Contributions to the stratigraphic and structural interpretation of the nothwestern portion of the Sierra de Catorce, San Luis Potosí, México

Abstract

The Sierra de Catorce is an uplifted and internally strongly folded prominent structure (tectonic horst) in northern San Luis Potosí State, which exposes in its central parts some of the oldest stratigraphic units recognized in the Mesa Central province. The intense deformation, the absence of fossils in some units and the lack of reliable geochronological data, have generated several controversies among the different authors who interpreted the stratigraphy and structure of this area. The available data, collected from detailed cartography, measurement of stratigraphic profiles and structural, petrographic, geochemical, sedimentological and geochronologic investigations allow to define some details of the geologic evolution of the region. Two phases of compressive deformation are evident through the presence of two cleavage sets in the oldest unit, tentatively located in the Late Triassic, and a single set, corresponding to a similar phase in the Jurassic and Cretaceous strata. Furthermore, the results confirm the presence of volcanic products of the Early Jurassic Cordilleran volcanic arc in this area, which was followed by an extensional phase. The record of the Jurassic marine transgression is present in the region at the upper part of the La Joya Formation (Callovian) and the limestones of the Zuloaga Formation (Oxfordian). A second extensive phase probably occurred after the Laramide Orogeny, in Eocene– Oligocene, being possibly still active in Miocene, leading to the uplifting of the Sierra de Catorce area. The presence of detachment structures might also be related to the Laramide compression, as well as to layer-parallel slide processes as a consequence of the uplift movements. Later, the region is affected by (1) northwest trending strike slip faults, and (2) Miocene–Pliocene andesitic-basaltic magmatism, both seemingly related to the San Tiburcio lineament, a wide transcurrent fault zone that strikes from northwest to southeast in the south-southwest vicinity of the Sierra de Catorce.