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Bibliographic Details
Main Author: David A. Eberth
Format: Artículo científico
Language:en
Published: Universidad Nacional Autónoma de México 2004
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Online Access:https://www.redalyc.org/articulo.oa?id=57221303
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  • Cerro del Pueblo Fm (Difunta Group, Upper Cretaceous), Parras Basin, southern Coahuila, Mexico: reference sections, age, and correlation David A. Eberth Carlos R. Delgado John F. Lerbekmo Donald B. Brinkman Rubén A. Rodríguez Scott D. Sampson Ciencias de la Tierra México Mesozoic Coahuila dinosaurs Cretaceous Principal and supplementary reference sections provide data that clarify the stratigraphicrelationships and depositional history of the Cerro del Pueblo Formation (CdP) – an important unit inLate Cretaceous paleobiogeographic studies in northeastern Mexico and the Western Interior of NorthAmerica. At Saltillo, the CdP is 162 m thick, much thinner than previously reported. To the west, however,the CdP thickens to 449 m at Rincón Colorado (35 km west of Saltillo) and 540 m at Porvenir de Jalpa(70 km west of Saltillo). A substantial stratigraphic interval of interbedded grey-green and red beds ispresent above the CdP throughout the field area; for consistency, it is assigned to the overlying CerroHuerta Formation (CH).Westward-thickening of the CdP indicates an increased rate of subsidence and accommodation inthat direction, and further suggests that sediment was supplied from the west along a narrow, east–westoriented trough that paralleled the modern Sierra Madre Oriental south of the field area. This troughwas likely the location of an embayment in which CdP sediments first aggraded and then slowly progradedto the east and northeast. Overall, the CdP records deposition in very low gradient lower coastal plainand shallow marine (ramp) settings that were influenced by high-frequency changes in relative sea-leveland coastal storm events.Magnetostratigraphic data from 66 samples collected in the Saltillo area indicate that the CdPwas deposited in magnetochronozones 32n.3r–32n.2n. This magnetostratigraphic interval falls withinthe combined Western Interior ammonite biozones of B. reesidei and B. jenseni, and suggests a maximumabsolute age of 72.5 Ma for the CdP in the Saltillo area. The Campanian–Maastrichtian boundary (hereaccepted as 32n–31r) lies 90 m below the top of the overlying CH. A minimum sediment accumulationrate of 55 cm/1,000 yrs is proposed for the CdP. 2004 artículo científico 1026-8774 https://www.redalyc.org/articulo.oa?id=57221303 en http://www.redalyc.org/revista.oa?id=572 Revista Mexicana de Ciencias Geológicas application/pdf Universidad Nacional Autónoma de México Revista Mexicana de Ciencias Geológicas (México) Num.3 Vol.21