GSA Connects 2021 in Portland, Oregon

Paper No. 93-9
Presentation Time: 9:00 AM-1:00 PM


ABBATI, Emily1, GERSTLER, Kaitlyn1, ROSE, Griffin1, GAHLOD, Shekhar2, MORGAN, Justin2, RIOS, Pablo2, STREET, Christian2, MICHELSON, Andrew2 and WITTMER, Jacalyn1, (1)Geological Sciences, SUNY Geneseo, 1 College Circle, Geneseo, NY 14454, (2)Science Department, SUNY Maritime College, 6 Pennyfield Ave, Bronx, NY 10465-4127

The geohistorical record yields valuable data on past environmental and ecological changes that can be used as tools for conservation and restoration/remediation. This study sets out to establish a pre-European colonization baseline for the finger lake communities in western New York, specifically, Conesus Lake. Conesus Lake was selected because it has been rated as a mesotrophic lake that has been undergoing continual remediation and monitoring since the introduction of invasive taxa and harmful cyano-algal blooms in the mid-1990s. Piston and bolivia cores were collected from the south basin of Conesus lake to evaluate the sedimentology and its influence on the lake ecosystem. A piston core of the deep south basin was collected at 17 meters in depth and resulted in 121 cm of cored sediments. Both piston and bolivia cores of the shallow south basin were collected near the lake inlet at 1.8 meters in depth resulting in a composite core of 151 cm. Both cores were split, imaged, and analyzed for both magnetic susceptibility and XRF using a multi-sensor core logger. Sediments were subsampled and processed for diatoms and total organic carbon at regular six cm intervals.

Preliminary results indicate a significant sedimentological change towards the recent in which organic content spikes and the grain size coarsens towards the upper 40-50 cm. In the south basin shallow cores, the amount of macroinvertebrate skeletal components increased near the core top. Comparisons between the shallow and deep south basin cores reflect the constrained sediment transport and delivery of the narrow watershed. The abundance of diatoms in both deep and shallow cores were variable with well-preserved planktic diatoms dominating the deep core and fragmented, partially dissolved planktic and benthic diatoms recovered from the shallow core. Both cores, shallow and deep, display different rates of sedimentation based on the first appearance of zebra mussels, which agrees with the preservation of their associated diatom communities.