A large number of spilitic and mafic-ultramafic rocks exist in the Longsheng region of northern Guangxi. These rocks were previously considered as th "Longsheng Ophiolite". Comprehensive investigations of field geology, petrology 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 rocks of Danzhou Group. The spilites, interlayed within the Neoproterozoic Danzhou 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 environment with various degrees of crust contamination. Thus, the spilites and mafic-ultra mafic intrusives in the Longsheng region are not part of a "ophiolite complex", but the products of mantle-derived magma generated during the evolution of the Neoproterozoic Nanhua rift.
|Journal||Acta Petrologica Sinica|
|Publication status||Published - 2000|