56 Paleolimnological Records of Climate and Environmental Change (Posters)

Sunday, 22 March 2020
8:00 AM - 12:00 PM
Lake Anne

A LATE-QUATERNARY RECORD OF TERRESTRIAL AND AQUATIC ECOSYSTEM VARIABILITY DEVELOPED USING MULTI-PROXY ANALYSIS OF NORTHEAST PENNSYLVANIA LAKE SEDIMENTS

Paper number: 56-9
Program: Theme Sessions
Time: 8:00 AM – 12:00 PM

Authors

Abstract

High-resolution paleoclimate records spanning the late-Quaternary from the northeast Pennsylvania (NEPA) ice margin are relatively rare, despite the abundance of natural lakes in the region. Previous research using sediments from Nuangola Lake (41.159º N, 75.974º W, 356 m ASL), a glacial lake located 12 km north of the terminal moraine of the last ice age, found the lake contains a continuous archive of late-Quaternary paleoclimate variability. Sedimentary facies analysis revealed the record consists of basal glaciolacustrine (varved) sediments, overlain by transitional minerogenic sediments, and capped by organic rich post glacial sediments. In this expanded study of the sediment record, we collected additional overlapping sediment cores to ensure complete recovery of the sequence. Furthermore, we provide better age model development, through radiocarbon dates on terrestrial macrofossils and cryptotephra deposits. We measured visible reflectance to estimate chlorophyll-a content and biogenic silica in order to document terrestrial and aquatic ecosystem variability. Our preliminary results show contrasting patterns of inferred terrestrial and aquatic ecosystem variability across the late Pleistocene to Holocene transition, which likely reflects differences in the sensitivity of proxies at recording environmental changes. We will discuss our results in the context of other local to regional paleoclimate records to explore the underlying climate forcings or mechanisms that could help explain the observed changes in the Nuangola Lake record.

Geological Society of America Abstracts with Programs. Vol. 52, No. 2

doi: 10.1130/abs/2020SE-344714

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