ABSTRACT

The Sabine Arch is a large (12,000 mi²), low-amplitude anticline centered on the Texas-Louisiana border. A basement-cored feature formed in the Jurassic, the arch has been interpreted as (1) a Jurassic horst that persisted throughout the Cretaceous as a topographic relict of rifting, (2) a dome caused by deep-seated Cretaceous plutonism, and (3) a fold caused by regional tectonism. Using regional maps and cross sections derived from 811 well logs, we tested models of the origin of the Sabine Arch by establishing arch movement history. Our results show that the horst and plutonic dome models do not adequately explain the cause of the Sabine Arch.

Thin salt over the Sabine Arch shows that it was a positive area in the Middle Jurassic, but by the Late Jurassic this positive area had subsided. From the Late Jurassic through the late Early Cretaceous the Sabine Arch had no topographic expression. Mid-Cretaceous movement caused 550 ft (168 m) of uplift on a north-trending, elongated arch. After another period of submergence in the Late Cretaceous and Paleocene, a second episode of arching occurred in the early Eocene.

Cretaceous and Tertiary uplift may have reactivated an earlier positive area, but the cause of reactivation has not been previously specified. The Sabine Arch is interpreted as a fold caused by lateral compression of the Gulf of Mexico basin. Mid-Cretaceous arching is contemporary with thrusting and associated tectonic highlands in the Arizona-Mexico segment of the North American Cordillera, and Eocene arching is coincident with Laramide folding and thrusting. Compressional tectonics in the northern Gulf Basin is consistent with recent geodynamic models that indicate wide zones of foreland and intraplate deformation during orogenesis.