28 Interstate Stratigraphic Correlation: A Practical Geology Session (Posters)

Primarily a hands-on display of core and samples with posters, and talks, to facilitate interstate correlation. Concepts covered are related to interstate correlation problems in stratigraphy—mapping, source rocks for REE minerals, geochronology, and regolith.

Tuesday, 10 March 2026
9:00 AM - 5:00 PM
RCC, Lower Level Hall

Early Pleistocene Depositional Sequences in the Context of Major Landform Elements: North Carolina - Virginia Interstate Correlation

Paper number: 28-1
Program: Technical Sessions
Time: 9:15 AM – 9:30 AM

Authors

Abstract

NCGS participated in a multi-year project with Virginia Energy (VA) to collect cores and exchange stratigraphic information for interstate correlation. Here, NCGS presents examples of Early Pleistocene depositional sequences in cores that occur in updip areas of the NC/VA Coastal Plain.  Principal targets were units defined in Virginia—the Bacons Castle Formation and the informal Cold Harbor Formation.  The main questions are: What is the stratigraphic relationship between the Cold Harbor and the Bacons Castle? Does the Cold Harbor underlie or overlie the Bacons Castle?  How do the Chowan River and Yorktown units interface with these presumably younger units? Cores are provided for review.

Graphic logs for select cores in NC and VA were chosen to represent the stratigraphy beneath several major landform elements in the updip Coastal Plain.  Here several Pliocene (?) to Early Pleistocene paleoshorelines converge in the Fall Zone.  In NC, these are the Kenly, Wilson Mills and Coats/Orangeburg ‘scarps’ with respective toe elevations of 46 m, 75 m and 84 m.  A toe elevation may mark the toe of the paleoshoreface not the sea level highstand position.  The cores shown here were drilled at surface elevations between 74 and 38 m and detail the stratigraphy of the Coharie and Sunderland terraces. In NC, the Kenly paleoshoreline separates the two terraces.

Mapping in VA indicates that the Bacons Castle surficially underlies terraces with surface elevations of ~ 35-51.8 m (115-170 ft)—the Sunderland and eastern part of the Coharie.  The informal Cold Harbor may occur at higher elevations surficially.  In NC, a well-constrained cross section through the Kenly scarp shows a clear disconnect between surficial marine and coastal depositional sequences deposited west and east of this shoreline.  East is the Bacons Castle; but west is a thicker more complicated sand-rich depositional sequence (Cold Harbor? equivalent).   In VA, the stratigraphic relationships appear similar based on the current data set, but cores are widely spaced.

A hypothesis is that the Kenly shoreline marks a transition from normal to forced regression.  West of the Kenly are thick shoreline sands, in part, representing the highstand systems tract (HSST) associated with the Kenly shoreline.  East of the Kenly is the falling stage systems tract (FSST) (the Bacons Castle).  The HSST should be separated from the FSST as formal stratigraphic units.

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

doi: 10.1130/abs/2026SE-411758

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