Conodonts were extracted from three limestone units in westcentral Indiana: the Silverwood Limestone Member of the Staunton Formation; the Universal Limestone Member of the Dugger Formation; and from a new unit, the informally named Salt Creek limestone lens (Dagger Formation). Identified conodonts include: Adetognathus gigantus (Gunnell), 1933; Adetognathus lautus (Gunsell), 1933; Idiognathodus delicatus Gunnell, 1931; Idiognathodus sinuosis Ellison and Graves, 1941; Neognathodus bassleri bassleri (Harris and Hollingsworth), 1933; Spathognathodus coloradoensis Murray and Chronic, 1965; S athognathodus minutes Ellison, 1941; Spathognathodus orphanus Merrill, 1973; Streptognathodus holmesi Gunnell, 1933; and Streptognathodus minatus Gunnell, 1933.The presence of the genus Streptognathodus in the Salt Creek limestone lens supports the hypothesis that streptognathodid numbers increase in rocks of mid-Desmoinesian age or younger. The scarcity of conodonts in the Universal Limestone Member may ba attributed to storm-related deposition of unusually large quantities of carbonate sediments, effectively diluting the conodont population, followed by infaunal reworking of these sediments during a period of little or no deposition.The occurrence of conodonts establishes that the Silverwood limestone Member is early to middle Desmoinesian in age, the Universal Limestone Member is middle to late Desmoinesian in age, and that the newly discovered Salt Creek limestone lens is middle to late Desmoinesian in age.
| Identifer | oai:union.ndltd.org:BSU/oai:cardinalscholar.bsu.edu:handle/182633 |
| Date | January 1982 |
| Creators | Stanley, Sarah G. |
| Contributors | Orr, R. William |
| Source Sets | Ball State University |
| Detected Language | English |
| Format | vii, 77 leaves, 3 leaves of plates : ill. ; 28 cm. |
| Source | Virtual Press |
| Coverage | n-us-in |
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