Sedimentary evolution and depositional architecture of a Lowstand Sequence Set: The Lower Cretaceous Mulichinco Formation, Neuquén Basin, Argentina

Producción CyT

Capítulo de Libro

Autoría

SCHWARZ, ERNESTO

Fecha

2005

Editorial y Lugar de Edición

Geological Society, London, Special Publications

Libro

The Neuquén Basin, Argentina: a case study in Sequence Stratigraphy and Basin Dynamics (pp. 109-138)
Geological Society, London, Special Publications

ISBN

1-86239-190-4

Resumen Información suministrada por el agente en SIGEVA

The Valanginian Mulichinco Formation was accumulated in the Neuquén Basin (west-central Argentina), during and immediately after a major relative sea–level fall, partially triggered by a tectonic inversion pulse. The Formation represents a lowstand wedge where excellent outcrops together with refined biostratigraphic coverage have permitted the detailed examination of contemporaneous non-marine and marine deposits. Fourteen facies associations were identified in the Mulichinco Form... The Valanginian Mulichinco Formation was accumulated in the Neuquén Basin (west-central Argentina), during and immediately after a major relative sea–level fall, partially triggered by a tectonic inversion pulse. The Formation represents a lowstand wedge where excellent outcrops together with refined biostratigraphic coverage have permitted the detailed examination of contemporaneous non-marine and marine deposits. Fourteen facies associations were identified in the Mulichinco Formation. They represent accumulation ranging from gravelly fluvial braidplains to outer-shelf marine settings. Distribution of depositional environments, together with the identification of key surfaces and stratal patterns, has resulted in the identification of early and late lowstand, transgressive, and highstand system tracts. Accordingly, the Mulichinco lowstand wedge comprises one third-order sequence that lasts about 2 m.y. and represents a lowstand sequence set. Shoreline sedimentation was remarkably different in certain areas of the Mulichinco depositional area and alluvial deposits were not developed within incised valleys. Tectonically-derived topography, basin physiography, and fault-controlled subsidence are interpreted to have been the main controls on the evolution of the Mulichinco lowstand wedge. The results of this study have important implications for both understanding the history of Neuquén Basin and illustrating the previously undocumented architectural complexity that may exist within lowstand wedges.

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Palabras Clave

LOWSTAND WEDGESEDIMENTARY EVOLUTION AND ANATOMYFORMACION MULICHINCONEUQUÉN BASIN