Abstract
Honvang serpentinite body (HSB) of the Song Ma fault zone, Nothern Vietnam is an elongate body with an area of 2 x 4 km, consisting mainly of massive serpentinite and fine-grained gabbro with rare chromitite. The Serpentinite preserves relict chromian spinel with rare olivine inclusions. The compositional relationship between the Fo content of olivine (Fo90-92) and Cr/(Cr+Al) atomic ratio (YCr) of chromian spinel (0.43-0.44) suggests that the original peridotite was spinel-bearing lherzolitic harzburgite. We suggest that the serpenitinite body represents a remnant of paleo-oceanic lithosphere between the Indochina and South China blocks.
