaica. Ecology Letters, 7(4):354-361.

Assessing vegetation and fluvial responses to the PETM

Assessing vegetation and fluvial responses to the PETM

Assessing vegetation and fluvial responses to the Paleocene-Eocene Thermal Maximum in the Hanna Basin (Wyoming, U.S.A.)

Overview: This project focuses on developing the basin evolution and paleobotanical history of the Hanna Basin spanning the transition between the Paleocene and Eocene epochs. Globally a greenhouse climate state dominated the early Paleogene, and in the Western Interior of the United States the Laramide Orogeny produced a series of uplifts and sedimentary basins. Overall the paleoclimate appears to become drier and potentially more seasonal between the Paleocene and Eocene, likely related to global warming trends and changing topography due to uplift of the Rocky Mountains. In several basins there are attendant shifts in fluvial and floodplain deposition indicating drier and more seasonal conditions as well as moderate shifts in floral communities. However, the Hanna Basin of south-central Wyoming appears anomalous. Initial studies suggest this area remained largely wet and humid, defying regional trends. This uniqueness is particularly important because the basin likely contains one of the most stratigraphically-expanded records of the Paleocene-Eocene Thermal Maximum (PETM) of anywhere in the world.

Searching for fossil ferns in the Hanna Basin, Wyoming

The PETM is an abrupt global warming event linked to the massive release of carbon into Earth’s atmosphere and oceans (McInerney & Wing, 2011). In other basins in the Rocky Mountain region it is correlated to substantial changes in the hydrologic cycle exacerbating seasonality in rainfall and vegetation overturn (Wing et al., 2005; Foreman et al., 2012; Kraus et al., 2015). The effects in the Hanna Basin are largely unknown and may be unique in their character. Student projects will focus on one of three topics: (1) reconstruction of paleoenvironment from fluvial and floodplain deposits and recovering information on ancient landscape dynamics; (2) understanding the interacting components of the local to global carbon cycle through stable carbon isotope records; and (3) characterizing vegetation cover spanning the short- and long-term climate changes using a new plant cuticle-based proxy method.

When: July 6 – August 5, 2018

Where: Laramie, Wyoming (introduction and lab work) and Hanna, Wyoming (field work)

Who: Four to six students and project leaders Dr. Brady Foreman (Western Washington University, [email protected]) and Dr. Ellen Currano (University of Wyoming, [email protected]). USGS stratigrapher Marieke Deschesne and Field Museum paleobotanist Dr. Regan Dunn will also take part in field and lab work and provide additional mentorship for student projects.

Prerequisites and Recommended Courses: Suggested (but not required) are core courses in the Geology major: Historical Geology, Structure/Tectonics, Stratigraphy, Mineralogy, Paleontology and Geochemistry. Students should have completed key cognate courses in Chemistry and Math. Experience at a field camp or in a field geology course is recommended but not required.  We are particularly interested in applicants with an interest in Paleoclimates, who have a high degree of comfort in rugged outdoor settings, are able to hike several miles in warm temperatures (on occasion greater than 95° F in the high desert climate), are flexible eaters, and who want to use this work to complete a senior thesis (or equivalent) in geology. Helpful, but not required in the letter of recommendation from the on-campus sponsor is an indication of how well the applicant will function in a remote field setting with primitive camping (i.e., no running water, no bathrooms, limited cell phone service).

Expectations and Obligations:

  1. Participation in all project-related work during the summer (July 6-August 5, 2018).
  2. Follow up data analysis at home institution and regular conference calls with research team throughout academic year.
  3. Write an abstract and present a paper (poster or talk) for the Geological Society of America Rocky Mountain Section meeting in Manhattan, Kansas (conference is March 25-27, 2019).
  4. Write a short contribution (4-6 pages text + figures) to be published in the Proceedings of the Keck Geology Consortium 2019 Volume (first draft due Mid-February).
  5. Expected but not required: Use this work for the completion of a senior thesis (or equivalent) at your home institution.

PROJECT DESCRIPTION

Geologic Overview

The Paleocene-Eocene Thermal Maximum is viewed as one of the premier geologic analogs for modern, anthropogenic global warming. However, our understanding of the major terrestrial impacts is limited to one well-documented example (Bighorn Basin of northwest Wyoming) and a few other locations globally where only a few key hydrologic or temperature constraints exist. Broadly speaking, the terrestrial response to elevated carbon dioxide levels is expected to be highly variable due to topographic variability and shifting atmospheric circulation patterns under different latitudinal thermal gradients. As such it is critical to develop additional continental locations where the temperature, hydrologic, and biologic changes are constrained. The Hanna Basin is a logical extension of the work in the Bighorn Basin, and, more importantly, a key example for changes that may mimic those predicted for modern river and vegetation systems during future anthropogenic climate change.

