X-ray diffraction of clay grain-size fraction of sediments, organic matter optical analysis and micro-thermometric study of fluid inclusions are widely used in oil exploration for determining the thermal maturity of sedimentary successions and basin evolution (from tens to hundred million years) by means of thermal modelling (ROURE et alii, 2010). The quantitative investigation of organic matter physico-chemical variations by optical measurements (e.g., vitrinite reflectance), of clay minerals structural and compositional changes (e.g., mixed layer illite-smectite) by X-ray diffraction and of microthermometry recorded by fluid inclusions (e.g., Th and Tm) allows to determine the thermal maturity of sediments, from diagenesis to very low-grade metamorphism, and to constrain the maximum temperatures experienced by rocks (e.g., MAZZOLI et alii, 2008). As a matter of fact this multi-method approach is much less applied to detect paleo-temperatures in fossil and active geothermal systems, despite the validity of the single techniques has been tested in several case histories of geothermal interest to characterise modes of fluid-rock interaction and abnormally high geothermal gradients at shallow crustal levels (ALDEGA et alii, 2010). In the last year, we have been fully developing this integrated methodology to reconstruct the thermal evolution of Rosario de La Frontera active geothermal system (ESPELTA et alii, 1975), located in the Santa Barbara System, in NW Argentina in the foothills of the Cordillera. In this contribution we present the preliminary analytical and modelling results concerning the paleo-thermal conditions recorded by the sedimentary succession cropping out along La Candelaria Ridge that hosts the aforementioned system.
Modelling of organic and inorganic paleo-thermal indicators to constrain the evolution of the geothermal system of Rosario de La Frontera (La Candelaria Ridge, NW Argentina): a new tool for geothermal exploration
INVERNIZZI, Maria Chiara
2012-01-01
Abstract
X-ray diffraction of clay grain-size fraction of sediments, organic matter optical analysis and micro-thermometric study of fluid inclusions are widely used in oil exploration for determining the thermal maturity of sedimentary successions and basin evolution (from tens to hundred million years) by means of thermal modelling (ROURE et alii, 2010). The quantitative investigation of organic matter physico-chemical variations by optical measurements (e.g., vitrinite reflectance), of clay minerals structural and compositional changes (e.g., mixed layer illite-smectite) by X-ray diffraction and of microthermometry recorded by fluid inclusions (e.g., Th and Tm) allows to determine the thermal maturity of sediments, from diagenesis to very low-grade metamorphism, and to constrain the maximum temperatures experienced by rocks (e.g., MAZZOLI et alii, 2008). As a matter of fact this multi-method approach is much less applied to detect paleo-temperatures in fossil and active geothermal systems, despite the validity of the single techniques has been tested in several case histories of geothermal interest to characterise modes of fluid-rock interaction and abnormally high geothermal gradients at shallow crustal levels (ALDEGA et alii, 2010). In the last year, we have been fully developing this integrated methodology to reconstruct the thermal evolution of Rosario de La Frontera active geothermal system (ESPELTA et alii, 1975), located in the Santa Barbara System, in NW Argentina in the foothills of the Cordillera. In this contribution we present the preliminary analytical and modelling results concerning the paleo-thermal conditions recorded by the sedimentary succession cropping out along La Candelaria Ridge that hosts the aforementioned system.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
