Bisbee Basin and Its Bearing on Late Mesozoic Paleogeographic and Paleotectonic Relations Between Cordilleran and Caribbean Regions: ABSTRACT

Abstract

The Bisbee Group and its correlatives in southern Arizona, the New Mexico panhandle, and adjacent parts of Mexico are composed dominantly of Lower Cretaceous nonmarine, marginal marine, and shallow marine deposits, but apparently also include upper Upper Jurassic and lower Upper Cretaceous strata. Farther west, in southwestern Arizona and southeastern California, lithologically similar nonmarine strata of the McCoy Mountains Formation and its correlatives occupy the same general stratigraphic position as the Bisbee Group, but are poorly dated and may be older. The rifted Bisbee basin was a northwestern extension of the Chihuahua Trough, a late Mesozoic arm of the Gulf of Mexico depression. Basal zones of the Bisbee Group were deposited as alluvial fans marginal to active fault blocks during the rift phase of basin development, and are intercalated locally with lavas and ignimbrites. Subsequent thermotectonic subsidence of thinned crust beneath the Bisbee basin allowed intertonguing fluvial, lacustrine, deltaic, strandline, and marine shelf facies to invade the basin and bury the foundered fault-block topography. The upper Lower Cretaceous (Aptian-Albian) Mural Limestone was deposited during the phase of maximum transgression. Differing sandstone petrofacies of quartzose, arkosic, and volcaniclastic character reflect derivation of clastic detritus from varied sources bordering the Bisbee basin.more » The Bisbee basin and Chihuahua Trough developed in relation to Jurassic opening of the Gulf of Mexico, and were associated with changing plate configurations and motions throughout the Mesoamerican region.« less