The Hanna Basin record is a particularly important complement to the record already collected in the Bighorn Basin because stratigraphic data suggest a difference in water availability between the two basins. Both the PETM interval and the entire early Eocene sequence preserved in the Willwood Formation in the Bighorn Basin contain abundant red beds, indicative of well-drained soils and seasonal precipitation (Kraus and Riggins, 2007; Kraus et al., 2015). The Bighorn Basin records the consequences of a semi-arid basin experiencing an abrupt global warming event. In contrast, the Hanna Basin sedimentary sequence remains drab-colored and coal-rich from bottom to top, suggesting that wet, swampy conditions prevailed through the PETM and early Eocene (Dechesne et al., in prep). It records the consequences of a more humid basin experiencing an abrupt global warming event. Thus, comparisons of the Hanna and Bighorn basins will allow us to disentangle the roles of temperature and water availability in driving vegetation change and the fluvial response in a dominantly humid setting. This water availability difference is likely due to the location of the Hanna Basin, farther to the east and potentially more proximal to moisture sources as compared to the Bighorn Basin (Sewall & Sloan, 2006). The Laramide Orogeny created a complex topography within the Western Interior that strongly influenced water vapor transport paths (Sewall & Sloan, 2006). In general, however, circulation models suggest the easternmost Laramide basins were wetter as moisture from the paleo-Gulf of Mexico moved north and westward. This resulted in semi-arid and dry conditions in the western and northernmost Laramide basins (Sewall & Sloan, 2006).

Figure 1: Cretaceous to Eocene sedimentary strata of the Hanna Basin, Wyoming.

Study Area

The targeted field area for this study is the Hanna Basin of south-central Wyoming near the small town of Hanna. The Hanna Basin is a Laramide style basin bounded by the Rawlins uplift to the west, Sweetwater Arch in the north, the Simpson Ridge anticline in the east, and the Medicine Bow and Sierra Madre Mountains in the south. It is exceptional among the Laramide basins because of its high subsidence rate, extremely thick Cretaceous to Eocene sedimentary strata, and extensive coal deposits (Dobbin et al., 1929; Roberts and Kirschbaum, 1995; Wroblewski, 2003). The Paleocene-Eocene boundary is preserved in the Hanna Formation, which is over 2000 meters thick at the center of the basin (WOGCC, 2016; Gill et al., 1970; Wrobleski, 2003) and consists of conglomerates, sandstones, siltstones, carbonaceous shales, and coals. These deposits are interpreted as low gradient fluvial to paludal and lacustrine (Dobbin et al, 1929; Wrobelski, 2003; Lillegraven et al., 2004). The student projects will target a specific set of extensive outcrops along the Hanna Draw Road and in “The Breaks,” which have been the focus of new geologic and paleontologic work by Currano, Dechesne, and Dunn. The majority of research will focus on a 250-meter thick stratigraphic interval with pollen biostratigraphic constraints and initial bulk d13C values that indicate the PETM is preserved.

Goals and Significance of the Project

Overall the goal of the project is to characterize fluvial and vegetation changes spanning the transition between the Paleocene and Eocene epochs in the Hanna Basin of Wyoming. This is a critical time period in the history of life and the evolution of the Rocky Mountain region. Specifically, there were transitory changes in paleo-plant communities, persistent shift in the mammalian biogeography, and a general warming and drying trend in the Western Interior of the United States. The Hanna Basin potentially records the most complete history of this transition because it witnessed the fastest sedimentation rates of any Laramide basin in the region. This broad goal requires (1) refining the chronstratigraphy of the basin using pollen fossils and carbon isotope records; (2) detailed lithofacies analysis and outcrop mapping; and (3) application of new cuticle-based proxies for vegetation cover.

Student Projects

Student projects will be sub-divided into three discipline related groups. These groups entail Sedimentology-, Geochemistry-, and Paleobotany-themed projects. All students will receive training and gain experience in the three disciplines, and interact extensively with other students, faculty, and collaborators. However, the specific projects they pursue will fall into one of these three categories. Sedimentology projects will involve detailed lithofacies analysis and paleoenvironmental reconstructions of the river and floodplain deposits (n = 1 student project). These students will develop field datasets that address key questions regarding river channel morphology, avulsion behavior, floodplain drainage, and overbank flooding frequency. The majority of data can be derived from the detailed stratigraphy section we will measure at Hanna Draw area. A separate Sedimentology project (n = 1 student project) will focus on mapping out and describing the larger alluvial architecture of the fluvial sandbodies. This entails identifying and tracing out the amalgamation of distinct channel occupation events and the lateral migration of channel bodies. This information will yield insights into the mobility and paleo-dynamics of the ancient river systems.

