"Longsheng Ophiolite" in North Guangxi revisited.

A large number of spilitic and mafic-ultramafic rocks exist in the Longshen g region of northern Guangxi. These rocks were previously considered as th "Longsheng Ophiolite". Comprehensive investigations of field geology, petro logy and geochemistry for these rocks were carried out in this study. Mafic -ultramafic rocks are dominantly gabbros and serpentinized olivine gabbros and olivine pyroxenolites. They show intrusive contacts with the country ro cks of Danzhou Group. The spilites, interlayed within the Neoproterozoic Da nzhou Group (less than or equal to 820 Ma), are geochemically characterized by enrichment of most incompatible trace elements but depletion of Nb, Ta and Ti, indicating that they were likely generated within an intraplate env ironment with various degrees of crust contamination. Thus, the spilites an d mafic-ultra mafic intrusives in the Longsheng region are not part of a "o phiolite complex", but the products of mantle-derived magma generated durin g the evolution of the Neoproterozoic Nanhua rift.