Date of Award
1981
Document Type
Thesis
Degree Name
Master of Science (MS)
Department
Geology
First Advisor
A.M. Cvancara
Abstract
The stratigraphy, structure, and depositional environments of the Naborton, Do let Hills, and part of the Cow Bayou Formations (Wilcox Group, Paleocene) at the Oxbow Mine site, Red River, De Soto, and Natchitoches Parishes,. Louisiana, were evaluated from a study of four continuous cores and 466 geophysical logs.
Overlying 40 feet {12 m) of silty Porters Creek shale is the Naborton Formation composed of 130-195 feet (40-59 m) of sand, silt, clay, and lignite. There are three lignites in this formation and their average total thickness is 13.5 feet (4. l m), or about 10% of the formation thickness. The maximum individual lignite thickness is 11 feet (3.4 m}. The lateral extent of each lignite is controlled by recent erosion and by some thick sand units in the Naborton and Dolet Hills Formations. The Dolet Hills Formation is composed of 55-208 feet (17-63 m) of sand with interbedded silt and clay. The Cow Bayou Formation is composed of sand, silt, clay, and lignite. It is generally restricted to the southern and eastern parts of the study area because it has been removed by recent erosion elsewhere. A lignite at the base of this formation has a maximum thickness of 6 feet (1.8 m).
The lowest lignite in the Naborton Formation, with the simplest structure, strikes N. 35° E. with an average dip of 39 feet per mile (7.4 m/km) to the southeast. The overlying lignites are folded and are often structurally higher over thick sand units due to differential ·compaction. Normal faults with throws of up to 50 feet (15.2 m} are present in the northern part of the study area.
The Naborton Fonnation was probably deposited in distributary channel, levee, crevasse splay, overbank, and swamp environments. The depositional setting probably progressed from lower delta plain toward the transition with upper delta plain, and sediment transport was probably from north to south and northwest to southeast through the study area during Naborton deposition. The Dolet Hills Formation was probably deposited in distributary channel, fluvial channel, crevasse splay, and lacustrine environments. The Cow Bayou Formation probably was deposited in crevasse splay, overbank, and swamp environments.
Recommended Citation
Halle, Richard E., "Stratigraphy and depositional environments of the Wilcox Group (Paleocene) at the Oxbow Mine site, northwestern Louisiana" (1981). Theses and Dissertations. 118.
https://commons.und.edu/theses/118