CIG   05423
CENTRO DE INVESTIGACIONES GEOLOGICAS
Unidad Ejecutora - UE
artículos
Título:
Depositional controls on mixed carbonate-siliciclastic cycles and sequences on gently inclined shelf profiles ? the Picún Leufú ? Vaca Muerta System in Neuquén Basin, Argentina.
Autor/es:
ZELLER, M.; VERWER, K.; EBERLI, G.; MASSAFERRO, J.L.; SCHWARZ, E. Y SPALLETTI, L.
Revista:
SEDIMENTOLOGY
Editorial:
WILEY-BLACKWELL PUBLISHING, INC
Referencias:
Lugar: Londres; Año: 2015 vol. 62 p. 2009 - 2037
ISSN:
0037-0746
Resumen:
The interplay between carbonate production and siliciclastic input producesmixed systems that typically contain a very high degree of lateral and verticalfacies heterogeneity. This heterogeneity complicates the sequence stratigraphicanalysis of mixed systems. Outcrop studies facilitate the decipheringof controls and understanding of facies distributions within sedimentary successions.The Picun Leufu Anticline in the Neuquen Basin (Argentina) offersthe opportunity to integrate large-scale depositional architecture withdetailed facies descriptions of the shelf to basin successions of the UpperJurassic ? Lower Cretaceous Quintuco ? Picun Leufu ? Vaca Muerta System.The strata in the system are mixed and range in depositional environmentsfrom shallow marine sandstones and limestones to deep basinal shales. Theseenvironments are arranged in metre-scale shallowing upward cycles andcycle sets, with increasing carbonate proportions in regressive hemicycles.Increased input of siliciclastic material from the volcanic arc area occurredduring phases of relative sea-level rise and was controlled by the intensity ofalong-shelf currents. The shelf transport was driven by the available accommodation space on the shelf, and therefore was a function of the eustatic sealevel fluctuations. Within the studied section, a pure carbonate depositionalsystem developed because siliciclastic input was shut down either due tolong-lived highstand settings or a sudden climatic change to more arid conditions. Carbonate?siliciclastic mixing in this setting is a function of siliciclastic dilution of the carbonate sedimentation and differs from the classical reciprocal sedimentation model, which typically includes shut-off of carbonate production during lowstand periods. In the regional context, the subsurface strata of time-equivalent reservoirs in the Eastern Neuquen Embaymentdisplay strong similarities of architecture, indicating that similar mixing processes occurred along most of the Neuquen Basin.