Understanding Glacial Patterns Within Lake Sediments of The Peruvian Andes

Variations in the timing and magnitude of clastic sediment flux to proglacial lakes can yield insight into glacial fluctuations and dynamics throughout the recent interglacial period. This project focuses on a glacial lake within the Cordillera Central of the Peruvian Andes, Huaylillas, at ~4000 m elevation and aims to build essential. The study site at Huaylillas is significant due to its placement as the 4th body in a chain of lakes forming from the advance and retreat of the imposing glacier. In 2017 a 5.2 m overlapping sediment record was collected and analyzed for glacial-interglacial transitions in which radiocarbon and 210Pb dates were used to create an age model for the core dating back to ~18 kyr BP. An age model created using Monte-Carlo Bayesian statistics. Additional measurements included magnetic susceptibility, bulk density, organic/carbonate content, XRD, and SEM identification of sediment mineral phase content. Stratigraphy and sedimentology at Huaylillas indicate glacial pulses and interglacial periods which present themselves as iron rich clay and organic rich sediments respectively. These units vary in size with glacial pulses ranging from a few centimeters to over 1 m which may suggest that the duration of glacial pulses and interglacial intervals has been variable throughout the Late Pleistocene-Holocene. Alternatively, this sedimentology could reflect the weatherability and erodibility of the catchment geology. By applying paleomagnetism work we aim to better understand climate dynamics in the late Pleistocene/early Holocene of the Cordillera Central and utilize the data for comparison of Huaylillas and other regional paleoclimate records. Through understanding the behavior of these glacial pulses and how to interpret them as an indicator of paleoclimate, we can further interpret regional climate variability and the drivers of glacial extent through time. It is important we continue to collect these records due to their dual use as recorders of glacial patterns, as they record P-E balance during warm periods and glacial extent during cold periods.