How was Mancos Shale formed?
Here in the valley, the Mancos Shale is 2,300 feet thick and was formed about 99 to 90 million years ago in a near shore area of a large inland sea. It was deposited as the inland sea retreated. Only a few scattered fossils have been found in this layer. Directly above the Point Lookout is the Menefee Formation.
Where is the Mancos Shale?
The Mancos shale is a Late Cretaceous geologic formation of the Western United States, located in New Mexico and Colorado, dominated by mudrock that accumulated in offshore and marine environments of the Cretaceous Western Interior Seaway.
What type of rock is Mancos Shale?
Mancos shale. Dark-gray or lead-colored shales, nearly always somewhat sandy. Contains thin calcareous layers which in places become almost limestones and are usually rich in fossils. Sand locally increases to form sandstone, but no limestone or sandstone layer is persistent and prominent enough to be traced far.
How was the San Juan Basin formed?
The San Juan Basin formed during the Late Cretaceous-early Tertiary Laramide orogeny as an asymmetric syncline that steepens the northwest limb (Kernodle, 1996). In most areas, the basin is well defined by bounding faults and other structural features (for example, the Defiance and Nutria Monoclines).
What is Mancos Shale made of?
The Mancos Shale in the Piceance Basin of Colorado contains an estimated mean of 66 trillion cubic feet of shale natural gas, 74 million barrels of shale oil and 45 million barrels of natural gas liquids, according to an updated assessment by the U.S. Geological Survey.
What does Mancos Shale look like?
Shale comes in many dull earthy colors, reflecting its muddy heritage, but the Mancos Shale is generally a dark grey to nearly black, thanks to its rich content of organic carbon.
Is Mancos Shale sedimentary?
The mud-dominated Mancos Shale Formation, which is composed of interbedded sand, silt and clay, is of research 1 Page 3 interest because it was deposited in a muddy shelf environment in an epicontinental sea (Li and Schieber, 2018). It preserved various sedimentary structures (ripples, laminations, etc.)
What province can the Permian Basin be found in?
The Permian Basin is a large sedimentary basin in the southwestern part of the United States. The basin contains the Mid-Continent Oil Field province. This sedimentary basin is located in western Texas and southeastern New Mexico.
When did the Paradox Basin form?
The Paradox Basin is an asymmetric foreland basin located mostly in southeast Utah and southwest Colorado, but extending into northeast Arizona and northwest New Mexico. The basin is a large elongate northwest to southeast oriented depression formed during the late Paleozoic Era.
What additional information is provided by the types of fossils found in the Mancos Shale?
What additional information is provided by the types of fossils in the Mancos Shale (figure 4.10)? The fossils indicate that the Mancos was deposited in a marine environment. Some fossils are marine and others are from the land, indicating that the Mancos was deposited along a shoreline or in shallow water.
What is the depositional environment of Mancos Shale?
Geology. The unit is dominated by mudrock that accumulated in offshore and marine environments of the Cretaceous North American Inland Sea. The Mancos was deposited during the Cenomanian (locally Albian) through Campanian ages, approximately from 95 million years ago (Ma) to 80 Ma.