Late Paleozoic latitudinal shift of Gondwana : stratigraphic/sedimentologic and biogeographic evidence from Bolivia

• Main Authors: Díaz Martínez, Enrique, Isaacson, Peter E., Sablock, Peter E.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Lyon : Laboratoire de géologie de la Faculté des sciences de Lyon 1993
• Subjects: Gondwana; Late Paleozoic; Bolivia; Paleoclimatology; Paleogeography; Biogeography; Paléozoîque supérieur; Bolivie; Paléoclimatologie; Paléogéographie; Biogéographie; Paleozoico superior; Paleoclimatologia; Paleogeografia; Biogeograffa; geo; envir; The Altiplano; Ice Sheet
• Online Access: https://www.persee.fr/doc/geoly_0750-6635_1993_act_125_1_1553

Late Paleozoic latitudinal shift of Gondwana : stratigraphic/sedimentologic and biogeographic evidence from Bolivia. Detailed stratigraphic, sedimentologic, and biostratigraphic studies of the Late Paleozoic (Devonian through Permian) 5 km-thick sedimentary record in the Altiplano of Bolivia suggest a significant paleolatitudinal shift, from 60° S to at least 25° S during this interval. Devonian cold-water faunal assemblages (Malvinokaffric Realm) occur within the Icla-Belén and lower Sicasica-Huamampampa formations. There are megafaunal immigrants from North Africa during Middle Devonian time. Palynological data from the Colpacucho Fm. (Late Devonian) suggest that there was a strong influx of taxa from North Africa, and there was a taxonomic tie with northeastern USA. Late Devonian (Famennian) glacial marine deposits (Cumaná Formation), include evidence for local development, advance, and retreat of a marine ice sheet. The Lower Carboniferous records the retreat of the glaciers to adjacent highlands, and the continuation of a wave- and storm-dominated clastic shelf, with gradual progradation of braided deltaic plains (Kasa Formation). These deltas appear in discrete progradation, probably as a result of «jökulhlaups», or similar processes frequent in temperate glacial environments. An increase of vegetation is suggested by a change in fluvial depositional style to higher sinuosity and lower clastic load, together with the presence of coal-rich swamps, paleosols, and rhyzoturbated marshes (Siripaca Formation), indicating a gradual shift to warmer climate by the mid-Carboniferous (Serpukhovian). A mid-Carboniferous unconformity of probable tectonic origin is broadly present which correlates with synchronous global events, and is marked by the local erosion of part of or the whole Lower Carboniferous and Upper Devonian sequence. A gradual marine transgression takes place during the Late Carboniferous, coming into the region from the north. The rise in base levels produced a sequence of fluvial, deltaic and coastal ...