253-5 Conodonts and the Frasnian-Famennian boundary (Upper Devonian) along Wiscoy Creek – type Wiscoy Formation, western New York State

Session: Conodonts from North America and Beyond - Honoring the Career of Dr. James E. Barrick

Presenting Author:

Authors:

Abstract:

The Frasnian-Famennian boundary in the offshore mudstones of the upper Hanover Formation, which marks one of the major extinctions in the Phanerozoic, is clearly demarcated in western New York State by conodonts.  The Dunkirk Formation, a prominent and widely developed black shale equivalent to the lower Huron Shale of the Ohio Formation, lower Gassaway Member of the Chattanooga Formation, and Morgan Trail Member of the New Albany Formation, represents the major flooding of the IIe transgression of Johnson et al. (1985) in the lower Famennian.  The Wiscoy Formation, the more nearshore lateral equivalent of the Hanover Formation, which consists primarily of gray silty shales, siltstones, very fine sandstones, as well as concretion intervals and thin silty black shales, yielded a diverse and cosmopolitan conodont fauna that includes Ancyrodella curvata, Ancyrodella hamata, Palmatolepis bogartensis, Palmatolepis boogaardi, Palmatolepis brevis, Palmatolepis linguiformis, Palmatolepis winchelli, Polygnathus decorosus, and Polygnathus webbi in Frasnian strata and Palmatolepis delicatula, Plamatolepis subperlobata, and Palmatolepis triangularis in Famennian strata. Small brachiopods, bivalves, auloporid corals, crinoids, and ostracodes were also recovered across the boundary interval.  The boundary horizon is resolved to 10 cm, within primarily black shale strata, that lie above a siltstone bed and three-meter-thick black shale bed, which is stratigraphically lower than the Dunkirk Formation.

Geological Society of America Abstracts with Program. Vol. 57, No. 6, 2025

doi: 10.1130/abs/2025AM-7685

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