Triassic age of the continental Pular Formation, Sierra de Almeida, Antofagasta, northern Chile

Abstract

In this contribution, we present a reassessment of the Pular Formation age (Sierra de Almeida, Antofagasta) that in previous papers was attributed to either the Late Paleozoic or Triassic. At Quebrada del Medio, the Pular Formation includes a 379-meter-thick stratigraphic section formed from base to top by conglomerates, sandstones, black bituminous shales and limestones, tuffaceous sandstones and a poorly welded ignimbrite that accumulated in fluvial and lacustrine environments. A multidisciplinary study of the flora and fauna was undertaken. The existence of diagnostic Gondwana microflora and macroflora allows attributing a Middle Triassic to early Late Triassic age to the Pular Formation.