Brachiopod faunas from the Permian sequences of northern Chile

CISTERNA, G.A. ; NIEMEYER, H.R.

Melbourne

Congreso; 6th International Brachiopod Congress; 2010

Deakin University

Brachiopod assemblages from the Permian carbonate sequences of northern Chile have been studied in different localities (Cerros de Cuevitas (Salar de Navidad area), Cerro El Árbol and Cerro 1584 (Augusta Victoria area) and Cerro Juan de Morales in the Iquique area). These assemblages can be integrated into a highly diversified fossil fauna composed of bryozoans, crinoids, bivalves and gastropods. A preliminary study suggests that the brachiopod faunal assemblages identified are typically dominated by large shells of two productid genera: Kochiproductus and Waagenoconcha. However, Waagenoconcha appears restricted to the northernmost part of the studied area (Juan de Morales Formation), where it is associated with Artinskian‐Kungurian foraminifera. Kochiproductus, accompanied by a more diversified brachiopod fauna (mainly species of the genera Kozlowskia, Cleiothyridina, Composita, Neospirifer, Hustedia), is the dominant and common element in the rest of the localities studied. The age of these localities, bearing Kochiproductus‐dominated brachiopod fauna, appear to be slightly older than the Juan de Morales Formation. The brachiopod faunas from northern Chile show clear affinities with those from the Copacabana Formation of Perú and its equivalents in Bolivia, as well as sharing some common elements with faunas from the northwestern Argentina (Arizaro Formation). Kochiproductus is also known from Permian clastic sediments in central western Argentina (Río Blanco and Paganzo basins), where it occurs in mixed faunas with boreal and Tethyan elements.