- Usage in publication:
-
- Lena member
- Modifications:
-
- Original reference
- Dominant lithology:
-
- Clay
- Silt
- AAPG geologic province:
-
- Gulf Coast basin
- Arkla basin
Summary:
Pg. 118 (fig. 26), 151-154, geol. map. Lena member of Fleming formation. Brackish-water calcareous clays with siliceous silts and local pyroclastic lentils. Dominant lithologic unit is the gray silty clay that occurs near base of typical section; this unit incorporates varying thicknesses of more calcareous clays which in places make up almost all of the section; calcareous beds contain foraminifera, whereas the gray silty clays contain carbonaceous particles and grass. Thickness 75 to 125 feet. Underlies Carnahan Bayou member (new); overlies Catahoula formation. [Age is Miocene.]
Typically exposed for 2.5 mi north along Highway 71W from near Lena, Rapides Parish, in sec. 34, T. 6 N., R. 4 W., to a point in Natchitoches Parish, central LA.
Source: US geologic names lexicon (USGS Bull. 1200, p. 2147).
For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.
Asterisk (*) indicates published by U.S. Geological Survey authors.
"No current usage" (†) implies that a name has been abandoned or has fallen into disuse. Former usage and, if known, replacement name given in parentheses ( ).
Slash (/) indicates name conflicts with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005, 2021). May be explained within brackets ([ ]).