The Geochemistry-themed projects will focus on developing a detailed δ13C bulk organic isotope stratigraphy through the 250 meters of section thought to contain the PETM (n = 2 student projects). This will entail a combination of stratigraphic section measuring (fieldwork), and sample preparation at the University of Wyoming. This includes powdering rock samples, acid digestion, and distilled water treatments, followed by drying and weighing steps. Time permitting students will run samples themselves on the Isotope Ratio Mass Spectrometers at the University of Wyoming Stable Isotope Facility. Two students will focus on this component of the project. One student will recover secular variation from densely sampled (every 0.5 m or finer) vertical samples distributed throughout the 250-meter target interval. A second student will focus on constraining lateral variability of the isotope signals. Since bulk organic δ13C records mix vegetative matter from several different types of plants it is important to constrain the total amount of variability across a landscape. This is rarely done in ancient strata (Magioncalda et al., 2004; Foreman et al., 2012), and this student will produce one of the most detailed evaluations of this uncertainty to date.

Paleobotany-themed projects will utilize a new proxy for vegetation cover that uses leaf epidermal cell size and shape to reconstruct leaf area index (LAI=foliage area/ground area; Dunn et al., 2015). This proxy has been effectively used to correlate changes in vegetation cover in South America to environmental changes, as well as to vertebrate evolution. The work in the Hanna Basin will be the first attempt to quantitatively document changes in vegetation structure across the Paleocene-Eocene boundary. The samples contain fragments of fossil leaf cuticle that preserve epidermal cell morphology. Students will photograph cuticle fragments using the microscope set-up in Currano’s lab, measure leaf epidermal cell size and shape using a Wacom Cintiq tablet and ImageJ, and reconstruct LAI using regression equations between size and shape parameters and LAI produced by Dunn from using a modern calibration datasets (Dunn et al., 2016). One student will analyze the vertical transect and a second will analyze a set of lateral samples by tracing out a stratigraphic marker bed over several 100’s of meters. This approach will allow both temporal and spatial changes in vegetation to be constrained.

Summary of Projects

Student 1: Lithofacies analysis of fluvial and overbank facies

Student 2: Mapping and description of sandbody geometries and floodplain relationship

Student 3: δ13C bulk organic isotope stratigraphy vertical variation

Student 4: δ13C bulk organic isotope stratigraphy lateral variation

Student 5: Cuticle variability and vegetation cover, vertical section

Student 6: Cuticle variability and vegetation cover, lateral section

Figure 2: Measuring section using a Jacob’s staff.

PROJECT LOGISTICS

The planned projects will involve 4-6 undergraduate students at junior and senior levels in their academic career. Students and faculty will rendezvous at the University of Wyoming on July 6 where initial gear checks will occur, and safety procedures and project details will be presented by faculty members. After this orientation we will proceed to the field area near Hanna, Wyoming (~2 hour drive). Field transport will include a rented university vehicle and two private vehicles. The field area is remote, but camping will occur in close proximity to vehicles. Our camp will be set up on public (BLM) lands, and will be primitive (i.e., no running water, no toilets, limited cell phone service). The first field day will entail a tour of the study area, an overview of the depositional history of the basin, and an additional field safety orientation. Subsequently, the students will be subdivided into the sedimentology, geochemistry, and paleobotany research groups and begin their projects. The remainder of the time will be divided into four phases:

Phase 1 (07/07 thru 07/14): Fieldwork

  • main stratigraphic section measuring (3 students)
  • outcrop mapping (1 students)
  • paleobotanical excavation (2 students)

Phase 2 (07/15 thru 07/23): Field and Lab work

  • main stratigraphic section measuring & outcrop mapping (2 students)
  • paleobotanical excavation (2 students)
  • geochemistry sample preparation (2 students)

Phase 3 (07/24 thru 08/05): Field and Lab work

  • main stratigraphic section measuring/outcrop interpretation (2 students)
  • paleobotanical proxy training (2 students)
  • geochemistry sample preparation (2 students)

