The Tansill Formation is a
geologic formation in southeastern
New Mexico and west
Texas, United States.
[DeFord ''et al.'' 1928] It preserves
fossils
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in ...
dating back to the late
Guadalupian Age
Age or AGE may refer to:
Time and its effects
* Age, the amount of time someone or something has been alive or has existed
** East Asian age reckoning, an Asian system of marking age starting at 1
* Ageing or aging, the process of becoming older ...
of the
Permian period.
[Tait ''et al.'' 1962]
Description
The formation consists of
limestone,
siltstone
Siltstone, also known as aleurolite, is a clastic sedimentary rock that is composed mostly of silt. It is a form of mudrock with a low clay mineral content, which can be distinguished from shale by its lack of fissility.Blatt ''et al.'' 1980, p ...
, and
anhydrite that is extensive in the subsurface in southeastern New Mexico and west Texas. The formation is mostly limestone in the south and west, around the rim of the
Delaware Basin
The Delaware Basin is a geologic depositional and structural basin in West Texas and southern New Mexico, famous for holding large oil fields and for a fossilized reef exposed at the surface. Guadalupe Mountains National Park and Carlsbad Cavern ...
, and grades into anhydrite in the north and east. It forms the top of the Capitan reef but dips steeply into the subsurface.
[DeFord and Riggs 1941] It has a total thickness of .
[Newell ''et al.'' 1953] It overlies the
Yates Formation.
[King 1948] The formation is part of the
Artesia Group, which is interpreted as a shelf rock sequence.
History of investigation
The formation was first named by DeFord ''et al.'' in 1938
and formally defined in 1941 and assigned to the (now abandoned) Whitehorse Group.
Tait ''et al.'' assigned it to the newly defined
Artesia Group in 1962.
See also
*
List of fossiliferous stratigraphic units in New Mexico
*
Paleontology in New Mexico
Paleontology in New Mexico refers to paleontological research occurring within or conducted by people from the U.S. state of New Mexico. The fossil record of New Mexico is exceptionally complete and spans almost the entire stratigraphic column. ...
Footnotes
References
*
*
*
* Newell, N.D., Rigby, J.K., Fischer, A.G., Whiteman, A.J., HIckox, J.E., and Bradley, J.S., 1953, ''The Permian reef complex of the Guadalupe Mountains region, Texas and New Mexico; a study in paleoecology'': San Francisco, W.H. Freeman and Company
* {{cite journal , last1=Tait , first1=D.B. , last2=Ahien , first2=J.L. , last3=Gordon , first3=A. , last4=Scott , first4=G.L. , last5=Motts , first5=W.S. , last6=Spitler , first6=M.E. , title=Artesia Group of New Mexico and West Texas , journal=AAPG Bulletin , date=1962 , volume=46 , issue=4 , pages=504–517 , doi=10.1306/BC74383B-16BE-11D7-8645000102C1865D
Permian formations of New Mexico
Permian formations of Texas