The Ludlowville Formation is a

geologic formation A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics ( lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock exp ...

New York New York most commonly refers to: * New York (state), a state in the northeastern United States * New York City, the most populous city in the United States, located in the state of New York New York may also refer to: Places United Kingdom * ...

, Ohio and Pennsylvania. It dates to the

Devonian The Devonian ( ) is a period (geology), geologic period and system (stratigraphy), system of the Paleozoic era (geology), era during the Phanerozoic eon (geology), eon, spanning 60.3 million years from the end of the preceding Silurian per ...

period Period may refer to: Common uses * Period (punctuation) * Era, a length or span of time *Menstruation, commonly referred to as a "period" Arts, entertainment, and media * Period (music), a concept in musical composition * Periodic sentence (o ...

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 In geology, a diastem is a short interruption in sedimentation with little or no erosion. They can also be described as very short unconformities (more precisely as very short paraconformities). In 1917, Joseph Barrell estimated the rate of deposi ...

, rather than an erosional disconformity. This unit is fairly thin only 1-2' thick in outcrops. It thickens westward.

Fossils

The

brachiopod Brachiopods (), phylum (biology), phylum Brachiopoda, are a phylum of animals that have hard "valves" (shells) on the upper and lower surfaces, unlike the left and right arrangement in bivalve molluscs. Brachiopod valves are hinged at the rear e ...

''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.

Spafford

Wanakah

Centerfield Limestone

The Centerfield Limestone is a

, and

Pennsylvania Pennsylvania, officially the Commonwealth of Pennsylvania, is a U.S. state, state spanning the Mid-Atlantic (United States), Mid-Atlantic, Northeastern United States, Northeastern, Appalachian, and Great Lakes region, Great Lakes regions o ...

. It dates back to the

. It is the lowest member of the Ludlowville Formation and it overlies the Skaneateles Formation. The Peppermill Gulf bed is included within the Centerfield Lime. The unit was named by Smith (1930)

Fossils

This

Limestone Limestone is a type of carbonate rock, carbonate sedimentary rock which is the main source of the material Lime (material), lime. It is composed mostly of the minerals calcite and aragonite, which are different Polymorphism (materials science) ...

unit contains fossils of

crinoids Crinoids are marine invertebrates that make up the class Crinoidea. Crinoids that remain attached to the sea floor by a stalk in their adult form are commonly called sea lilies, while the unstalked forms, called feather stars or comatulids, are ...

rugosa The Rugosa or rugose corals are an extinct Class (biology), class of solitary and Colony (biology), colonial corals that were abundant in Middle Ordovician to Late Permian seas. Solitary rugosans (e.g., ''Caninia (genus), Caninia'', ''Lopho ...

bivalvia Bivalvia () or bivalves, in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class (biology), class of aquatic animal, aquatic molluscs (marine and freshwater) that have laterally compressed soft bodies enclosed b ...

trilobites Trilobites (; meaning "three-lobed entities") are extinct marine arthropods that form the class Trilobita. One of the earliest groups of arthropods to appear in the fossil record, trilobites were among the most successful of all early animals, ...

and brachiopods. This unit also contains several corals including; Eridophyllum and Heliophyllum hali.

References

Devonian geology of New York (state) Devonian Pennsylvania Devonian southern paleotemperate deposits Shale formations of the United States Limestone formations of the United States Claystone formations Mudstone formations of the United States Devonian Ohio Geologic formations of New York (state) Geologic formations of Pennsylvania Geologic formations of Ohio {{NewYork-geologic-formation-stub