000			02116nab a2200205 4500
005			20260520002931.0
008			260224s2010 xxu
245	0	0	_aGeochemical study of natural CO2 emissions in the french massif central: how to predict origin, processes and evolution of CO2 leakage
260			_a _b _cmayo/jun. 2010
270			_a31/08/2010 ; 31/08/2010
300			_a20 p. ; 615-634
520			_aTranscripción del resumen del autor. This study presents an overview of some results obtained within the French ANR (National Agency of Research) supported Géocarbone-Monitoring research program. The measurements were performed in Sainte-Marguerite, located in the French Massif Central. This site represents a natural laboratory for CO2/fluid/rock interactions studies, as well as CO2 migration mechanisms towards the surface. The CO2 leaking character of the studied area also allows to test and validate measurements methods and verifications for the future CO2 geological storage sites. During these surveys, we analyzed soil CO2 fluxes and concentrations. We sampled and analyzed soil gases, and gas from carbo-gaseous bubbling springs. A one-month continuous monitoring was also tested, to record the concentration of CO2 both in atmosphere and in the soil at a single point. We also developed a new methodology to collect soil gas samples for noble gas abundances and isotopic analyses, as well as carbon isotopic ratios. Our geochemical results, combined with structural geology, show that the leaking CO2 has a very deep origin, partially mantle derived. The gas rises rapidly along normal and strike-slip active faults. CO2 soil concentrations (also showing a mantle derived component) and CO2 fluxes are spatially variable, and reach high values. The recorded atmospheric CO2 is not very high, despite the important CO2 degassing throughout the whole area.
581			_a4
773	0		_tOil and Gas Science and Technology _g65
942			_cARTICULO
100	1		_aBattani, A. _946755
100	1		_aDeville, E. _946756
100	1		_aFaure, J.-L. _933454
999			_c176592 _d176592