Ludlowville Formation Explained

Ludlowville Formation
Type:Formation
Age:Devonian
Prilithology:Shale
Otherlithology:Limestone, Mudstone, Claystone
Region:New York
Pennsylvania
Ohio
Country:United States
Unitof:Hamilton Group
Subunits:
  • Owasco Shale
  • Jaycox Formation
  • Spafford Shale
  • Wanakah Shale
  • Ledyard Shale
  • Otisco Shale
  • Centerfield Limestone
Underlies:Moscow Formation
Overlies:Skaneateles Formation
Map:Ludlowville Map.jpg

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

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]

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.

Notes and References

  1. Web site: BRETT . CARLTON E . 1986 . SEDIMENTARY CYCLES AND LATERAL FACIES GRADIENTS ACROSS A MIDDLE DEVONIAN SHELF-TO-BASIN RAMP LUDLOWVILLE FORMATION, CAYUGA BASIN . NYSGA Online.
  2. Web site: Craft . Jesse L. . CORRELATION OF THE FALKIRK AND FIDDLERS GREEN MEMBER OF THE BERTIE FORMATION . 1 Dec 2023 . Otto's Website (ottohmuller.com).
  3. Web site: 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 . 1 December 2023 . webcentral.uc.edu.
  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 . 10.1017/s0022336000042256 . 1990JPal...64...79G . 133456873 . 0022-3360.
  5. Cooper . G. A. . 1934-01-01 . Stratigraphy of the Hamilton Group, eastern New York . American Journal of Science . s5-27 . 157 . 1–12 . 10.2475/ajs.s5-27.157.1 . 1934AmJS...27....1C . 0002-9599.