Phase 4 (March, 2019): Professional Development Component

  • poster presentations at Rocky Mountain Section GSA meeting

The expectations for students include (1) a positive, flexible attitude, (2) a responsiveness to the needs of the group, (3) a collaborative mentality, (4) strong work ethic, and (5) interest in developing quantitative and interpretative skills. These will be rough working conditions. Temperatures can exceed 95º F in the high desert climate of Wyoming. Strong winds and intense rainstorms are also likely. Students will be expected to have appropriate field gear (e.g., boots, hat, sunglasses, tent, sleeping bag, sleeping pad, backpack, water bottles). Students will need to be physically fit, and able to walk several miles per day on steep slopes in the heat, dig quarries that requires the use of shovels and pickaxes, and be capable of carrying and packing out over 30 lbs of rock per day over 3 miles. Days will likely be long, in excess of eight hours. Dietary restrictions will be accommodated if possible. Each research sub-group will be expected to produce a cohesive presentation for the annual Rocky Mountain Section meeting of GSA in May 2019 (location of meeting is unannounced). Faculty advisors will coordinate with the students towards this endeavor and aid in the construction of the poster presentation. All students will be expected to attend the meeting and participate in associated activities.

WYOMING SAFETY ISSUES

As with any field and lab work there will be safety concerns. Field risks include dehydration, heat stroke, exhaustion, sunburn, insect bites, poisonous snakes, and physical injuries such as sprained ankles and broken bones. Lab risks are relatively minor, but include the use of (weak) acids when preparing stable isotope samples and airborne dust respiratory concerns when handling and preparing plant fossils. Risks will be mitigated by following proper training protocols, outlining and identifying the risks, and holding several safety meetings. Faculty associated with the project have extensive experience in all pertinent field and lab methodologies, wilderness first aid training, and will coordinate with lab technicians to maintain safety standards.

The faculty members involved in this project and collaborators collectively have over 30 field seasons of experience working in the region. They have published over 15 scientific articles and reports on the field area and equivalent rocks in the Laramide basins of the western United States. All have led several field crews of undergraduate and graduate students under similar circumstances. Foreman and Dechesne are certified in wilderness first-aid, and we will be maintaining a list of nearby medical facilities in case of emergency. In terms of professional expertise Dr. Brady Foreman (WWU) and Marieke Dechesne (USGS) are sedimentary geologists who have worked extensively in the surrounding Laramide and Sevier foreland basin deposits. Dr. Ellen Currano (University of Wyoming) and Dr. Regan Dunn (Field Museum) are paleobotanists who have worked extensively on cuticle and plant macrofossil records in the region. Dechesne, Dunn, and Currano have collected the initial datasets upon which this proposal is based, and have identified specific areas in the basin to target for this study. This will maximize the chances of research success for the students. Foreman and Dechesne will advise students with sedimentologic projects, paleobotany projects will be advised by Currano and Dunn, and geochemistry projects will be advised by Foreman and Currano.

Figure 3: Cnemidaria fern fossil.

PROFESSIONAL DEVELOPMENT

We plan to take all participants to the GSA Rocky Mountain section meeting in Manhattan, Kansas (25–27 March 2019).  We hope most students will be first author on one paper, and probably secondary authors on others due to the collaborative nature of the project.

All students are required to complete a 4-6 page paper (short contribution) that will be published in the Proceedings of the Keck Geology Consortium 2019 Volume (see examples from previous years). The first draft of this paper will be reviewed by your research advisor at your home institution sometime in late February, 2019, with the revised version sent to the project directors by March 1.  Final versions of your paper and figures will be submitted to the Keck Office in Mid-March.

References

Bataille, C.P., Watford, D., Ruegg, S., Lowe, A., Bowen, G.J. 2016. Chemostratigraphic age model for the Tornillo Group: A possible link between fluvial stratigraphy and climate. Palaeogeography, Palaeoclimatology, Palaeoecology 457: 277-289.

Bowen, G.J., Bowen, B.B. 2008. Mechanisms of PETM global change constrained by a new record from central Utah. Geology 36: 379-382.

Clechenko, E.R., Kelly, D.C., Harrington, G.J., Stiles, C.A. 2008. Terrestrial records of a regional weathering profile at the Paleocene-Eocene boundary in the Williston Basin of North Dakota. GSA Bullletin 119: 428-442.

Dechesne, M., Currano,  E.D., Dunn, R.E., Higgins, P., Hartman, J., Chamberlain, K. (in preparation). Climatic and tectonic responses of the fluvial to paludal strata of the Hanna Formation around the Paleocene-Eocene Boundary, Hanna Basin, Wyoming.

Dobbin, C.E., Bowen, C.F., Hoots, H.W. 1929. Geology and coal and oil resources of the Hanna       and      Carbons basins, Carbon County, Wyoming. U.S. Geological Survey Bulletin 804: 88.

Dunn, R. E., C. A. E. Strömberg, R. H. Madden, M. J. Kohn, and A. A. Carlini. 2015. Linked canopy,          climate, and faunal change in the Cenozoic of Patagonia. Science 347(6219):258-261.

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