tesis de doctorado.page.titleprefix Análisis de la evolución tectosedimentaria del ciclo precuyano en la sierra de la Cara Cura, cuenca neuquina, Mendoza con énfasis en su potencial hidrocarburífero
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Date
2018
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Abstract
"En la región de la Sierra de la Cara Cura, provincia de Mendoza, aflora una serie triásica superior-jurásica temprana asociada al hemigraben más septentrional de la cuenca Neuquina surmendocina. Este ha sido identificado como Cara Cura-Reyes y reúne los estadios iniciales del relleno de la cuenca conformados por los depósitos del Ciclo Precuyano.
La sedimentación inicial fue continental, volcaniclásticas a volcánica y en menor proporción epiclástica y tuvo lugar en hemigrábenes asimétricos con polaridad sudoeste. El margen activo corresponde a la zona del río seco de la Aguada del Altar. La evolución del relleno estuvo marcada por un fuerte control tectónico y volcánico que le imprimieron a las secuencias rasgos distintivos, y permitieron dividirla en dos estadios de rifting. El primero o Rift I, asociado a los depósitos del Ciclo Precuyano incluyendo a la Formación Remoredo, mientras que en el Rift II, se ubicarían las rocas del Grupo Cuyo.
El análisis petrográfico permitió determinar las características composicionales y las de alteraciones presentes en el relleno. El estudio geoquímico reveló un rango continuo composicional desde andesitas basálticas hasta dacitas, con características comagmáticas, tendencia subalcalina-calcoalcalina y patrones de elementos trazas asociados a una pluma mantélica fría. Las rocas del Ciclo Precuyano estarían asociadas a un ambiente geotectónico de transición, entre margen continental activo y uno de intraplaca, generadas en una corteza de espesor normal.
Teniendo en cuenta las características genéticas y formacionales de las unidades depósitacionales y su relación espacial, se identificaron tres secciones dentro de los depocentros que fueron correlacionadas entre los depocentros de Cara Cura y Reyes.
El estudio petrofísico permitió identificar el tipo de porosidad (primaria vs secundaria), los valores de porosidad y permeabilidad de las litofacies identificadas así como que factores los controlaron. Esto permitió asociar a los depósitos del Ciclo Precuyano con reservorios de tipo carbonáticos fracturados."
"In the Sierra de la Cara Cura region, Mendoza province, a series of Upper Triassic-Early Jurassic rocks corresponding to the infilling of the northernmost hemigraben of the Neuquén basin, crops-out in the southern Mendoza portion. These rocks encompass volcaniclastic and epiclastic facies which represent a significant volcanic and sedimentary event occurred during that time interval. The corresponding depocenter has been identified as Cara Cura–Reyes. Continental, volcanoclastic and epiclastic sedimentation took place in isolated depocenters which built an asymmetric halfgraben with its deepest portion to southwest, in the de la Aguada del Altar Dry River. The tectonic and volcanic controls on these sequences are represented in the type of volcanic environments and quantity and characteristics of the clastic material provided to the depocentres. The evolution of the sinrift infilling can be subdivided into two rifting stages (rift I and ll). Rift I, associated with the Precuyano Cycle and the Remoredo Formation, Rift II, that includes the Cuyo Group rocks. The geochemical signature of the volcanic and volcanoclastic rocks was studied trough the analysis of thin sections and chemical analyses of major, minor and trace elements. As a result, continuous ranges from basaltic andesitic to dacites with co-magmatic and sub-alkaline to calc-alkaline affinities were determined for these volcanic rocks. The rocks of the Precuyano Cycle were building up in a transitional environment, between continental active margin and intraplaca, developed in a normal continental crust. The infill of the sinrift sequence was divided into three depositional sections which were correlated between the Cara Cura and Reyes depocenters. The Precuyano Cycle, are composed of rocks with primary and secondary porosity. The values of porosity and permeability of the lithofacies identified as well as what factors controlled them, allowed associating the deposits of the Precuyano Cycle with fractured carbonate reservoirs."
"In the Sierra de la Cara Cura region, Mendoza province, a series of Upper Triassic-Early Jurassic rocks corresponding to the infilling of the northernmost hemigraben of the Neuquén basin, crops-out in the southern Mendoza portion. These rocks encompass volcaniclastic and epiclastic facies which represent a significant volcanic and sedimentary event occurred during that time interval. The corresponding depocenter has been identified as Cara Cura–Reyes. Continental, volcanoclastic and epiclastic sedimentation took place in isolated depocenters which built an asymmetric halfgraben with its deepest portion to southwest, in the de la Aguada del Altar Dry River. The tectonic and volcanic controls on these sequences are represented in the type of volcanic environments and quantity and characteristics of the clastic material provided to the depocentres. The evolution of the sinrift infilling can be subdivided into two rifting stages (rift I and ll). Rift I, associated with the Precuyano Cycle and the Remoredo Formation, Rift II, that includes the Cuyo Group rocks. The geochemical signature of the volcanic and volcanoclastic rocks was studied trough the analysis of thin sections and chemical analyses of major, minor and trace elements. As a result, continuous ranges from basaltic andesitic to dacites with co-magmatic and sub-alkaline to calc-alkaline affinities were determined for these volcanic rocks. The rocks of the Precuyano Cycle were building up in a transitional environment, between continental active margin and intraplaca, developed in a normal continental crust. The infill of the sinrift sequence was divided into three depositional sections which were correlated between the Cara Cura and Reyes depocenters. The Precuyano Cycle, are composed of rocks with primary and secondary porosity. The values of porosity and permeability of the lithofacies identified as well as what factors controlled them, allowed associating the deposits of the Precuyano Cycle with fractured carbonate reservoirs."
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GEOLOGIA, ESTRATIGRAFIA, PETROLOGIA, ROCAS, HIDROCARBUROS, REOLOGIA, YACIMIENTOS PETROLIFEROS