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On the genetic classification and tectonic implications of the Early Yanshanian granitoids in the Nan ling Range, South China.
- Source :
-
Chinese Science Bulletin . Jul2007, Vol. 52 Issue 14, p1873-1895. 23p. 1 Chart, 8 Graphs. - Publication Year :
- 2007
-
Abstract
- Early Yanshanian (Jurassic) granitoids are widespread in the Nanling Range of South China, and are associated with numerous non-ferrous and rare metal mineral deposits. These granitoids consist mainly of slightly peraluminous biotite monzogranites and K-feldspar granites that are closely associated in time and space with subordinate amphibole-bearing granites and muscovite- and garnet-bearing granites. In most previous studies, the biotite-bearing granites were classified as crustal transformation-type (corresponding to the S-type) granites which were interpreted to be derived from the regional Paleoproterozoic meta-sedimentary rocks. In this paper, we re-analyze the geochemical characteristics of a number of representative Early Yanshanian Nanling granitoids. There exists a clear negative correlation between SiO2 and P2O5 for the studied granitoids. The Early Yanshanian Nanling granitoid suites (including amphibole-bearing granodiorites→biotite monzogranites→K-feldspar granites→two-mica (muscovite) granites) are metaluminous to slightly peraluminous I-type or fractionated I-type granites. They were derived predominantly from Proterozoic igneous protoliths. The juvenile crust and/or newly mantle-derived materials might also have been involved in some of these granites. In addition, the I- and fractionated I-type granites are closely associated in time and space with minor amount of A-type felsic and mafic volcanic and intrusive rocks as well as alkaline rocks. All these rocks constitute a typical assemblage of anorogenic, intraplate magmatism, suggesting a dominant lithospheric extensional regime for the Nanling Range and neighboring region during the Early Yanshanian period. [ABSTRACT FROM AUTHOR]
- Subjects :
- *GRANITE
*IGNEOUS rocks
*GENETICS
*CLASSIFICATION
Subjects
Details
- Language :
- English
- ISSN :
- 10016538
- Volume :
- 52
- Issue :
- 14
- Database :
- Academic Search Index
- Journal :
- Chinese Science Bulletin
- Publication Type :
- Academic Journal
- Accession number :
- 26546837
- Full Text :
- https://doi.org/10.1007/s11434-007-0259-0