Estuarine and shallow marine sedimentation in the Upper Cretaceous - Lower Tertiary west-central Patagonian Basin

SPALLETTI, L. A.

Geology of Siliciclastic Shelf Seas

Geological Society

Lugar: Londres; Año: 1996; p. 81 - 93

The Upper Cretaceous - Paleocene Paso del Sapo - Lefipán Basin is an intracratonic depocentre located to de east of the Andean magmatic arc. The sedimentary infill comprises two stratigraphic units. The Campanian-Maastrichtian Paso del Sapo Fm is mainly composed of sandstones and conglomerastes associated with minot heterolithic intervals, mudstones and coal beds. The Maastrichtian-Paleocene Lefipán Fm is composed of gypsiferous mudstones and shales with isolated x-bedded sandstones; these depostis transitionally pass to x-bedded sandstones and coquina beds. Sedimens of the PSF show features of fluvial and tidal influenced systems. Most of the LF was formed under open marine conditions. The transgressive sedimentary record is in the range of a second-order eustatically controlled cycle (retrogradationl systems tract).