23-20 Cretaceous Gravels or Glacial Diamictites? The Case of Dover Road and Lighthouse Cliff in the Jackson Purchase Region of Kentucky

Session: Paleontology of North America (Posters)

Poster Booth No.: 20

Presenting Author:

Maeve McCarty

Authors:

McCarty, Maeve M.¹, Gray, Kyndra M.², Jack, Asher D.³, Lung, Ethan R.⁴, Park, Beau A.⁵, Devera, Joe⁶, Beck, Ennis Glynn⁷, Greb, Stephen F.⁸, O'Keefe, Jennifer M.K.⁹

(1) Department of Engineering Sciences, Morehead State University, Morehead, KY, USA, (2) Craft Academy for Excellence in Science and Mathematics, Morehead State University, Morehead, KY, USA, (3) Department of Engineering Sciences, Morehead State University, Morehead, KY, USA, (4) Engineering Sciences, Morehead State University, Morehead, KY, , (5) Department of Engineering Sciences, Morehead State University, Morehead, KY, USA, (6) ISGS, Carterville, IL, , (7) Kentucky Geological Survey, Henderson, KY, , (8) Kentucky Geological Survey, Lexington, KY, , (9) Department of Engineering Sciences, Morehead State University, Morehead, KY, USA,

Abstract:

The Mississippi Embayment Mapping-Biostratigraphy (MEMBi) Project aims to check historical palynostratigraphic controls to confirm age assignment of rock units used in surficial and sub-surface mapping throughout the Northern Mississippi Embayment. The early stages of the project have focused on two end members of the units found in this region: upper Cretaceous and Eocene units. In Kentucky, it is often difficult to differentiate Cretaceous clay-rich gravel deposits from those deposited later using lithostratigraphy alone, and palynostratigraphy is rarely applied to gravel deposits due to grain-size effects and the risk of wash down of younger palynomorphs into porous sediments. However, examination of clay lenses within larger gravel deposits is possible. Dover Road and Lighthouse Cliff are classic examples of quartz-pebble and cobble conglomerates that form readily accessible resistant ledges in the region. Their purported age is unclear from existing geological maps; the designation of “Cretaceous” and “Quaternary” for gravel deposits seems to be arbitrary. Low-acid palynological processing methods were used to obtain the full suite of palynomorphs contained in clay lenses within the gravels. While sparse, the suite is clearly not representative of Cretaceous plants and suggests that the gravels in both localities are Quaternary diamictites.

Geological Society of America Abstracts with Programs. Vol. 58, No. 1, 2026

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