Abstract:
In order to understand the protolith of the highly metasomatized rock, a substantial amount of the GCB matrix, avoiding the networks of veins is taken for major and trace element analyses. Bulk chemical analyses of the studied rocks illustrate that the GCB contain low SiO2 (44-45 wt%), comparatively high ferromagnesian content (18-21 wt%), significantly low amount of lime and alkalis (CaO+Na2O+K2O~2 wt%) and considerably high amount of alumina (>29 wt%).Normalized whole-rock trace element pattern shows a mild depletion in Ba, Sr and Pb whereas Ga, Cr and HFSEs such as Zr, Nb and Ta are enriched relative to primitive mantle values. Chondrite-normalized REE spider diagram, from whole-rock chemistry data, exhibits slight enrichment in LREE (10-100 times the chondrite value; LaCN/LuCN~4-15), no discernible europium anomaly (Eu/Eu*~0.7-0.9) and flat HREE pattern.
User Contributed Keyword(s):
Whole-rock chemical analysis, metasomatism, protolith identification