The Akron Formation is a geologic formation in New York. It preserves fossils dating back to the Silurian period. The Akron Formation is primarily a mottled...

The Marcellus Formation or the Marcellus Shale is a Middle Devonian age unit of sedimentary rock found in eastern North America. Named for a distinctive...

The Knox Supergroup, also known as the Knox Group and the Knox Formation, is a widespread geologic group in the Southeastern United States. The age is...

it outcrops; in others, especially its Southern Ontario portion, the formation can be less prominent as a local surface feature.[citation needed] In...

The Tully Formation is a geologic unit in the Appalachian Basin. The Tully was deposited as a carbonate rich mud, in a shallow sea at the end of the Middle...

The Devonian Catskill Formation or the Catskill Clastic Wedge is a unit of mostly terrestrial sedimentary rock found in Pennsylvania and New York. Minor...

The Genesee Formation (Group) is a geologic formation in New York. It is equivalent the Harrell Shale in Pennsylvania. It dates back to the Upper Devonian...

The Salina Group or Salina Formation is a Late Silurian-age, stratigraphic unit of sedimentary rock that is found in Northeastern and Midwestern North...

The Monongahela Formation is a geologic formation in West Virginia, Pennsylvania, Ohio, and Maryland. It is dated to the Carboniferous period. The top...

The Rhinestreet Shale is a geologic formation in the Appalachian Basin. It dates back to the Devonian period. The Rhinestreet is an organic or Black Shale...

the Portage Group. The West Falls formation is bounded above by the Java Formation and below by the Sonyea Formation. It comprises the Angola Shale and...

and seeps. After it does, and turns to the east, it flows over the Akron Formation, Bertie Group of dolomitic shales, and the Salina Group. The latter...

Canadian football, a single-wing formation was a precursor to the modern shotgun formation. The term usually connotes formations in which the snap is tossed...

The Ludlowville Formation is a geologic formation in New York, Ohio and Pennsylvania. It dates to the Devonian period. The Owasco is a thin distinct silty...

The Kinzers Formation is a geologic formation in Pennsylvania. It preserves fossils dating back to the fourth stage of the Cambrian Period. The base of...

The Akron, OH Metropolitan Statistical Area, sometimes referred to as Greater Akron, is defined by the United States Office of Management and Budget as...

areas where this Geologic Unit thins it is also called the Black River Formation (undifferentiated). One example of this is over the Cincinnati Arch and...

The Cussewago Formation is a geologic formation in Pennsylvania. It preserves fossils dating back to the Devonian period. Earth sciences portal Pennsylvania...

Helderberg Mountains. The upper portion of the Helderberg, or the Kalkberg Formation is host to the Bald Hill ash bed, dated to 417.6 million years ago. The...

Bertie Limestone, also referred to as the Bertie Dolomite and the Bertie Formation, is an upper Silurian (Pridoli, or Cayugan) geologic group and Lagerstätte...

The Lock Haven Formation is a Devonian mapped bedrock unit in Pennsylvania, in the Appalachian Mountains of the United States. The Lock Haven is gray...

The Washington Formation is a coal, sandstone, and limestone geologic formation located in Ohio, Pennsylvania and West Virginia. It dates back to the Lower...

The Hampshire Formation is a geologic formation in West Virginia, USA. It preserves fossils dating back to the Devonian period. Earth sciences portal...

The Devonian Mahantango Formation is a mapped bedrock unit in Pennsylvania, West Virginia, and Maryland. It is named for the North branch of the Mahantango...

The Bois Blanc Formation is a geologic formation in Michigan. It preserves fossils dating back to the Devonian period. Earth sciences portal Michigan...

The Chagrin Shale is a shale geologic formation in the eastern United States that is approximately 365 million years old. The Chagrin Shale is a gray...

The Bass Islands Formation is a geologic formation in Michigan. It preserves fossils dating back to the Silurian period. Michigan portal Paleontology...

Berea Sandstone, also known as Berea Grit, is a sandstone formation in the U.S. states of Michigan, Ohio, Pennsylvania, West Virginia, and Kentucky. It...

shale with some sandstone. There are two main formations encompassed by the group: the Mahantango Formation and the Marcellus Shale. In southwestern Virginia...

The Allegheny Group, often termed the Allegheny Formation, is a Pennsylvanian-age geological unit in the Appalachian Plateau. It is a major coal-bearing...