AbstractsChemistry

A LATE GLACIAL-EARLY HOLOCENE PALEOCLIMATE SIGNAL FROM THE OSTRACODE RECORD OF TWIN PONDS, VERMONT

by Kevin Engle




Institution: Kent State University
Department: College of Arts and Sciences / Department of Geology
Degree: MS
Year: 2015
Keywords: Geology; Paleoclimate Science; Paleoecology; Geochemistry; Ostracodes, Paleoclimate, Micropaleontology, Paleolimnology, Geology, Oxygen Isotopes, Statistical Analysis
Record ID: 2057939
Full text PDF: http://rave.ohiolink.edu/etdc/view?acc_num=kent1428255554


Abstract

During the fall of 2012, a sediment core was collected from Twin Ponds Lake in Brookfield, Vermont. Twin Ponds Lake is located in central Vermont with the surrounding rocks being Silurian to Devonian age phyllite and limestone. This research is focusing on using isotopic analysis of ostracodes from the core in order to assist in climatic reconstruction of the region from the Late Glacial to the Early Holocene. The ostracodes are part of a multi-university effort to analyze the core: additional research is focusing on pollen, loss on ignition, charcoal and bulk carbonate analysis of the core. New England is very sensitive to climate change so isotopic analysis of the carbonate in the ostracode carapaces along with the bulk carbonate analysis will provide a very detailed account of the changing climate of the region. The sediment record of this core ranges in time from the Late Glacial throughout the Holocene but the most detailed records are found from just before and after the Younger Dryas. This study is important for the ostracode record, being the first Holocene ostracode record for New England outside of Lake Champlain. This record shows the easternmost distribution of the species from the mid-continent such as Candona ohioensis, Candona paraohioensis and Candona candida. Cyclocypris globosa is a cold tolerant species, most commonly found in the Yukon. Its presence towards the bottom of the core is a clear Younger Dryas signal. Additionally, the presence and abundance of certain species of ostracodes are good indicators of a rising and falling lake level.