Start |Author Index | View Uploaded Presentations | Meeting Information

GSA Annual Meeting in Indianapolis, Indiana, USA - 2018

Paper No. 225-9
Presentation Time: 10:35 AM

COSMOGENIC 10BE SURFACE EXPOSURE DATING AND NUMERICAL MODELING OF LATE PLEISTOCENE GLACIERS AND LAKES IN NORTHWESTERN NEVADA


FLEMING, Kaitlyn C., Environmental and Conservation Sciences, North Dakota State University, 1340 Administration Ave, Fargo, ND 58105, LAABS, Benjamin J., Geosciences, North Dakota State University, Stevens Hall, 1340 Bolley Dr #201, Fargo, ND 58102 and MUNROE, Jeffrey S., Geology Department, Middlebury College, 276 Bicentennial Way, Middlebury, VT 05743

The Great Basin region of the southwestern United States features a rich geologic record of Pleistocene climate change. The timing of the last Pleistocene glaciation in mountains of the northwestern Great Basin is poorly known, however, especially compared to the timing of pluvial lake highstands. This study focuses on the glacial record in the Pine Forest and Santa Rosa Ranges, utilizing cosmogenic beryllium-10 surface exposure dating to develop a chronology of moraines and numerical modeling of glaciers to infer climate during the last glaciation. Preliminary cosmogenic exposure ages in the Santa Rosa Range support the idea that glacier maxima and lake highstands occurred at the same time and indicate that the timing of glacier maxima in the Santa Rosa Range was similar to that in other mountains of the northern Great Basin. Results of numerical model experiments that simulate Last Glacial Maximum (LGM) and Lateglacial ice extents include a range of temperature and precipitation combinations accompanying glacier maxima in the northwestern Great Basin. If precipitation in the Pine Forest Range was similar to modern, then the temperature depressions during the last glaciation were -9 to -8 °C. If precipitation in the Santa Rosa Range was similar to modern, then the temperature ranges were -6 to -5 °C. Temperature-precipitation combinations for the Pine Forest Range compare favorably with results of model applications to other mountains in the northern Great Basin. Model results for the Santa Rosa Range,however, suggest that these mountains experience either a lesser temperature depression or drier conditions compared to other mountains of the northern Great Basin. Overall, the chronology of glacial deposits in the northwestern Great Basin and inferred climate during the last glaciation show consistency acrosst the northern Great Basin and suggest that precipitation in the region was similar to modern.

Session No. 225

T56. From Alpine Glaciers to Ice Sheets: Understanding Glacial Dynamics, Landscapes, and Environmental Change
Wednesday, 7 November 2018: 8:00 AM-12:00 PM
Room 136-137 (Indiana Convention Center)
Geological Society of America Abstracts with Programs. Vol. 50, No. 6
doi: 10.1130/abs/2018AM-320730
© Copyright 2018 The Geological Society of America (GSA), all rights reserved. Permission is hereby granted to the author(s) of this abstract to reproduce and distribute it freely, for noncommercial purposes. Permission is hereby granted to any individual scientist to download a single copy of this electronic file and reproduce up to 20 paper copies for noncommercial purposes advancing science and education, including classroom use, providing all reproductions include the complete content shown here, including the author information. All other forms of reproduction and/or transmittal are prohibited without written permission from GSA Copyright Permissions.
Back to: T56. From Alpine Glaciers to Ice Sheets: Understanding Glacial Dynamics, Landscapes, and Environmental Change
<< Previous Abstract | Next Abstract >>