PERSONAL DE APOYO
DAPEÑA Cristina
congresos y reuniones científicas
Título:
Environmental Isotopes and Geochemistry of Bañado Carilauquen. Mendoza, Argentina
Autor/es:
OSTERA, HECTOR; DAPEÑA, CRISTINA
Lugar:
Salvador-BA, Brazil
Reunión:
Simposio; IV South American Symposium on Isotope Geology; 2003
Institución organizadora:
Comité SSAGI Brazil
Resumen:
The environmental
impact of the industrial activities leads to a great concern about the
conservation of natural pristine resources. This objective confronts with a big
challenge: How we can determine the original environmental parameters before
the anthropic influence?
Moreover, in
petroleum fields the base levels of hydrocarbon concentration in waters and
soils have natural anomalies related to existence of oil reservoirs themselves.
Consequently, it is very complex to quantify the environmental impact of
petroleum exploitation and the influence of possible spills if previous base
studies were not made. Since 1930, the Llancanelo oil field, located at Malargüe,
Mendoza province, has been exploited and explored. Sulfurous waters and gas
manifestations were found near the mouth of the arroyo Carilauquen. The aim of
this study is to characterize the natural pristine conditions of the system by
means of geochemistry and environmental stable isotopes (2H and 18O) and also, a first
approach for the origin and circulation pattern of water.
Geochemistry and
isotope baseline study of Bañado Carilauquen indicate that there are two main
types of water in the area: sulfate-chloride-calcium type and subordinate
chloride-sulfate-sodium type. The sulfate contents are higher than limits
proposed by OMS. Hydrocarbon pollution was not detected. The main sources of
recharge for Carilauquen springs could be related to the Malargüe River
infiltration westwards owing the similarities on isotope composition. However,
it cannot discard some local meteoric recharge detected in groundwater. Mixing
processes due overexploitation are detected by geochemical modeling, but are
masked in the isotope signal. Lake waters show a marked isotope enrichment,
linked with evaporation processes. These environmental parameters establish the
natural geochemical and isotope background of this area, which fragile
equilibrium could be endangered by human activities.