The Medina Group or Cataract Group is a

geologic group In geology, a group is a lithostratigraphic unit consisting of a series of related formations that have been classified together to form a group. Formations are the fundamental unit of stratigraphy. Groups may sometimes be combined into superg ...

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 * ...

. It dates to the

Silurian The Silurian ( ) is a geologic period and system spanning 23.5 million years from the end of the Ordovician Period, at million years ago ( Mya), to the beginning of the Devonian Period, Mya. The Silurian is the third and shortest period of t ...

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 ...

. The group includes the

Whirlpool Sandstone A whirlpool is a body of rotating water produced by opposing currents or a current running into an obstacle. Small whirlpools form when a bath or a sink is draining. More powerful ones formed in seas or oceans may be called maelstroms ( ). ''Vo ...

Power Glen Shale The Power Glen Shale is a geologic formation in New York. It preserves fossils dating back to the Silurian period. See also * List of fossiliferous stratigraphic units in New York This article contains a list of fossil-bearing stratigraphic u ...

Devils Hole Sandstone A devil is the personification of evil as it is conceived in many and various cultures and religious traditions. Devil or Devils may also refer to: * Satan * Devil in Christianity * Demon * Folk devil Art, entertainment, and media Film and ...

Grimsby Formation The Grimsby Formation is a geologic formation in New York. It preserves fossils dating back to the Silurian period. See also * List of fossiliferous stratigraphic units in New York This article contains a list of fossil-bearing stratigraphic ...

Thorold Sandstone Thorold is a city in Ontario, Canada, located on the Niagara Escarpment. It is also the seat of the Regional Municipality of Niagara. The Welland Canal passes through the city, featuring lock 7 and the Twin Flight Locks. History The first surv ...

Cambria Shale Cambria is a name for Wales, being the Latinised form of the Welsh name for the country, . The term was not in use during the Roman period (when Wales had not come into existence as a distinct entity) or the early medieval period. After the A ...

, Cabot Head Shale and

Kodak Sandstone The Eastman Kodak Company, referred to simply as Kodak (), is an American public company that produces various products related to its historic basis in film photography. The company is headquartered in Rochester, New York, and is incorporated i ...

References

Geologic groups of New York (state) Silurian New York {{NewYork-geologic-formation-stub