Paleotopographic and Structural Controls on Non-Marine Sedimentation of the Lower Cretaceous Antlers Formation and Correlatives, North Texas and Southeastern Oklahoma1
David K. Hobday, C. M. Woodruff, Jr., Mary W. McBride, 1981. "Paleotopographic and Structural Controls on Non-Marine Sedimentation of the Lower Cretaceous Antlers Formation and Correlatives, North Texas and Southeastern Oklahoma", Recent and Ancient Nonmarine Depositional Environments: Models for Exploration, Frank G. Ethridge, Romeo M. Flores
Download citation file:
The Antlers Formation is a Cretaceous fluvial, deltaic, and strandplain unit up to 300 m thick that accumulated basinward of the Wichita-Arbuckle-Ouachita highlands, it extends downdip to an arbitrary, nomenclatural southern limit at the landward pinchout of the Glen Rose Formation, a shallow marine carbonate unit that divides the clastic succession into the Twin Mountains Formation below and the Paluxy Formation above.
Initial Early Cretaceous downwarping marginal to the East Texas Embayment generated a series of small alluvial fans along the highland front. The more extensive chert-rich gravel sheets shed from the Wichita-Arbuckle Mountains terminated distally in gravelly tongues that interfinger with mixed-load alluvial deposits. The sandy component of the mixed-load facies comprises recycled Paleozoic and Triassic sediments of the Wichita Paleoplain that extended across central and west Texas. Rivers depositing the mixed-load facies are thought to have combined the attributes of sinuous, undivided (meandering) channels and low sinuosity, divided (braided) channels; this pattern may have resulted from seasonal variations in discharge in a generally subtropical environment. Subsurface isolith maps show major dip- oriented sand trends representing a concentration of multistoried channel-fill deposits over the inactive Sherman Syncline, Kingston Syncline, and along the flanks of the Muenster Arch. These trends are replaced downdip by strike- parallel sands of deltaic and strandplain origin, which also occupy reentrants between fluvial axes.
Contemporaneous ash-fall layers liberated uranium in updip areas of ground-water recharge. Ground-water flow along dip-oriented sand trends transported uranium in solution, with some precipitation occurring within carbonaceous overbank clays in immediate contact with the channel sands. Most mineralization, however, probably occurs downdip in subsurface channel sands, as favorable hydrologic and geochemical gradients probably existed there shortly after deposition.