Bald Mountain Limestone, New York: New Facts and Interpretations Relative to Taconic Geology

Sanders, John; Platt, Lucian B.; Powers, R. W

doi:10.1130/0016-7606(1961)72[485:bmlnyn]2.0.co;2

Cited by 15 publications

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“…-Cushing and Ruedemann (1914) listed cephalopod localities in a giant (8.4 km long, 0.8 km wide), north-south-trending carbonate block that lies under the Taconic allochthon in southern Washington County. This tectonic sliver, which they named the "Bald Mountain Limestone," was ripped from the east Laurentian platform during the Taconic orogeny (e.g., Zen, 1964), and includes lithologies referable to a number of Beekmantown Group formations (Sanders et al, 1961). Cushing and Ruedemann (1914, p. 77) listed Cameroceras brainerdi (Whitfield) and Cyrtoceras confertissum Whitfield from the Bald Mountain quarry at the north end of the block-specimens not found in the NYSM collection and not recollected during field work in the quarry.…”

Section: Materials Studied-threementioning

confidence: 99%

Cephalopods and paleoenvironments of the Fort Cassin Formation (upper Lower Ordovician), eastern New York and adjacent Vermont

Kröger

Landing

2009

J. Paleontol.

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The dramatic late Early Ordovician radiation of cephalopods on tropical paleocontinents is illustrated by the diverse fauna (21 genera, 30 species) of the Fort Cassin Formation (Floian and lower Blackhillsian Stage) in northeast Laurentia. Cephalopods occur through the thin (ca. 30–65 m) depositional sequence of the Fort Cassin but are most common and diverse in mollusk-rich, trilobite-poor parts of the formation that characterize the thrombolite-bearing intervals in the shoaling part of the highstand systems tract. This lithofacies-biofacies linkage persists from the Tribes Hill and Rochdale Formations (lower and lower upper Tremadocian, and upper Skullrockian and Stairsian Stages, respectively), and suggests that the Early Ordovician radiations of cephalopods took place in shallow-marine, thrombolite reef facies of tropical carbonate platforms. These habitats differed strongly from the near-shore, peritidal habitats of the older Cambrian evolutionary radiation. Genus-level diversity and absolute abundance changed little through the Skullrockian-Blackhillsian, but morphologic diversity and body size increased dramatically by the late Early Ordovician. The morphological diversification suggests cephalopods diversified into a wider variety of macropredators and more complex late Early Ordovician ecosystems. Anrangeroceras whitehallense n. gen. and n. sp. is proposed. The following are emended: the Protocycloceratidae, Centrotarphyceras and C. seelyi, Protocycloceras and P. lamarcki, and Rudolfoceras cornuoryx. The following are indeterminate and abandoned: Baltoceras? pusillum Ruedemann, 1906; Comeroceras annuliferum Flower, 1941; Cyptendoceras whitfieldi Ulrich et al., 1944; Endoceras? champlainense Ruedemann, 1906; Wolungoceras valcourense Flower, 1964. Beekmanoceras Ulrich and Foerste, 1936 is a gastropod.

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Section: Materials Studied-threementioning

confidence: 99%