The Provenance of Glacial Till and Beach Sand in the Cape Cod Area

The provenance of glacial till deposited in the Cape Cod area can be used to more accurately characterize the previous extent and flow of the Laurentide Ice Sheet (LIS). In this study, we collected samples of till, aeolian sands, and beach sands from 12 different locations that represent both the Cape Cod lobe and the Buzzards Bay lobe of the LIS. The samples for each respective lobe were collected at a variety of northern and southern locations, therefore, the provenance of the samples represent a time sequence for both lobes. Samples collected from Marthas Vineyard record the LIS at its oldest and maximum extent during the LGM period, and samples collected from the mainland of Cape Cod represent younger deposits from the each of the lobes. We will determine the provenance of the till by analyzing the grain size and chemical composition, as well as dating detrital zircon found in the till. We will measure the grain size using a Malvern Mastersizer 3000, determine the bulk geochemistry using Niton XRF Analyzer, and determine age using U/Pb dating on detrital zircons. We aim to examine the degree of similarity between the source areas of the two lobes. Further, we would like to determine the provenance of samples from areas in the region that have not been typically assigned to either lobe in order to determine how these areas can be related to our current understanding of the lobes. Additionally, our collection of beach and Aeolian sands will allow us to compare the provenance data between samples in order to determine the degree to which transport processes alter the provenance signal of the samples. Our analysis will provide a new degree of background for glacial movement in the region. This update to our understanding of the past glacial fluctuations will aid current conversations regarding the environmental change that we are experiencing in the current day.