Articulo
Copper geochemistry in salt from evaporite soils, coastal range of the atacama desert, northern chile: an exploration tool for blind cu deposits
GEOCHEMISTRY-EXPLORATION ENVIRONMENT ANALYSIS;
Geochem.-Explor. Environ. Anal.
Registro en:
0
D01I1012
D01I1012
WOS:000233038500008
1467-7873
Autor
LAHSEN-AZAR, ALFREDO
GUERRA-SEPULVEDA, NELSON
TOWNLEY-CALLEJAS, BRIAN
PARADA-REYES, MIGUEL
PALACIOS-MONASTERIO, CARLOS
Institución
Resumen
The evaporite soil (1.5 to 15 m thick) in the Coastal Range of northern Chile is a serious obstacle to mineral exploration. We conducted a Cu geochemical study in salt beds (mainly gypsum and anhydrite) from this soil. The sampling was distributed over mineralized and barren rocks, in salts of evaporitic soils from hills, slopes, gullies, plains and alluvium-filled valleys. The samples of salt from hills and slopes reflect very well the presence of blind ore deposits, and the magnitude of the Cu anomalies ( < 200 to > 1000 ppm Cu) is independent of the depth at which the mineralization is located. Similar geochemical response has been found in salt from evaporitic sods that cover gullies, plains and alluvium-filled valleys. However, in the last case the magnitude of the Cu anomalies ( < 20 to > 200 ppm Cu) depends on the thickness of the gravels and the depth of leached bedrock that covers the blind deposits. Although the Cu anomalies are spiky, their contrast with the back-ground Cu population is remarkable. Sampling of salt from evaporitic soils appears to be a valuable tool for exploration of buried Cu deposits in the exceedingly and Coastal Range of the Atacama Desert. 0 16 FONDEF cpalacio@cec.uchile.cl; nguerra@ucn.cl; btownley@cec.uchile.cl; alahsen@cec.uchile.cl; maparada@cec.uchile.cl 0 FONDEF 5