The Romeroville Sandstone is a geologic formation in northeastern New Mexico. It likely was deposited in the

Cenomanian The Cenomanian is, in the ICS' geological timescale, the oldest or earliest age of the Late Cretaceous Epoch or the lowest stage of the Upper Cretaceous Series. An age is a unit of geochronology; it is a unit of time; the stage is a unit in the s ...

Age of the Cretaceous Period.

Description

The formation consists of yellow-gray quartz sandstone with minor

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 ...

. The sandstone is planar

crossbedded In geology, cross-bedding, also known as cross-stratification, is layering within a stratum and at an angle to the main bedding plane. The sedimentary structures which result are roughly horizontal units composed of inclined layers. The original ...

and bioturbated and locally pebbly. It overlies the

Pajarito Formation The Pajarito Formation is a geologic formation in eastern New Mexico and west Texas. It preserves fossils dating back to the Albian Age of the Cretaceous Period. Description In Quay County, New Mexico, where the unit was first described, it co ...

and is in turn overlain by the Graneros Shale. Maximum thickness is . The formation is interpreted as the onset of a marine transgression of the

Greenhorn cycle The Greenhorn Limestone or Greenhorn Formation is a geologic formation in the Great Plains Region of the United States, dating to the Cenomanian and Turonian ages of the Late Cretaceous period. The formation gives its name to the Greenhorn cycle ...

History of investigation

The formation was first named by Kues and Lucas in 1987 for previously undivided Dakota Group beds at the Romeroville Gap. Kues and Lucas also identified it at Clayton Lake and in the valley of the Dry Cimarron.

References

Bibliography

* * * {{cite journal , last1=Ziegler , first1=Kate E. , last2=Ramos , first2=Frank C. , last3=Zimmerer , first3=Matthew J. , title=Geology of Northeastern New Mexico, union and Colfax Counties, New Mexico: A Geologic Summary , journal=New Mexico Geological Society Field Conference Series , date=2019 , volume=70 , issue=4 , pages=47–54 , url=https://nmgs.nmt.edu/publications/guidebooks/downloads/70/70_p0047_p0054.pdf , accessdate=1 September 2020 Cretaceous formations of New Mexico Upper Cretaceous Series of North America Cenomanian Stage Sandstone formations of the United States