Abstract: Biogenic Structures and Their Paleoenvironmental Distribution in Tully Clastic Correlatives (Devonian), East-Central New York

Molly Fritz Miller

The clastic equivalents of the Devonian Tully Formation and associated rocks, which crop out in a band approximately 100 mi (30 km) long in east-central New York, were deposited in alluvial to offshore environments of the Catskill delta complex. The moderately diverse ichnofauna consists of several types of vertical burrows including probable large sea anemone burrows and small Arenicolites, filled and unfilled horizontal burrows ranging from 0.3 to 6 cm in diameter, and several Zoophycos-like structures as well as forms of the incholgenera Bifungites, Cruziana, Teichichnus, and Isopodichnus. Most of the trace fossils are in rocks deposited under a range of environmental conditions; their distribution is not obviously related to environment or substrate texture. Exception include a small form of Spirophyton, which is restricted to the alluvial and tidal facies, and Arenicolites (resembling modern spinoid burrows), and the large sea anemone(?) burrows which are present only in rocks deposited in tidal and nearshore environments. There are two possible explanations for the broad lateral distribution of the biogenic structures: the wide ranges may reflect the very gradual environmental change over a large area, or the continental but varied influx of sediment may have inhibited development of stable, environmentally distinct ichnocoenoses.

AAPG Search and Discovery Article #90968©1977 AAPG-SEPM Annual Convention and Exhibition, Washington, DC