IDEAN   23403
INSTITUTO DE ESTUDIOS ANDINOS "DON PABLO GROEBER"
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Substrate and oxygen conditions and their role in the preservation of the first record of articulated ophiuroids for the Mesozoic of South America: preliminary results
Autor/es:
GIACHETTI, LUCIANA; GUTIÉRREZ, CAROLINA; FERNÁNDEZ, DIANA ELIZABETH; PÉREZ, DAMIÁN E.; COMERIO, MARCOS; PAZOS, PABLO JOSÉ
Lugar:
San Miguel de Tucumán
Reunión:
Congreso; XX Congreso Geológico Argentino; 2017
Institución organizadora:
AGA
Resumen:
Recently,the first articulated ophiuroid remains in the Mesozoic of South America werefound in Neuquén basin. Here, their paleoenvironmental setting is interpretedas a low-energy outer ramp setting below the storm wave base, deposited in aperiod of high carbonate productivity and restricted terrigenous input. Weakstorm-derived bottom flows carried bioclasts from more proximal areas.Extracellular polymeric substances and filament-like microstructures aredocumented. Oxygen-deficient bottom waters and fluctuating oxygen levels at thesediment-water interface are envisaged. The bottom flows might have transportedthe ophiuroids for a relatively short distance from their life habitat. In thenew setting, a drop in the oxygen content might explain their death andpreservation of articulated remains. This together with the lack of high energyprocesses and a cohesive substrate (rich in EPS) could have delayeddisarticulation.