INCREASING THE RESOLUTION OF THE LAST GLACIAL MAXIMUM RECORD IN THE TROPICAL ANDES USING 10Be COSMOGENIC SURFACE-EXPOSURE DATING IN THE CORDILLERA CARABAYA, PERU
Author: Zachary E. Mason
Major: Earth and Climate Sciences
Graduation Year: 2016
Thesis Advisor: Brenda L. Hall
Description of Publication: Owing to the abundance of heat and moisture, the tropics is a fundamental component of the global climate system. Yet the role of the tropics in climate remains poorly understood. The Andes are home to ~95% of all tropical glaciers, making this the ideal region for studying relationships between tropical glaciers and climate. I conducted a Beryllium-10 surface exposure dating experiment using ten quartz-bearing rock samples from a series of last glacial maximum (LGM) moraines in the Minas Tira glaciofluvial valley system, Cordillera Carabaya, Peru. The AMS measured sample dates (excluding outliers) range from 24.3 ± 0.5 ka to 19.4 ± 0.5 ka, and give an average of 22.3 ± 1.5 ka. On a first order basis, this average fits within the global LGM timescale of 23–19 ka, supporting the view of contemporaneous glaciation between the hemispheres and a globally uniform ice age. My data also align broadly with the global CO2 record, supporting – though not confirming – the hypothesis that atmospheric CO2 levels are closely linked to temperature changes during deglaciation.
Location of Publication:
URL to Thesis: https://digitalcommons.library.umaine.edu/honors/398