Invertebrate Paleoecology of High Paleo-latitude Carboniferous Strata of the Tepuel-Genoa Basin, Argentina

Abstract

The Late Paleozoic Ice Age (LPIA), which began in the latest Devonian and ended in the Late Permian, was a time of active environmental changes. During this time, glaciers waxed and waned over the ancient continent of Gondwana that was situated over the southern pole. This time of transition from icehouse to greenhouse in the Permian is our closest analogue to our current environmental conditions and increased knowledge of our planetary past will greatly influence our future. Much of the previous research on marine invertebrate paleoecology during the LPIA occurs in far-field or low paleolatitude localities, but less is known about the state of near-field invertebrate faunas of this time. The focus of this study is on the paleoecology of the high paleolatitude communities in the Tepuel-Genoa Basin in western Argentina in which the hypothesis that ice proximal, near-field paleocommunities differed significantly from those in far-field regions during glacial episodes is tested. Sedimentological and paleoecological data were collected and analyzed in two sections of the Pampa de Tepuel Formation (the lower and middle sections) in the Tepuel-Genoa Basin. In the lower Pampa de Tepuel Formation, diversity and fossil abundance was higher than in the middle section. These differences are accredited to changes in environmental factors attributed to the proximity to glacial sediment input at the time of deposition. Similar to low latitude studies, the effects of the LPIA glacial fluctuations differ by location. However, the changes in the high-latitude paleocommunities occur with fluctuations in the environment within the Pampa de Tepuel Formation.