The visual analysis of the SIR-A images (Shuttle Imaging Radar) of the folded belt located between Saltillo, Coahuila, and Galeana, in northeastern Mexico, revealed the existence of several geologic features including: (1) a well-developed pattern of en echelon folds, (2) juxtaposition of tectono-stratigraphic domains, (3) fold structures ranging from fan-shaped asymmetric to recumbent doubly plunging anticlines, and (4) anticlinal-synclinal trends displaying marked morphologic variations, associated to regional plunging, twisting, and tilting of the structures. These structures are interpreted as the result of transpressive forces related to a complex, anastomosed wrench-faulting system in the basement, reactivated in the Late Jurassic during active sea-floor spreading i the Gulf of Mexico.

The Saltillo-Galeana orogenic belt is interpreted as the early Tertiary culmination of an ancient Mesozoic (Jurassic and Cretaceous) transpressive deformation generated from an oblique-slip mobile zone in the Gulf of Mexico. This transpressive tectonic model gives the adequate paleogeographic scenario to integrate all previously postulated, apparently incompatible, deformational models for northeastern Mexico, and conciliates the differences in fold vergences observed in the region.

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