Ludlowville Formation

The Ludlowville Formation is a geologic formation in New York, Ohio and Pennsylvania. It dates to the Devonian period.^[1]

Ludlowville Formation
Stratigraphic range: Devonian
Monodechenella macrocephala, Houston Museum of Natural Science
Type	Formation
Unit of	Hamilton Group
Sub-units	Owasco Shale Jaycox Formation Spafford Shale Wanakah Shale Ledyard Shale Otisco Shale Centerfield Limestone
Underlies	Moscow Formation
Overlies	Skaneateles Formation
Lithology
Primary	Shale
Other	Limestone, Mudstone, Claystone
Location
Region	New York Pennsylvania Ohio
Country	United States
Geographic extent of the Ludlowville Formation

Subunits

Owasco

The Owasco is a thin distinct silty unit. It has sharp distinct boundaries at its top and base. It is flaggy, locally fossiliferous and is displays cross bedding in some locations. The upper contact maybe a diastem, rather than an erosional disconformity. This unit is fairly thin only 1-2' thick in outcrops. It thickens westward.^[2]

Fossils

The brachiopod AIlanella tullius is one of the fossils the Owasco is noted for.

Jaycox

The Jaycox Formation is a geologic formation in New York. It preserves fossils dating back to the Devonian period.

The basial Jaycox contains the Hills Gulch bed, a fossiliferous bed with corals and shells, as well as megaburrows at its basial contact. The Hills Gulch is a calcareous siltstone.^[3]

Spafford

Wanakah

Centerfield Limestone

The Centerfield Limestone is a geologic formation in New York, and Pennsylvania. It dates back to the Devonian period. It is the lowest member of the Ludlowville Formation and it overlies the Skaneateles Formation.^[4][5] The Peppermill Gulf bed is included within the Centerfield Lime. The unit was named by Smith (1930)

Fossils

This Limestone unit contains fossils of crinoids, rugosa, bivalvia, trilobites and brachiopods. This unit also contains several corals including; Eridophyllum and Heliophyllum hali.

References

1. BRETT, CARLTON E (1986). "SEDIMENTARY CYCLES AND LATERAL FACIES GRADIENTS ACROSS A MIDDLE DEVONIAN SHELF-TO-BASIN RAMP LUDLOWVILLE FORMATION, CAYUGA BASIN" (PDF). NYSGA Online.
2. Craft, Jesse L. "CORRELATION OF THE FALKIRK AND FIDDLERS GREEN MEMBER OF THE BERTIE FORMATION" (PDF). Otto's Website (ottohmuller.com). Retrieved 1 Dec 2023.
3. Bartholomew, Alexander J; Brett, Carlton E.; DeSantis, Michael; Baird, Gordon C.; Tsujita, Cameron. "SEQUENCE STRATIGRAPHY OF THE MIDDLE DEVONIAN AT THE BORDER OF THE MICHIGAN BASIN: CORRELATIONS WITH NEW YORK AND IMPLICATIONS FOR SEA-LEVEL CHANGE AND PALEOGEOGRAPHY" (PDF). webcentral.uc.edu. Retrieved 1 December 2023.
4. Goldman, Daniel; Mitchell, Charles E. (1990). "Morphology, systematics, and evolution of Middle Devonian Ambocoeliidae (Brachiopoda), western New York". Journal of Paleontology. 64 (1): 79–99. Bibcode:1990JPal...64...79G. doi:10.1017/s0022336000042256. ISSN 0022-3360. S2CID 133456873.
5. Cooper, G. A. (1934-01-01). "Stratigraphy of the Hamilton Group, eastern New York". American Journal of Science. s5-27 (157): 1–12. Bibcode:1934AmJS...27....1C. doi:10.2475/ajs.s5-27.157.1. ISSN 0002-9599.