What age is the Niobrara Formation?

between 87 and 82 million years ago
The Niobrara Formation, also called Niobrara Chalk, is a geologic formation in North America that was laid down between 87 and 82 million years ago during the late Cretaceous period.

What is the Kansas chalk?

The western Kansas chalk beds became famous in the 19th century for largely complete fossils of giant swimming and flying reptiles known as mosasaurs, plesiosaurs, and pterosaurs as well as fossils of aquatic birds with teeth, 20-foot-long fish, and clams up to six feet in diameter. Resources.

When was the Pierre Shale unit deposited?

70-80 million years ago
Pierre Shale It was deposited during the Campanian and Maastrichtian (~70-80 million years ago). This unit consists of dark gray/black shales that were deposited in deep marine waters. Within the shale unit are several distinct ash layers (bentonites), which have been used to help date the formation.

How is the sedimentary rock chalk formed?

Chalk forms from a fine-grained marine sediment known as ooze. When foraminifera, marine algae, or other organisms living on the bottom or in the waters above die, their remains sink to the bottom and accumulate as ooze.

How did the Niobrara Chalk formation form?

The chalk formed from the accumulation of coccoliths from microorganisms living in what was once the Western Interior Seaway, an inland sea that divided the continent of North America during much of the Cretaceous. It underlies much of the Great Plains of the US and Canada.

Where is the Niobrara basin?

The Niobrara-DJ Basin is a crude oil and liquids rich gas play that is located in Northeast Colorado and Southeast Wyoming. The Niobrara is located in several areas of the Rocky Mountains, including the Powder River in Wyoming and in parts of Northwest Colorado.

How old is fossiliferous limestone?

Limestone. Fossiliferous limestone is representative of the local limestone bedrock. This particular bedrock contains numerous brachiopod fossils. Southwestern Ohio’s limestone (a sedimentary rock) is saturated with life — life from about 450 million years ago, that is.

What mineral is chalk?

mineral calcite
Chalk is a soft, white, porous, sedimentary carbonate rock, a form of limestone composed of the mineral calcite. Calcite is an ionic salt called calcium carbonate or CaCO3. It forms under reasonably deep marine conditions from the gradual accumulation of minute calcite shells (coccoliths).

How old is the Pierre Shale?

Pierre Shale, division of Upper Cretaceous rocks in the United States (the Cretaceous Period lasted from about 146 million to 65.5 million years ago). Named for exposures studied near old Fort Pierre, S.D., the Pierre Shale occurs in South Dakota, Montana, Colorado, Minnesota, New Mexico, Wyoming, and Nebraska.

How old are the Badlands?

500,000 years ago
The rocks of Badlands National Park were deposited as early as 75 million years ago and began eroding just 500,000 years ago. As erosion continues today, fossils buried in the rock slowly reveal themselves and park paleontologists study them to learn about ancient life in the area.

When was chalk formed?

between 100 and 60 million years ago
Most chalks formed during the Cretaceous period, between 100 and 60 million years ago, and chalks of this age can be found around the world. The Cretaceous chalks record a period when global temperatures and sea levels were exceptionally high.

When was chalk invented?

Chalk was formed in the Cretaceous, between 99 and 65 million years ago.