Hostname: page-component-cd9895bd7-hc48f Total loading time: 0 Render date: 2024-12-26T21:10:25.220Z Has data issue: false hasContentIssue false

Fossil communities of the upper Trenton Group (Ordovician) of New York State

Published online by Cambridge University Press:  14 July 2015

Robert Titus*
Affiliation:
Department of Geology, Hartwick College, Oneonta, New York 13820

Abstract

During the late Trentonian the New York State region experienced gentle crustal subsidence which preceded the onset of the Hudson Valley phase of the Taconic Orogeny. The lower and middle Steuben Limestone represents several shallow-water facies: a protected shoal, a wave dissipation zone and a shallow shelf. Overlying strata of the upper Steuben and the Hillier limestones represent progressively deeper water facies. After a short period of uplift, which produced a minor unconformity, black shales began to bury the Trenton carbonate platform.

Three fossil communities are found in the upper Trenton Group. Each had been present on the Trenton bank since it first formed. The Liospira Community existed on the shallow protected shoal facies of the Steuben Limestone. Its assemblages are dominated by brachiopods, gastropods, bryozoans, and crinoids. The Encrinurus Community was found in the wave dissipation zone and on the shelf facies. This diverse community was dominated by brachiopods, bryozoans, and crinoids. The Trematis Community is found in the deeper shelf deposits of the Hillier Limestone. It was a very heterogeneous community with brachiopods, crinoids, gastropods, trilobites, and conodonts all represented.

These communities have now been traced through a minimum of eight million years of their history and it is now possible to evaluate their patterns of community evolution. At the species level these communities were quite changeable. Between 45% and 55% of the species which were present in the lower Trenton Group were replaced by the late Trentonian. Despite this changeover, the communities maintained a remarkably familiar look because there was great stability at higher taxonomic levels and the same proportions of brachiopods, bryozoans, crinoids, etc., were maintained throughout the Trentonian. Community trophic group structure also seems to have been quite stable throughout the Trentonian. If these patterns are representative, then these invertebrate communities appear to be genuinely stable entities. Evolution changes the cast of characters but the play is the same!

Type
Research Article
Copyright
Copyright © The Paleontological Society 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Alexander, R. R. 1975. Phenotypic lability of the brachiopod Rafinesquina alternata (Ordovician) and its correlation with sedimentologic regime. Journal of Paleontology, 49:607618.Google Scholar
Chapple, W. M. 1973. Taconic Orogeny: abortive subduction of the North American continental plate. Geological Society of America, Abstracts with Programs, 5:573.Google Scholar
Cisne, J. L., Karig, D. E., Rabe, B. D. and Hay, B. J. 1982. Topography and tectonics of the Taconic outer trench slope as revealed through gradient analysis of fossil assemblages. Lethaia, 15:229246.CrossRefGoogle Scholar
Cisne, J. L. and Rabe, B. D. 1978. Coenocorrelation: gradient analysis of fossil communities and its applications in stratigraphy. Lethaia, 11:341374.CrossRefGoogle Scholar
Fisher, D. W. 1977. Correlations of the Hadrynian, Cambrian and Ordovician rocks in New York State. New York State Museum Map and Chart Series 25, 75 p.Google Scholar
Fisher, D. W. 1979. Folding in the foreland, Middle Ordovician Dolgeville facies, Mohawk Valley, New York. Geology, 7:455459.2.0.CO;2>CrossRefGoogle Scholar
Kay, G. M. 1933. The Ordovician Trenton Group in northwestern New York, stratigraphy of the lower and upper limestone formations. American Journal of Science, 5th series, 26:115.Google Scholar
Kay, G. M. 1937. Stratigraphy of the Trenton Group. Geological Society of America Bulletin, 48:233302.CrossRefGoogle Scholar
Kay, G. M. 1943. Mohawkian stratigraphy of West Canada Creek, New York. American Journal of Science, 241:597606.CrossRefGoogle Scholar
Kay, G. M. 1951. North American Geosynclines. Geological Society of America Memoir 48, 143 p.Google Scholar
Kay, G. M. 1953. Geology of the Utica Quadrangle, New York. New York State Museum Bulletin 347, 126 p.Google Scholar
Rodgers, J. 1971. The Taconic Orogeny. Geological Society of America Bulletin, 82:11411178.CrossRefGoogle Scholar
Schopf, T. J. M. 1966. Conodonts of the Trenton Group (Ordovician) in New York, southern Ontario and Quebec. New York State Museum Science Bulletin 405, 105 p.Google Scholar
Titus, R. 1982. Fossil communities of the middle Trenton Group (Ordovician) of New York State. Journal of Paleontology, 57:477485.Google Scholar
Titus, R. and Cameron, B. 1976. Fossil communities of the lower Trenton Group (Middle Ordovician) of central and northwestern New York State. Journal of Paleontology, 50:12091225.Google Scholar