Petrology and geochemistry of the Silgara Schists in the Silos area, Santander Massif, Colombia

Abstract

The Silgará Schists consist of metapelites, metasemipelites, quartz-feldspathic rocks, pure carbonate rocks and calcsilicate rocks. The REE content and patterns, the Zr/Sc and Th/Sc ratios, and the high contents of Hf and Zr point to a felsic upper crustal source with a high degree of recycling. The Silgará Schists were metamorphosed at peak conditions of 670 – 770° C and 7.8 – 11.3 Kbar as indicated by the paragenesis Bt + Grt + St + Qz + Ky + Pl. The lithology and P-T conditions of the Barrovian type metamorphism of the Silgará Schists of the Silos stripe is very similar to those from the Mutiscua area.