INSTITUTO SUPERIOR DE CORRELACION GEOLOGICA
Unidad Ejecutora - UE
Integrated study of fauna and microflora from the Early Devonian (Pragian?Emsian) of northwestern Argentina.
NOETINGER, S.; DI PASQUO, M. ; ISAACSON, P.; ACEÑOLAZA, G.F.
Taylor & Francis
Lugar: London; Año: 2015 vol. 9 p. 1 - 1
The Devonian System in northern Argentina has been broadly analysed, but details of its lithologies, biostratigraphy andfossil content have not been presented in a comprehensive study. We performed the first integrative analysis of thepalynological and macrofossil content from the Pescado Formation at the Zenta Range, Argentina. We define a newspecies of cryptospore and extend the stratigraphic record of the ichnogenus Psammichnites isp. for South America. Thestratigraphic ranges of the palynomorphs suggest a time span from the ?late Lochkovian to Pragian?earliest Emsian, butthe co-occurrences of key invertebrates narrow the age of the beds to the late Pragian and early Emsian. Moreover,sedimentary analysis indicates a proximal shoreface?foreshore depocenter during this time range for the Zenta region.The contraction phase of the basin during the middle Pragian and Emsian is evidenced by the presence of sand bodies atthe top of the column and the higher supply of terrigenous components. During this regression event, a low diversityMalvinokaffric Realm brachiopod assemblage occurs, with dominance of Australospirifer hawkinsi. The predominanceof the latter species during this event is coeval with the first decline of the Malvinokaffric Realm in the neighbouringParana´ basin.