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 City, the most populous city in the United States, located in the state of New York * New York (state), a state in the northeastern United States New York may also refer to: Film and television * '' ...

, Ohio and Pennsylvania. It dates to the

Devonian The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, whe ...

period Period may refer to: Common uses * Era, a length or span of time * Full stop (or period), a punctuation mark Arts, entertainment, and media * Period (music), a concept in musical composition * Periodic sentence (or rhetorical period), a concept ...

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 (plural: diastems) 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 barrel of USA estima ...

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

Fossils

The

brachiopod Brachiopods (), phylum Brachiopoda, are a phylum of trochozoan 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 end, w ...

''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 (; ( Pennsylvania Dutch: )), officially the Commonwealth of Pennsylvania, is a state spanning the Mid-Atlantic, Northeastern, Appalachian, and Great Lakes regions of the United States. It borders Delaware to its southeast, ...

. It dates back to the

. It is the lowest member of the Ludlowville Formation and it overlies the

Skaneateles Formation Skaneateles may refer to, in the United States: * Skaneateles (village), New York, in Onondaga County * Skaneateles (town), New York, in Onondaga County * Skaneateles Lake, one of the Finger Lakes in New York State ** Skaneateles Creek, the creek t ...

. The Peppermill Gulf bed is included within the Centerfield Lime. The unit was named by Smith (1930)

Fossils

This

Limestone Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms whe ...

unit contains fossils of

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

rugosa The rugosa, also called the tetracorallia or horn coral, are an extinct order of solitary and colonial corals that were abundant in Middle Ordovician to Late Permian seas. Solitary rugosans (e.g., '' Caninia'', '' Lophophyllidium'', '' Neoza ...

bivalvia Bivalvia (), in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of marine and freshwater molluscs Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of w ...

trilobites Trilobites (; meaning "three lobes") are extinct marine arthropods that form the class Trilobita. Trilobites form one of the earliest-known groups of arthropods. The first appearance of trilobites in the fossil record defines the base of the At ...

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 {{NewYork-geologic-formation-stub