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The AAPG/Datapages Combined Publications Database

AAPG Bulletin


Volume: 63 (1979)

Issue: 9. (September)

First Page: 1590

Last Page: 1590

Title: Upper Niagaran and Lower Cayugan Stratigraphy and Depositional Environments of Central Appalachian Basin: ABSTRACT

Author(s): Albert J. Warner

Article Type: Meeting abstract


Data from geophysical logs and sample descriptions of 677 wells were used to prepare nine cross sections and 38 maps that illustrate upper Niagaran and lower Cayugan stratigraphic relations and environmental constructions within the central Appalachian basin of New York, Pennsylvania, West Virginia,Ohio, Maryland, and Ontario. Ten basin-wide stratigraphic intervals (genetic sequences of strata) were correlated and mapped on the basis of interpreted time-stratigraphic markers. Fourteen lithofacies, which are repeated in several of these intervals, were recognized in the subsurface on the basis of characteristic radioactivity-log patterns supplemented with sample descriptions. Four of the lithofacies occur in dolomite, either with or without sulfates, three in limestones an shales, and two each in halite and sandstone.

Stratigraphic and lithofacies analysis reveals that the Lockport Formation in the northern and western parts of the basin is a rock-stratigraphic unit consisting of reefal, shallow-water, and carbonate tidal-flat facies that undergoes a complete gradation eastward into transitional marine and continental clastics within the first five intervals of the study. The remaining intervals were dominated by restricted evaporite basins, carbonate mud flats, and carbonate-sulfate mud flats (sabkhas) over the northern and western parts of the basin, whereas less restricted shallow-marine to intertidal environments were present in the southeast.

Detailed correlations indicate several inconsistencies in past correlations of Upper Silurian strata, most notably the miscorrelation of the Williamsport and Newburg sandstones that has resulted in considerable confusion in nomenclature and correlation in the Silurian of West Virginia.

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