Record of a Pennsylvanian - Cisuralian marine transgression, southern Bolivia: a short-lived event in western Gondwana?

HEIDI ANDERSON; ISAACSON PETER; DI PASQUO, M.

PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2017 vol. 485 p. 30 - 45

0031-0182

2017- di Pasquo, M.M., Isaacson, P., Anderson, H., 2016. Record of a Pennsylvanian - Cisuralian marine transgression, southern Bolivia: a short-lived event in western Gondwana? Submitted to PPP (November 2016) (En corrección para ser aceptado en marzo 2017)AUN NO TENGO EL PDF Largely terrestrial Pennsylvanian strata (Macharetí and Mandiyutí groups) in Bolivia and northern Argentina contain abrief marine incursion. Dominated by glacio-fluvial and glacial diamictites, much of the thick succession is peri-glacialin origin and deposited within a basin with paleohighs. In southernmost Bolivia (Balapuca section), new discoveries ofpoorly preserved orthotetacean brachiopods (Derbyoides sp.) document the marine systems. Without the brachiopod,co-occurrence of numerous in situ gastropods (Mourlonia balapucense), with all ontogenetic growth stages, could notbe confirmed as marine. Palynomorphs corresponding to the TB Zone di Pasquo stratigraphically below the megafossil occurrence place the age of the assemblage in the Kasimovian/Gzhelian Stage. Many units show extensive recyclingof Devonian and Mississippian palynomorphs (Retispora lepidophya, and others) and a brachiopod demonstrate pre-Gzhelian erosion and high energy deposition in diamictites during deposition of the Tarija Formation, and throughmuch of the succession. This brief marine transgression in this basin corresponds to regionally more long-lived marinetransgressions in western Argentina, characterized by the Tivertonia-Streptorhynchus Fauna (Moscovian-Gzhelian)linked with the beginning of a global major sea level rise as an interlude in the Gondwana glaciations. The marinetransgression exceeded isostatic rebound. Further in Bolivia, the transgression from the north produced theCopacabana Formation carbonates. Coeval siliciclastics of the San Telmo Formation in the south show contrasting inlithologic facies and faunal composition as a result of thermal barriers (warm ? cold waters).palynostratigraphy; faunal endemism; deglacial transgression; southernconnection?; San Telmo Formation; Tarija Basin