Meso- and Neoproterozoic mafic-ultramafic rocks from northern Guangxi have been dominantly classified as calc-alkaline series. The mafic rocks have Nb/Lapm = 0. 13 ∼ 0. 51, Th/Lapm = 0. 85 ∼ 3. 3, Ti/Ti° = 0. 29 ∼ 0. 61 and show negative Nb and Ti anomalies in primitively mantle normalized patterns. The Meso-proterozoic mafic rocks share lower εNd (t) than those of Neoproterozoic, i. e. - 1. 99 ∼ - 5. 13 vs. - 0. 74 ∼ 2.4 respectively. They together show geochemical features of island arc volcanic series and thought to be the products of magmatism of convergent plate boundary rather than derived from mantle plume. Therefore, they be couldn't considered as a indicator of breakup of Rodinia supercontinent.
|Number of pages||10|
|Journal||Acta Petrologica Sinica|
|Publication status||Published - 2003|
- Mafic-ultramafic rocks
- Meso- and Neoproterozoic
- Northern Guangxi