Paleoenvironmental and sequence stratigraphic framework of the Cambrian–Ordovician transition in the Angosto del Moreno area, Northwest Argentina

Abstract

The Cambrian–Ordovician transition has been the focus of a series of biostratigraphic studies in Northwest Argentina (e.g., Benedetto, 1977; Aceñolaza, 1983; Aceñolaza and Aceñolaza, 1992; Rao and Hunicken, 1995; Tortello and Aceñolaza, 1999). However, there is a remarkable absence of detailed stratigraphic sections and only a few studies deal with the associated sedimentary facies and the sequence stratigraphic framework of the Cambrian–Ordovician successions (Moya, 1998; Buatois and Mángano, in press). This has historically precluded a more accurate biostratigraphic zonation and placing of the Cambrian–Ordovician boundary. The aim of this paper is, therefore, to provide a paleoenvironmental and sequence stratigraphic framework for the Cambrian–Tremadocian succession exposed at the Angosto del Moreno area, in the southwest region of the Eastern Cordillera, Jujuy Province. Although this paper is focused on this particular section, information from other areas in Eastern Cordillera has been used for the recognition of allostratigraphic surfaces and stratal stacking patterns. We emphasize that integrated paleontologic (body and trace fossils), sedimentologic and sequence stratigraphic studies are essential in biostratigraphy. Paleontological data and biostratigraphic analysis is presented in Moya et al. (this volume).