Estudio geoquímico de siete muestras de las formaciones fosfáticas del sur de Ia península de Baja California, México.

Abstract

Geochemical data are presented for seven samples of phosphorites and phosphatic sediments collected from the San Raymundo and San Gregorio Formations and one recent dune from the south of the Peninsula of Baja California. The average composition of the material analyzed (number of samples, n=7) is: P20s 30.5% (82.3% as apatite), organic matter (as lost on ignition) 2.0%, CaO 24.0%, Cd 12 ppm, Co 12 ppm, Cr 342 ppm, Cu 17 ppm, Mn 60 ppm, Ni 23 ppm, V 60 ppm and Zn 80 ppm. The geochemical relationships and variations reveal that the recent phosphatic sands may originate by erosion and redeposition of the phosphorites. The ratio Cu/Zn and levels of Mn suggest that the redox conditions of the formation environments were different for the phosphatic material studied.