Lithofacies of the Wolfcamp and Lower Leonard Intervals, Southern Midland Basin, Texas

Abstract
Basinal mudrocks and associated facies assigned to the Wolfcamp and lower Leonard lithostratigraphic units in the Midland Basin are prolific producers of oil and gas. Four facies are recognized in core on the basis of macroscopic examination, XRD analysis, and ED-XRF elemental chemistry: (1) siliceous mudrock, (2) calcareous mudrock, (3) muddy bioclast–lithoclast floatstone, and (4) skeletal wackestone/packstone. Mudrocks are largely hemipelagic deposits of fine-grained sediment delivered by suspension settling. Floatstones were deposited by debris flows that originated on carbonate shelves around the basin. Wackestones/packstones are finer grained sediment density-flow deposits, probably turbidites, reworked by local bottom currents. These sediments were deposited below storm wave base in a basin having limited connection to the open ocean. During deposition, low-oxygen conditions prevailed in bottom waters and sediments, as shown by the presence of agglutinated foraminifera, rarity of burrows, widespread prevalence of small (
Authors
R. W. Baumgardner, Jr.
H. Scott Hamlin
Harry D. Rowe.
Citation

Baumgardner, R. W., Jr., Hamlin, H. S., and Rowe, H. D., 2016, Lithofacies of the Wolfcamp and Lower Leonard Intervals, Southern Midland Basin, Texas: The University of Texas at Austin, Bureau of Economic Geology, Report of Investigations No. 281, 67 p.

Code
RI281
ISBN
978-1-970007-06-0
ISSN
2475-367X
Number
281
Number of pages
67
Publisher
The University of Texas at Austin, Bureau of Economic Geology
Series
Report of Investigation
Year
2016