Property and metallogenic characteristics of alkali-rich porphyry in western margin of Yangtze Platform

Abstract

The age of alkali-rich porphyries in the western margin of Yangtze Platform is 30–50 Ma; the minerals mainly are orthoclase, quartz, plagioclase; the chemical composition is alkali-rich [(K₂O+Na₂O)>8%], highpotash[(K₂O+Na₂O)=5.09%−8.30%]; the content of ΣREE is relatively low, LREE is concentrated, without anomaly of europium; the average initial ratio of ⁸⁷Sr/⁸⁶Sr is 0.7073; the value of δ³⁴S similar to that of the meteoritic sulfur; the ratio of Pb isotope corresponds to that of upper mantle; metallogenic types belong to Cu, Mo, Au, Ag, Pb, Zn polymetal mineralization and rare, rare-earth metal mineralization.

Keywords

petrology / geochemistry / alkali-rich porphyry / metallogenic characteristics

References

[1] TuGuangzhiTuGuangzhi. The preliminary study of two alkali-rich intrusive bodies in Southern China. Collection of Papers of Nanjing Symposium for the Origin of International Granite, 1984, Beijing, Science Press: 1-8(in Chinese)

[2] ZhangYunan, TuGuangzhi. The preliminary study of the relation between alkali-rich intrusive body in Ailaoshan-Jinshajiang and rift valley structure. Lithological Journal, 1987, 5(1): 17-17(in Chinese)

[3] HuXiangzhao. The origin of alkali-rich granite porphyry in Western Yunan Province. Journal of Chinese Nonferrous Metal, 1995, 4(1): 1-1(in Chinese)