Petrogenesis of the Maogongdong highly differentiated granite in the Dahutang tungsten ore field, Jiangxi Province

Chen，Wei1; Chen，Bin2; Sun，Ke Ke3

2018

ACTA PETROLOGICA SINICA   影响因子和分区

1000-0569

2095-8927

The Dahutang tungsten (molybdenum, copper, tin) ore fields are located in the middle segment of the Jiangnan orogen, northern part of Jiuling batholith, which is the largest tungsten mine in the world. The Maogongdong granite pluton occurs in the southern part of the Dahutang tungsten ore field, composed of porphyritic granite and muscovite granite with tungsten mineralization. In this paper, we reported detailed studies on the LA-ICP-MS zircon U-Pb dating, major and trace elements, in-situ mica LA-ICPMS trace elements and the whole-rock Nd isotopie compositions of the two rock types. The results show that zircon U-Pb dating of the porphyritic granite yields an age of 132. 5 ±1.8 Ma, and the muscovite granite was emplaced later according to the field investigation. Petrography and geochemical data indicate that muscovite granite is a highly evolved in comparison with the porphyritic granite, and is characterized by high silica and alkalis, low Ga/Al ratios, high Rb/Sr, weak LREE/HREE fractionation, pronounced negative Eu anomalies, REE tetrad effect, and modified behavior of trace elements (non-CHARAC). The muscovite granite has ssd values (-5.4 ∼ +2.5) higher than the porphyritic granite (-7. 5 ∼ -5. 9). We suggest that the porphyritic granite was derived from melting of the Shuangqiaoshan Group meta-sediments, leaving behind in the lower crust a granulitic residue, and the highly differentiated muscovite granite formed by re-melting of the residue, triggered by the underplating of a new pulse of basaltic magma. Underplating of basaltic magma provides not only the high temperature required for melting the residue but also the volatile (fluorine, boron) in the source of the granite. Addition of fluorine and boron lowered the solidus temperature and the viscosity of granite magma, and thus prolonged the process the magma evolution. This appears to have resulted in extreme fractional crystallization and intense interaction between melt and circulating waters from country rocks, forming the unusual geochemical features of the granite and subsequently extract ore-forming metal from the country rocks, forming the polymetallic deposits.

Dahutang tungsten ore field Geochemistry Highly differentiated granite Jiangxi Province Nd isotope REE tetrad effect

EI

英语

其他

20190306395906

Mineralogy ; Boron ; Fluorine ; Geochronology ; Mass spectrometers ; Silica ; Trace elements ; Melting ; Ores ; Geochemistry ; Viscosity ; Binary alloys ; Lead alloys ; Mica ; Inductively coupled plasma mass spectrometry ; Isotopes ; Petrology ; Zircon

Geology:481.1 ; Petrology (Before 1993, use code 482):481.1.2 ; Geochemistry:481.2 ; Geophysics:481.3 ; Mineralogy:482 ; Minerals:482.2 ; Gems:482.2.1 ; Lead and Alloys:546.1 ; Nonferrous Metals and Alloys excluding Alkali and Alkaline Earth Metals:549.3 ; Fluid Flow, General:631.1 ; Chemistry:801 ; Chemical Operations:802.3 ; Chemical Products Generally:804 ; Physical Properties of Gases, Liquids and Solids:931.2

GEOSCIENCES

2-s2.0-85060018829

Scopus

1.Key Laboratory of Orogenic Belt and Crustal Evolution,Peking University,Beijing,100871,China
2.Department of Earth and Space Sciences,Southern University of Science and Technology,Shenzhen,518055,China
3.State Key Laboratory of Geological Processes and Mineral Resources,China University of Geosciences,Beijing,100083,China

Chen，Wei,Chen，Bin,Sun，Ke Ke. Petrogenesis of the Maogongdong highly differentiated granite in the Dahutang tungsten ore field, Jiangxi Province[J]. ACTA PETROLOGICA SINICA,2018,34(6):1704-1724.

Chen，Wei,Chen，Bin,&Sun，Ke Ke.(2018).Petrogenesis of the Maogongdong highly differentiated granite in the Dahutang tungsten ore field, Jiangxi Province.ACTA PETROLOGICA SINICA,34(6),1704-1724.

Chen，Wei,et al."Petrogenesis of the Maogongdong highly differentiated granite in the Dahutang tungsten ore field, Jiangxi Province".ACTA PETROLOGICA SINICA 34.6(2018):1704-1724.