Wang J.H.,Kunming University of Science and Technology |
Li W.C.,Kunming University of Science and Technology |
Wang K.Y.,Jilin University |
Yin G.H.,Yunnan Geological Survey |
And 2 more authors.
Acta Petrologica Sinica | Year: 2015
The Beiya super-large gold deposit is located in the junction zone of the 'Sanjiang' Tethys orogenic belt and Yangtze plate in SW China. This systematic study on fluid inclusion developed in the quartz phenocryst of porphyries and mainly mineralization (i. e. porphyry-, skarn-, and layer-like epithermal-) occur in the Beiya deposit indicate that there are six types of fluid inclusions exist in the study area named: I CO2 fluid inclusions; II CO2-rich fluid inclusions; III CO2-bearing fluid inclusions; IV halite-bearing three-phase fluid inclusions; V vapor-rich fluid inclusions and VI aqueous two-phase fluid inclusions; the ore forming fluids responsible for the formations of porphyry-, skarn-, and layer-like polymetallic epithermal-mineralizaion are medium to high temperature NaCl-H2O-CO2 type solutions, high temperature NaCl-H2O-CO2 with NaCl-H2O type solutions and medium temperature NaCl-H2O-CO2 type solutions respectively. The presence of vapor-rich fluid inclusions in the skarn demonstrates that vapor-rich ore forming fluids were differentiated from magma after the emplacement of the porphyries, and then came to the abundant of fluids rich in CO2. The fact that the groups of fluid inclusions in the porphyry- and layer-like polymetallic epithermal veins are almost the same to the ones in the quartz phenocrysts of porphyries indicates that the ore forming fluids related to the two types of mineralization came from the magmatic hydrothermal which differentiated from the central porphyries. This fluid inclusion study also iilustrates that the three main types of mineralization resulted from the evolution of the ore forming fluids diflerentiated from the magma which produced the alkaline-rich porphyries in Beiya constitute a porphyry Au-Fe-Cu-Pb-Zn-Ag polymetallic metallogenic system.
Hu S.X.,CAS Nanjing Institute of Geology and Palaeontology |
Zhu M.Y.,CAS Nanjing Institute of Geology and Palaeontology |
Steiner M.,Free University of Berlin |
Luo H.L.,Yunnan Geological Survey |
And 2 more authors.
Science China Earth Sciences | Year: 2010
The Guanshan biota from eastern Yunnan (Cambrian Series 2, early Stage 4) is a Burgess Shale-type fossil biota with abundant exceptionally preserved soft-bodied fossils after the discovery of the well-known Cambrian Chengjiang fauna and Kaili biota in South China. The geological settings, sedimentology, taphonomy, and the fossil assemblage of the Guanshan biota are briefly summarized here. The Guanshan biota consists of about 60 taxa belonging to more than 10 metazoan groups and algae, among which the lobopods, eldonids, hyolithids with helens, and green algae are reported for the first time. The common occurrence of soft-bodied preservation in many groups, notably the trilobites and brachiopods, makes the Guanshan biota a significant fossil lagerstätte for understanding the metazoan evolution during Cambrian explosion and taphonomy of the Burgess Shale-type fossils. © 2010 Science China Press and Springer-Verlag Berlin Heidelberg.
Li W.,Yunnan Geological Survey |
Li W.,Kunming University of Science and Technology |
Liu X.,Kunming University of Science and Technology
Earth Science Frontiers | Year: 2015
Geza arc is an important geological tectonic unit which formed in the Paleotethyan stage of the “Sanjiang” area in northwestern Yunnan. It is located in the southern tip of Yidun island-arc in the western margin of the Yangtze craton. In recent years, a series of deposits were newly found there, including the Pulang super-large sized copper deposit, Hongshan-Hongniu large sized copper deposit, Xuejiping large sized copper deposit, and more than 10 small and medium sized porphyry-skarn copper deposits, which constituted a porphyry copper orefield and a copper resources exploration and development base. The research found that the formation of ore deposits closely corresponded to the tectonic evolution, and different deposits were formed in different developmental stages. The regional NW-trending main faults corresponding to the tectonic evolution controlled the rock belts distribution, and the secondary faults and fold controlled morphology and occurrence of the rock mass. Porphyry deposit is mainly distributed in the core of the anticline and the emplacement depth of mineralized porphyry is shallow; skarn copper deposit was mainly produced in the core of the syncline and the emplacement depth of the porphyry was relatively deep. Most mineralized porphyries were composite pluton and often had a volcanic rock cover on the top of the composite pluton, which indicated that volcanic magmatic activity had the inherited characteristics. The formation of the Pulang super-large sized porphyry copper deposit was strictly controlled by the intersection of NW trending structure and NEE structure, it formed a “trinity” porphyry mineralization system which included porphyry copper deposit inside rock mass, skarn copper deposit of the contact zone and the large vein copper ore bodies in surrounding rocks, and also include the lead-zinc deposit and epithermal gold (silver) deposit in the outer contact zone. ©, 2015, Chinese Academy of Forestry. All right reserved.
Zhao H.-J.,China University of Geosciences |
Chen Y.-Q.,China University of Geosciences |
Lu Y.-X.,Yunnan Geological Survey
Geological Bulletin of China | Year: 2011
As an important part of the Tethyan metallogenic domain, Laos contains abundant mineral resources, especially rich Cu, Au, Fe, Al, and potash salt. Laos could exchange mineral advantages for economic advantages with China. The authors studied in detail the ore-forming geological background of the Truongson ore-forming belt in Laos, mineralization features and ore minerals of newly discovered porphyry Cu-Au deposits and skarn Fe ore deposits as well as their spatial relationships to the granite intrusions. On such a basis, an ore-forming model was tentatively established for the porphyry Cu-Au deposits, thus laying a foundation for building their ore-finding patterns and searching for the same ore deposits in this ore-forming belt. Based on both zircon U-Pb dating and the discrimination diagrams of Hf-Rb-Ta trace elements, it is inferred that these granites and related ore deposits might have been formed in an island arc setting developed by the subduction of the South China block beneath the Indochina block during Late Carboniferous.
Li W.-C.,China University of Geosciences |
Liu X.-L.,China University of Geosciences |
Zeng P.-S.,China Metallurgical Geology Bureau |
Yin G.-H.,Yunnan Geological Survey
Geology in China | Year: 2011
The Pulang porphyry copper deposit is a typical Indo-Chinese porphyry copper deposit in Zhongdian area, hosted in southern composite body of the Yidun structural-magmatic belt. The composite rock body is a hypabyssal -ultrahypabyssal intermediate -acid porphyry (porphyrite) body, which can be divided into three invasion stages, i.e., quartz diorite porphyrite, quartz monzonite porphyry, and granodiorite-porphyry. Geochemical characteristics show that the rocks are enriched with Ba, La, Rb, Sr, K, chalcophile elements Cu, Pb, and siderophile elements Mo, Ni, and are depleted in Nb, Zr, Hf and Ti. Porphyry (porphyrite) is the same as the rock series of granite island, belonging to cale-alkaline suite, and their genetic types are also similar to each other, belonging to I-type granite. The ore bodies are controlled by structures. The porphyry copper deposit mainly occurs in the Indo -Chinese intermediate -acid porphyry (porphyrite), and the mineralization was controlled by such factors as magmatic rocks, emplacement formation, uranium migration, hydrothermal alteration and structural space, which joindy constituted a porphyry metallogenic system characterized by the structural-magmatic- hydrothermal coupling in Indo-Chinese period.