文献类型：期刊文献

英文题名：The initial magma-fluid evolution of the Laochang porphyry molybdenum deposit in Lancang, Yunnan, SW China: Insights from the in-situ analysis of mica and titanite

作者：Zhang, Ying-Ying Luo, Tai-Yi Fan, Yun-Fei Long, Han-Sheng Yang, Yong Yang, Jin-Biao Meng, Fu-Qing

第一作者：Zhang, Ying-Ying

通信作者：Luo, TY[1]

机构：[1]Chinese Acad Sci, Inst Geochem, State Key Lab Ore Deposit Geochem, Guiyang 550081, Peoples R China;[2]Univ Chinese Acad Sci, Beijing 100049, Peoples R China;[3]Inst Nucl Resources Geol Survey, Nonferrous Met & Nucl Ind Geol Explorat Bur Guizho, Guiyang 550005, Peoples R China;[4]Guizhou Inst Technol, Sch Resources & Environm Engn, Guiyang 550003, Peoples R China;[5]Guizhou Univ, Min Coll, Guiyang 550025, Peoples R China;[6]Yunnan Lancang Lead Mine Co Ltd, Lancang 665601, Peoples R China

第一机构：Chinese Acad Sci, Inst Geochem, State Key Lab Ore Deposit Geochem, Guiyang 550081, Peoples R China

通信机构：corresponding author), Chinese Acad Sci, Inst Geochem, State Key Lab Ore Deposit Geochem, Guiyang 550081, Peoples R China.

年份：2024

卷号：265

外文期刊名：JOURNAL OF ASIAN EARTH SCIENCES

收录：;Scopus(收录号：2-s2.0-85187979378);WOS:【SCI-EXPANDED(收录号:WOS:001288981500001)】；

基金：This study was supported by the National Natural Science Founda-tion of China (41873058) . We are grateful to anonymous reviewers for reviewing this manuscript and their insightful comments.

语种：英文

外文关键词：Titanite; In-situ U-Pb dating; The A vein; Geothermobarometer; Laochang porphyry Mo deposit; Lancang

摘要：The Laochang polymetallic deposit is the only large deposit in the Changning-Menglian Junction Zone. The deposit features by deep porphyry-skarn Mo-(Cu) and shallow vein Pb-Zn-(Ag) mineralization. Researches on the deposit have yielded extensive data, however, details about the initial evolution from magma to ore-forming fluid remain unclear. This study centers on the in-situ analysis of biotite from the porphyry, as well as phlogopite and titanite from the A vein, leading to the following insights: (1) The biotite geothermobarometer suggests the porphyry intruded in a moderate depth (2.57-4.27 km), with average parameters as P = 93 MPa, T = 697 degrees C, and logfO2 f O 2 =-16.78. (2) The A vein in the deposit can be further subdivided into A1 K-feldspar vein and A2 quartz vein. The phlogopite in the A1 vein formed at P = 98 MPa, T = 681 degrees C, and logfO2 f O 2 =-17.29. The pressure of the A1 vein is slightly higher than the static pressure of wall rock, attributed to pressure increment from the initial exsolved fluid. Conversely, the temperature and oxygen fugacity experience a slight decrease, due to buffering of the adjacent tuff. (3) The in-situ LA-ICP-MS U-Pb dating of the titanite in the A1 vein yields 44.4 +/- 1.5 Ma (MSWD = 1.8, n = 48), comparable to the emplacement age of the porphyry (44.6-44.4 Ma). It is slightly older than the main mineralization age (43.78 Ma), further delineated the initial evolution sequence from magma to ore-forming fluid. Our research suggests that the in-situ analysis of titanite is crucial for preciously tracking the magma-fluid system, as titanite records both time and temperature information.