The Trenton Limestone--Utica Shale succession: Depositional events in a Middle to Late Ordovician foreland basin setting, New York State
- S.U.N.Y. Fredonia, Fredonia, NY (United States). Dept. of Geosciences
- Univ. of Rochester, Rochester, NY (United States). Dept. of Geological Sciences
The Trenton Limestone to Utica Shale succession, northeast of Utica, N.Y. is still enigmatic with regard to its internal stratigraphy and inferred sequence of depositional and tectonic events. The middle Trenton can be subdivided into at least six small scale depositional sequences. Each is marked by a thin, sharply-based nodular wacke- to packstone interval (transgressive systems tract) and is separated from overlying dark shales and calcilutites (highstand systems tract) by surfaces of sediment starvation. Overall, these sequences record the progressive northwestward retreat of shelf facies with concurrent sediment-starvation and stratigraphic-condensation of equivalent slope facies in the basin. Furthermore, these sequence-scale cycles nest parasequence-scale cycles. Using event horizons, submarine discontinuities and sedimentary cycles as lithochronostratigraphic markers, the present authors recognize that: (1) middle Trenton transgressive deposits pass basinward (eastward) into condensed bioclastic facies; geographically widespread facies of the upper Dolgeville correspond to early highstand with establishment of dysoxic conditions, (2) the Utica Shale (sensu strictu) appears to be separated from the Trenton Limestone and Trenton-equivalent strata (Dolgeville facies) by a widespread unconformity, and (3) an unconformity separates lower to middle Utica Shale from upper Utica Shale. The two unconformities apparently merge east on Trenton Falls such that upper Utica strata rest unconformably on Steuben strata (upper Trenton). This merged unconformity surface is regionally extensive, beveling successively older Trenton strata in a southeastward direction.
- OSTI ID:
- 5688852
- Report Number(s):
- CONF-921058-; CODEN: GAAPBC
- Journal Information:
- Geological Society of America, Abstracts with Programs; (United States), Vol. 24:7; Conference: 1992 annual meeting of the Geological Society of America (GSA), Cincinnati, OH (United States), 26-29 Oct 1992; ISSN 0016-7592
- Country of Publication:
- United States
- Language:
- English
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