The Middlesex Formation is a carbon rich black shale

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 ...

found in the

Appalachian Basin The geology of the Appalachians dates back to more than 480 million years ago. A look at rocks exposed in today's Appalachian Mountains reveals elongate belts of folded and thrust faulted marine sedimentary rocks, volcanic rocks and slivers of ...

. It represents one of several transgressive events (rising sea levels) during the Late Devonian.

Description

The Middlesex is a laminated dark grey to black mudstones and siltstone. It developed in an

Anoxic The term anoxia means a total depletion in the level of oxygen, an extreme form of hypoxia or "low oxygen". The terms anoxia and hypoxia are used in various contexts: * Anoxic waters, sea water, fresh water or groundwater that are depleted of diss ...

environment. Further evidence of this is the lack of

bioturbation Bioturbation is defined as the reworking of soils and sediments by animals or plants. It includes burrowing, ingestion, and defecation of sediment grains. Bioturbating activities have a profound effect on the environment and are thought to be a pr ...

. There are also sparse sand and silt layers suggesting that they were single event deposits.

References

* * * * Devonian geology of New York (state) Devonian Pennsylvania {{NewYork-geologic-formation-stub