| Finlay Limestone | |
|---|---|
| Stratigraphic range: Albian PreꞒ Ꞓ O S D C P T J K Pg N | |
 Limestone mountains of Finlay Limestone in Aquiles Serdán Municipality near Chihuahua City. | |
| Type | Formation |
| Unit of | Fredericksburg Group |
| Underlies | Del Norte Formation |
| Overlies | Cox Sandstone |
| Thickness | 130–426 feet (40–130 m) |
| Lithology | |
| Primary | Limestone |
| Other | Sandstone |
| Location | |
| Coordinates | 31°22′N 105°36′W / 31.36°N 105.60°W / 31.36; -105.60 |
| Region | New Mexico Texas Chihuahua |
| Country | United States Mexico |
| Type section | |
| Named for | Finlay Mountains |
| Named by | G.B Richardson |
| Year defined | 1904 |
  Finlay Limestone (the United States)Show map of the United States Finlay Limestone (Texas)Show map of Texas | |
The Finlay Limestone is a geologic formation in western Texas, southern New Mexico, and northern Chihuahua. It preserves fossils dating back to the early Cretaceous period.
Description
The formation is composed of massive gray limestone with a few thin beds of brown sandstone, with a total thickness of 130–426 feet (40–130 m). It is exposed in the Finlay Mountains (31°22′N 105°36′W / 31.36°N 105.60°W / 31.36; -105.60), the Sierra de Juarez, and the Cerro de Cristo Rey uplift (31°47′13″N 106°32′46″W / 31.787°N 106.546°W / 31.787; -106.546). The formation overlies the Cox Sandstone and is overlain by the Del Norte Formation.
Fossils
The formation is highly fossiliferous, containing fossils characteristic of early Cretaceous Albian and Comanchean age.
Economic resources
The formation includes carbonate replacement deposits of lead, zinc, and silver in northern Mexico, along the Chihuahua CRD belt.
History of investigation
The formation was first defined by G.B. Richardson in 1904 and assigned to the Fredericksburg Group.
See also
Footnotes
- ^ Richardson 1904
- ^ Lovejoy 1976
- Kottlowski 1973
- Robertson, Ken; Megaw, Peter (June 2009). "Cinco de Mayo: A new silver, lead, and zinc discovery in northern Mexico". The Leading Edge. 28 (6): 730–735. doi:10.1190/1.3148416.
References
- Kottlowski, F.E. (1973). "Pre-Pliocene rocks in La Mesa region, southern Dona Ana County, New Mexico". El Paso Geological Society Field Trip Guidebook. 7: 37–46.
- Lovejoy, E.M.P. (1976). "Geology of Cerro de Cristo Rey uplift, Chihuahua and New Mexico" (PDF). New Mexico Bureau of Mines and Mineral Resources Memoir. 31. Retrieved 3 August 2020.
- Richardson, G.B. (1904). "Report of a reconnaissance in Trans-Pecos Texas north of the Texas and Pacific Railway". University of Texas, Mineral Survey Bulletin. 9.