Producción CyT
Congreso
Autoría
di Pasquo, Mercedes
;
Cisterna, Gabriela
;
Calle Salcedo, Abner
;
López, Shirley
;
Grader,George
;
DI NARDO, JUAN EMILIO
;
Kavali,Pauline
;
Ianuzzi, Roberto
;
Sterren, Andrea
;
Gómez, Jessica
;
Ticona, Yulisa
Fecha
2024
Editorial y Lugar de Edición
CZECH-IN s. r. o.
ISSN
978-80-908364-6-4
Resumen
Información suministrada por el agente en
SIGEVA
The Copacabana Formation crops out in sharp stream bends along strike and waterfalls at Chullpanimayu Creek (c. 3043 m elevation, 17.86669°S, 066.24495°W) close to Apillapampa town in west-central Bolivia. This well-exposed section, 310 m thick, overlies Silurian-Devonian rocks. Paleontologic and radiometric data obtained from field trips in 2007 allowed the reassignment of the section between c. 40 m and 242 m to the Sakmarian, previously dated as Artinskian (Leonardian) based on Eopar...
The Copacabana Formation crops out in sharp stream bends along strike and waterfalls at Chullpanimayu Creek (c. 3043 m elevation, 17.86669°S, 066.24495°W) close to Apillapampa town in west-central Bolivia. This well-exposed section, 310 m thick, overlies Silurian-Devonian rocks. Paleontologic and radiometric data obtained from field trips in 2007 allowed the reassignment of the section between c. 40 m and 242 m to the Sakmarian, previously dated as Artinskian (Leonardian) based on Eoparafusulina and palynology. The U-Pb zircon data from volcanic tuffs in the lower interval of the Copacabana Formation at 120 m (295.2 Ma) and 154 m (293.3 Ma) also constrained the conodont Sweetognathus cf. obliquidentatus (132 m) to the Sakmarian. The first appearance (FAD) of Lueckisporites virkkiae at 69 m, dated as Late Asselian, disagrees with those FADs in the early Sakmarian or mid-Artinskian documented in Brazil, Uruguay, Argentina, Africa, Australia, Oman, and Saudi Arabia, also radiometrically constrained. If U-Pb and conodont ages are correct at Apillapampa, Bolivia may have been an older center of dispersion for some striate and taeniate pollen grains and monolete spores, including Lueckisporites virkkiae. To further test and develop these data, in July 2023 we collected more than fifty samples from the marine to transitional deposits of the Copacabana Formation at Apillapampa for a detailed taxonomic revision and regional stratigraphic distribution of microfossils (conodonts, fusulinids, palynomorphs), brachiopods, other invertebrates, ichnofossils, and plants. The recognition of ‘bridge taxa’ in Gondwana is the main purpose of the Permian Stratigraphy Working Group “Cisuralian Gondwana to Euramerica Correlations,” which started in 2022. This fossil-rich Copacabana Formation will enable us to make more accurate correlations between Gondwanan successions bearing radiometric data as well as ‘standard sections’ (including GSSPs) in Russia, the USA, and China. Therefore, this section can be proposed as a standard for Gondwana.
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Palabras Clave
BOLIVIACOPACABANA FORMATIONGONDWNANA EURAMERICA CORRELATIONSLATE PALEOZOIC