The origin of the Sabine Uplift can be found in the same processes that formed the Gulf of Mexico (GOM) Basin. The Sabine Uplift is supported by a large rhombic basement block that originated as a mid-rift high during the Triassic rifting phase of the opening of the GOM. Although this area is referred to as a basement block, it is in reality an area some 90 miles long by 60 miles wide, across which the depth to magnetic basement is up to 10,000 ft shallower than in the middle of the East Texas Salt Dome Basin. The northeast and southwest boundaries of this basement block are major transform (transfer) fault systems that parallel the opening of the Gulf of Mexico. The northwest boundary is the East Texas Salt Dome rift basin and the southeast side steps down into the South Louisiana Salt Dome Basin. Within this mid-rift high, multiple smaller transform faults and horst and graben structures are evident by mapping the base of the Louann Salt on seismic data. These structures have influenced sedimentation on a local level. Further uplift of this mid-rift high occurred during the Middle to Late Cretaceous and Paleocene-Eocene due to Laramide foreland compression from the southwest.

The mid-rift high was nearly covered by Louann Salt. At the same time, an estimated 5,000 to 7,000 feet of salt was being deposited in the East Texas Salt Dome Basin. Salt isochrons can thus tell us something of both the external and internal shape of the mid-rift high. Two notable salt isochron thins are evident on the structure: the Halbouty Ridge along the Smith-Rusk County line and the San Augustine High, both defined by thin or absent salt.

The shape of the mid-rift high has also influenced younger sedimentary depositional patterns. Southwest of the Trinity River and east of the Louisiana state line, the Haynesville-Bossier- Cotton Valley (HBCV) system is aggradational—major system tracts are stacked vertically. But, the presence of the mid-rift high forced the HBCV system to prograde across a flat marine shelf over the mid-rift high. Thus, over the Sabine Uplift the same system tracts cover an area that is nearly three times as wide as their coverage to the southwest or to the east.

The mid-rift high was a shallow marine shelf during the Cotton Valley sand deposition. The Cotton Valley sands across the mid-rift high are shoreface sands that were laid down along a shoreline that extended from southwest to northeast across the shallow shelf. The sands of Overton (Cotton Valley) Field, as well as the sands at Oak Hill, Willow Springs and Carthage, are all examples of this deposition. Thin widespread limestone beds are present within the Cotton Valley across the Sabine Uplift. These limestones are interpreted as transgressive shell lags and back-bay oyster beds. The position of the active shoreface systems prograded through time, with the oldest system to the northwest and the youngest migrated to the southeast.

Middle to Late Cretaceous Laramide foreland tectonics involved lateral compression from the southwest that formed a foreland fold pair, the Sabine Uplift and the North Louisiana Salt Basin. Estimates of the amount and timing of that uplift are consistent with earlier studies dating back to Granata, in 1953. Younger Paleocene- Eocene compression reactivated the uplift again. Pre-Jurassic transform (transfer) fault lineations along NW–SE lines strongly influenced the shape and style of the resultant uplift. The current outline of the Sabine Uplift as defined by the edge of the Wilcox outcrop is very rectangular along a NW–SE axis.

Any exploration program for the Sabine Uplift area should include a serious consideration of Laramide compressional tectonics, sub-salt structuring, and both gravity and magnetic mapping early in the evaluation.

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