Sedimentological and ichnological characterization of muddy storm related deposits: The upper Hauterivian ramp of the Agrio Formation in the Neuquén Basin, Argentina

COMERIO, MARCOS; FERNÁNDEZ, DIANA ELIZABETH; PAZOS, PABLO JOSÉ

CRETACEOUS RESEARCH (PRINT)

ACADEMIC PRESS LTD-ELSEVIER SCIENCE LTD

Año: 2018 vol. 85 p. 78 - 94

0195-6671

The lowermost part of the Agua de la Mula Member (upper Hauterivian), Agrio Formation, was studied in distal depositional settings at four locations in the central Neuquen Basin. Detailed sedimentological and ichnological analysis combining field data and microfacies, using petrography, X-ray diffraction, andorganic geochemical data allow to recognize two facies associations, representing proximal to distal facies of a mixed, carbonate-siliciclastic homoclinal outer ramp. The distal outer ramp facies association (FA-1) contains mudstones accumulated by suspension settling during periods of high productivity in the water column with calcareous microfossils as fecal pellets and organo-minerallic aggregates. Very thin (