Volcanoes of the Aleutian arc have erupted intermittently during the last three million years, and biostratigraphy indicates that the marine sediments have accumulated in a subduction zone setting since the Miocene, however, previous studies of Aleutian volcanoes have focused primarily on the main stratocones and satellite cinder cones that have erupted in the Holocene. On Unalaska Island, Makushin Volcano and its satellite vents have erupted on older lavas and pyroclastic deposits, yet these Pleistocene lavas, which cover approximately 600 km2, are virtually unstudied. We propose to map and sample the Pleistocene pre-Makushin lavas, which will facilitate subsequent lab-based investigations into the timing and development of the pre-Makushin magmatic system.
This project is based in the High Cascades of central Oregon and the Deschutes Basin and integrates studies of bedrock, soil, and water chemistry. The project will focus on physical and chemical weathering of volcanic rocks and factors that can influence the weathering processes, including climate and vegetation. We will attempt to trace geochemical signatures of the bedrock as it breaks down into soil. We will also study the water geochemistry to assess the effects of the bedrock and soil composition on the fluxes from the watershed.
We propose to investigate Holocene high lake stands in closed basin lakes of Alaska’s Kenai Peninsula. Preliminary dating of these relative high stands suggests an early to mid-Holocene age. This proxy for increased precipitation can serve as a test to hypotheses concerning the relative roles of the tropics and higher latitudes in moisture budgets across western North America and ultimately serve to predict moisture variability with a warming climate.
This study will use a multi-disciplinary approach to unravel the depositional history of the Kootznahoo Formation in Southeast Alaska with a specific focus on the exhumation history of the Coast Mountains batholith (CMB), and how high latitudes (~57°N) recorded overall global cooling from the Paleocene-Eocene thermal maximum (PETM) through the Eocene-Oligocene transition to the present icehouse state.