Facies de patch reefs en la Formación Picún Leufú (límite Jurásico/Cretácico) en la región de Zapala, Cuenca Neuquina

Resumen

Patch reefs facies in the Picún Leufú Formation (Jurassic/Cretaceous boundary) in the
Zapala region, Neuquén Basin, Argentina. In the locality of Cerrito Caracoles, situated in the nearby of
Zapala city, in the western central region of the Neuquén province, Argentina, the basal part of the Picún Leufú
Formation (Jurassic/Cretaceous boundary) crops out. The facies and microfacies association analysis points out to
an inner shelf margin environment, with development of well preserved patch reefs. The description of these
bodies (coral and algae bafflestone, bryozoan bafflestone and algal boundstone), and of a low relief mound reef
(skeletal algal packstone) are presented in this paper. The associated facies are represented by low energy deposits
(mudstone), bar complexes (sandy skeletal packstone and skeletal packstone) and channels (skeletal intraclast
floatstone and intraclast skeletal ooidal floatstone).