Title: Micropaleontology and paleogeography of the Upper Mural Limestone of southeastern Arizona and northern Sonora
Abstract: The upper Mural Limestone is a carbonate rock sequence of early and mid-Cretaceous age that crops out in southeastern Arizona and northern Sonora. It was deposited at the northern margin of the Chihuahua Trough during the peak of a major marine transgression, followed by a regression and a less extensive second transgression. Four stratigraphic sections were studied. They form a NW-SE transect that runs along the axis of the Bisbee Basin. Six different facies were recognized based on micropaleontologic studies: 1) biomicrite with Orbitolina; 2) biomicrite with Colomiella; 3) quartz sandstone; 4) oomicrite with biogenic fragments; 5) biomicrite with Dictyoconus, and 6) biomicrite with Nummoloculina. The facies represent a mosaic of environments that range from inner carbonate shelf to shelf basin deposits. The age of the upper Mural Limestone is tentatively considered as Albian-Lower Cenomanian, based on the presence of tintinnids and foraminiferal index fossils. Paleogeographic maps for the Lower, Middle, and Upper Albian based on correlation with adjacent areas are included
Publication Year: 1989
Publication Date: 1989-01-01
Language: en
Type: article
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