Occurrence of dravitic tourmaline in a diamond-bearing breccia: a possible lamproite deposit in the Alto Paranaíba Igneous Province

The mineral chemistry of diamond indicator minerals is used to trace mineralizations in primary rocks such as lamproites/kimberlites and secondary deposits. Subcalcic garnets magnesian ilmenites are both associated with the potential described many deposits Alto Paranaíba Igneous Province where several kimberlitic pipes alluvial occur. Our study was conducted on Romaria deposit (Brazil), garnet, ilmenite tourmaline grains were recovered from a diamon-bearing breccia analyzed under electron microprobe. garnet composition compatible G10, G9 G5 types. Ilmenite Mg- Mn-rich. Nearly 80% dravite-type. This association dravite lamproitic affinity may be common, evidenced Argyle, Ellendale, Prairie Creek, Sask, Presidente Olegário Ymi-1 pipes. We therefore suggest possible lamproite origin for studied deposit.