Northeastern Section - 56th Annual Meeting - 2021

Paper No. 8-2
Presentation Time: 1:55 PM


BARTHOLOMEW, Alex J., Department of Geology, SUNY New Paltz, 1 Hawk Drive, New Paltz, NY 12561

The uppermost Silurian stratigraphy of southeastern NY (Port Jervis to Kingston) and northwestern NJ (PA to NY), though more than adequately described, remains confusing and altogether rather poorly understood in relation to the details of stratigraphic nomenclature and correlation. Much of the confusion and miscorrelation stems from a paucity of exposure and relatively rapid facies changes between scattered outcrops. Recent examination of existing outcrops and reevaluation of historic and modern literature, with a focus upon setting the stratigraphic units into a broader regional framework, has resulted in the opportunity to revise stratigraphic nomenclature to reflect a better understanding of the relationships between the various units through this interval.

In northwestern NJ and southeastern NY, the stratigraphic sequence for this interval consists of, from bottom to top, the Poxono Island, Bossardville, Decker Ferry, Rondout, and Manlius formations. In the area between Accord and Kingston NY, the stratigraphic sequence consists of, from bottom to top, the High Falls, Binnewater, Rondout, and Manlius formations. Confusing stratigraphic issues include the members of the Rondout Fm. between NJ and NY, where strata traditionally referred to the lowermost Manlius Fm. in the Hudson Valley area of NY are included within the uppermost Mashipacong Mbr. in NJ.

Herein it is proposed to geographically extend the term Poxono Island Fm. north to the vicinity of Kingston to include all of the strata between the Shawangunk Fm. and the Rondout Fm., with various preexisting formation-level units in this interval transferred to the member level within the Poxono Island Fm. This is proposed in order to redefine the Poxono Island Formation as an allostratigraphic unit comprising the facies mosaic of time-equivalent units between the Shawangunk and Rondout formations. Additionally, it is proposed to transfer the uppermost strata of the Mashipacong Mbr. to the Manlius Fm. and to apply the name Mashipacong only to the lowermost strata of the Manlius Fm. in NJ and extend it north into NY. Further discussion of stratigraphic revision within the lowermost Manlius Fm. and regional correlation will be included. It is hoped the revisions suggested herein will act to simplify, not further confound, our understanding of this interval.