Paleoecological and paleoenvironmental implications of a high-density Chondrites association in slope deposits of the Neogene Santo Domingo Formation, Valdivia, south-central Chile

摘要

Neogene marine strata of the Santo Domingo Formation crop out in the vicinity of Valdivia, south-central Chile (40 degrees S, 73 degrees W). The succession is characterized by dark-gray sandy siltstone with abundant Chondrites isp. The occurrence of this ichnotaxon and lower-bathyal benthic foraminifers is consistent with a slope depositional environment. The abundance of Chondrites and the low ichnodiversity reveal poorly oxygenated bottom waters. The Santo Domingo Formation most likely accumulated in fault-controlled, intraslope silled minibasins, which werw formed during a major event of Neogene subsidence of the Chilean margin.