Dolomitized tidal cycles in the Agua de la Mula Member of the Agrio Formation (Early Cretaceous), Neuquén Basin, Argentina

TUNIK, MAISA ANDREA; PAZOS, P; IMPICCINI, A; LAZO, D; AGUIRRE-URRETA, M.B

Latin american Journal of Sedimentology and Basin Analysis

Asociación Argentina de Sedimentología

Año: 2009 vol. 16 p. 29 - 43

1669-7316

The Agrio Formation is a siliciclastic and carbonate unit of the Neuquén Basin in west central Argentina. A conspicuous dolomitization level was identified near the top of the upper Member of the Agrio Formation. The analyzed section is composed of dolostones with scarce siliciclastic intercalations. A tidal flat environment with high frequency cycles was suggested for the measured. The dolomitization process that affected the unit has been different if it was produced on subtidal facies or in intertidal facies. On the subtidal facies the dolomitization was mimetic on the ooids and on some bioclasts and it is characterized by the presence of dolomite cementation. On the other hand, the dolomitization processes on the intertidal facies generate mimetic dolomitization on the ooids, on some bioclasts and on the early marine cement without dolomite cementation. The proposed dolomitization model for this section is the shallow seawater dolomitization model.