Occurrence of supergene nickel ores in the Ha Tri Massive, Hoa An District, Cao Bang Province
Authors: Pho Nguyen Van , Xuan Pham Tich , Dang Pham Thanh 
Published: May 2018

Nickel (Ni) laterites are regolith materials derived from ultramafic rocks and play an important role in the world's Ni production. Ni-laterite deposits are the supergene enrichment of Ni formed from the intense chemical and mechanical weathering of ultramafic parental rocks. In Vietnam, the weathering profile containing Ni laterite was first discovered in the Ha Tri massive (Cao Bang). This profile develops on the Ha Tri serpentinized peridotite rocks classified to the Cao Bang mafic-ultramafic complex (North Vietnam) and exhibits thick weathered zone (10 - 15m). This work carried out a detailed study of the weathering profile at the center of Ha Tri massive. Samples from different horizons of the profile were collected and analyzed in detail by XRF, XRD and SEM-EDX methods to establish the relationship between the Ni-rich supergene products and the parental peridotites (lherzolite) rocks in Ha Tri massive. 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