Strontium and sulfur isotope geochemistry of the Galeana Barite district, Nuevo Leon, Mexico

Sulfur and strontium isotope analyses have been used to test the possibility that barite veins in the Galeana district of northeastern Mexico formed where barium-bearing solutions intersected an overlying gypsum-bearing unit. Barite at Galeana occurs in essentially monomineralic veins in red beds of the Mesozoic-age Huizachal Group at and just below its contact with gypsum of the Olvido Formation. Sulfur isotope analyses confirm that the sulfur in the barite (δ³⁴S = 12.3-17.4‰) has the same range as Olvido gypsum (13.1-17.6‰) Solubility calculations and data on barium and strontium contents of formation waters indicate that a fluid volume of about 10¹¹ m³ would be required if the mineralizing solution contained about 100 ppm barium. -from Authors