Jurassic granitoid dike in Luodian, Guizhou Province: discovery and geological significance

• 作者: Mingjin Zhu Aiguo Nie Yazhou Tian Xinsong Wang Jun Sun
• 学科: 地球科学
• 关键词: Jurassic granitoid dike Geochemical characteristics Geochronology Luodian Guizhou province
• 年，卷（期）: 2022,（1）
• 页码范围: 159-172
• 页数: 13页
• 语种: 英文
• DOI: 10.1007/s11631-018-0308-1

摘要

In this paper, the Jurassic granitoid dike that intrudes into Permian diabase was reported in Luokun, Luodian County, south Guizhou. Zircon LA-ICP-MS U–Pb dating of the granitoid dike yielded an age of 164.3 ± 2.4 Ma with the eHf(t) range from + 7.8 to + 12.1. The high contents of SiO2 (65.2%–66.8%) and total alkali (Na2O + K2O: 9.01%–9.95%), and low contents of Mg, Fe, Ca, P and Ti show the characteristics of alkali-rich granite. The total contents of rare earth elements range from 289.90 to 394.23 ppm. The Rb, Ba, K, Th, U and other LILE, Ta, Sr, P, Ti are enriched, and heavy rare earth elements are depleted. Petrogeochemical characteristics show that the dike was derived from a partial melting of newly-grown basaltic crust, and contaminated by crustal materials before experiencing strong fractional crystallization. The dike was formed in the intraplate post-orogenic extension stage and indicates that parental magma rose to the shallow crust through a fault. This provides new evidence of tectonic and mantle-crust magmatic activities and may contribute to regional Au mineralization in southern Guizhou and neighboring areas.