THE LAS DELICIAS FM., COAHUILA, MEXICO: PROVENANCE AND TECTONIC SETTING

The present study is the first combined detailed sedimentological, petrological and geochemical analysis of the sedimentary units of the Las Delicias Basin, Coahuila, Mexico. An overall quantity of 89 samples of sedimentary and igneous rocks underwent petrographical and geochemical analysis (major-, trace-, and rare earth elements) were taken from 11 stratigraphic unites: a) Los Remedios Member (Mississippian-Pennsylvanian), b) El Fraile limestone (late Pennsylvanian), c) Los Angelitos/Los Piloncillos limestones (late Pennsylvanian), e) La Venada Member (Cisuralian), f) El Fierro Member (Cisuralian), g) Las Parritas Member (Cisuralian), h) Cañón Rossilo Member (late Cisuralian), i) La Cría Member (Cisuralian-latest Guadalupian), j) Cerro Prieto Member (Guadalupian), and k) San Pedro Member (Guadalupian). The stratigraphic, sedimentological, petrological and geochemical information reveals a new tectonic model of the late Paleozoic. This process marks the last stage of the development of the Ouachita-Marathon orogenic belt.