Carlile Shale facts for kids

Quick facts for kids Carlile Shale Stratigraphic range: Turonian ~93.9–89.8Ma PreЄ Є O S D C P T J K Pg N ↓
Rare exposure of the Fairport Chalk member of the Carlile Shale in southern Ellis County, Kansas
Type	Geological formation
Unit of	Colorado Group (lower); or Benton Formation
Sub-units	Juana Lopez (CO, NM) Codell Sandstone Blue Hill Shale Fairport Chalk
Underlies	Niobrara Formation
Overlies	Greenhorn Limestone
Thickness	170–230 feet (52–70 m)
Lithology
Primary	Shale, chalky to carbonaceous
Other	Limestone Sandstone Siltstone Septarians Bentonite
Location
Coordinates	38°22′34″N 104°58′44″W / 38.376°N 104.979°W / 38.376; -104.979
Region	Mid-continental
Country	United States
Type section
Named for	Carlile Spring and Carlile Station, 21 mi west of Pueblo, Colorado
Named by	Gilbert
Year defined	1896

The Carlile Shale is a special type of rock layer found in the central-western United States. It formed during the Cretaceous Period, about 93.9 to 89.8 million years ago. This rock layer is mostly made of shale, which is a type of rock formed from mud.

You can find the Carlile Shale in many states. These include Colorado, Kansas, Nebraska, New Mexico, North Dakota, South Dakota, and Wyoming. It was created from ancient ocean deposits. These deposits formed as a huge inland sea, called the Western Interior Seaway, slowly started to get smaller.

Exploring the Carlile Shale

The Carlile Shale can be seen in different places. For example, along Interstate 70 in Kansas, you can spot low hills made of this rock. These hills are mostly from the Fairport Chalk member, which is a part of the Carlile Shale. Its thin limestone layers make it tougher than other parts.

Near Yocemento, Kansas, you can see slopes of the Blue Hill Shale member. This part of the Carlile Shale is often blue-gray. In some areas, you might even find large, orange-tinted septarian boulders. These are round rocks with cracks inside.

Discovering Ancient Life: Carlile Shale Fossils

The Carlile Shale is a great place to find fossils! Scientists have discovered amazing remains of ancient creatures here.

What Fossils Are Found?

One exciting find in the Blue Hill Shale Member in Kansas is Plesiosaur remains. Plesiosaurs were large, marine reptiles with long necks. They swam in the ancient seas millions of years ago.

In eastern South Dakota, the Carlile Shale also holds other treasures. You can find shark teeth from ancient sharks. There are also fossils of wood and leaves, showing what plants were like back then. Ammonites, which were shelled creatures similar to modern-day Nautilus, are also common finds.

How Scientists Studied the Carlile Shale

Scientists have been studying the Carlile Shale for a long time. They wanted to understand how it formed and what it tells us about Earth's past.

Naming the Carlile Shale

The Carlile Shale was first named by a geologist named Grove Karl Gilbert. He named it in 1896 after Carlile Spring. This spring is located about 21 miles (34 km) west of Pueblo, Colorado. Gilbert described it as a gray shale with limestone or sandstone on top.

Later, in 1931, other geologists like William Walden Rubey mapped the Carlile Shale. They found it stretched into Kansas and the Black Hills. Rubey also linked it to a larger group of rocks called the Colorado Group. In 1948, C.H. Dane connected it to the Mancos Shale in New Mexico.

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