PROPOSED REVISION AND CORRELATION OF UPPERMOST SILURIAN STRATIGRAPHY IN SOUTHEASTERN NEW YORK AND NORTHWESTERN NEW JERSEY

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 the 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 (Duttonville, Whiteport and Mashipacong mbrs.), 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 (Wilbur, Rosendale, Glasco, Whiteport mbrs.), and Manlius formations. Between Accord and the NY-NJ line there also exists a poorly-know unit called the Wawarsing Limestone, found only in the subsurface, that sits below the High Falls/Poxono Island formations (Epstein, 1993). Perhaps most confusing are the members of the Rondout Fm. between NJ and NY, especially since 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 extend the Poxono Island Fm. north to the area of Kingston to include all of the strata between the Shawangunk Fm. and the Rondout Fm., with various preexisting units in this interval transferred to the member level. 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 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.