Annona Chalk
The Annona Chalk is a geologic formation in Arkansas, Texas, Louisiana, and Oklahoma.[2] It preserves fossils dating back to the Cretaceous period. The formation is a hard, thick-bedded to massive, slightly fossiliferous chalk. It weathers white, but is blue-gray when freshly exposed. The unit is commercially mined for cement. Fossils in the Annona Chalk include coelenterates, echinoderms, annelids, bivalves, gastropods, cephalopods, and some vertebrate traces.[3] The beds range in thickness, up to over 100 feet in depth in some areas (such as the White Cliffs).[4] There is a gradual transition between the Annona chalk and the underlying Brownstown formation, where chalk and marl are interbedded.[5]
Annona Chalk Stratigraphic range: Cretaceous | |
---|---|
![]() Outcrop east of Clarksville, TX (c. 1910) | |
Type | Sedimentary |
Sub-units | Austin Group |
Underlies | Ozan Formation, Marlbrook Marl |
Overlies | Brownstown Marl, Ozan Formation |
Thickness | 30 Meters |
Lithology | |
Primary | Chalk |
Location | |
Region | Arkansas |
Country | United States |
Type section | |
Named for | Annona, Red River County, Texas[1] |
Named by | Robert Thomas Hill |
Exposures
- Annona Chalk overlying Brownstown Marl at what is now called White Cliffs Natural Area, with the Little River in the foreground, Howard County, AR (c. 1910)
- Another view of the same location (c. 1902)
- Quarry at Whitecliffs Landing (c. 1902)
Paleofauna
Ammonites
- N. (Nostoceras) danei[6]
- N. (Nostoceras) monotuberculatum[6]
- N. (Nostoceras) plerucostatum[6]
- N. (Nostoceras) pulcher[6]
- Oxybeloceras
- O. crassum[6]
Ostracods
|
|
References
- Hill, R.T. (1894). "Geology of parts of Texas, Indian Territory and Arkansas adjacent to Red River". Bulletin of the Geological Society of America. 5: 308.
- USGS Geolex, Annona Chalk/Formation
- R. T. Hill. "ANNONA CHALK/FORMATION". Arkansas Geological Survey. v. 5: Arkansas Geological Survey. p. 308. Archived from the original on 1894. Retrieved 25 May 2015.CS1 maint: location (link)
- Veatch, Arthur Clifford (1906). Geology and Underground Water Resources of Northern Louisiana and Southern Arkansas. U.S. Government Printing Office.
- Matson, G. C., 1916, The Caddo Oil and Gas Field, Louisiana and Texas, USGS Bulletin 619
- Kennedy, W. J.; Cobban, W. A. (1993). "Campanian ammonites from the Annona Chalk near Yancy, Arkansas". Journal of Paleontology. 67 (1): 83–97.
- Collins, Jr., Robert J. (June 1960). Stratigraphy and Ostracoda of the Ozan, Annona, and Marlbrook Formations of southwestern Arkansas (PhD). Louisiana State University and Agricultural and Mechanical College.
- Various Contributors to the Paleobiology Database. "Fossilworks: Gateway to the Paleobiology Database". Archived from the original on 31 July 2014. Retrieved 8 July 2014.
- Notes on the Annona Chalk, Norman L. Thomas and Elmer M. Rice, Journal of Paleontology, Vol. 6, No. 4 (Dec., 1932), pp. 319–329
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.