From June 11 to 18, Professor Tony Naldrett of the University of Toronto, a Fellow of the Royal Society of Canada and the world's leading scientific expert on magmatic sulfide deposits, made a field trip to investigate the Emeishan large igneous province, in the company of research fellow TAO Yan and graduate students of the State Key Laboratory of Ore Deposit Geochemistry (SKLODG) in Institute of Geochemistry, Chinese Academy of Sciences (IGCAS).  Professor Naldrett has served as President of the Society of Economic Geologists, President of the Geological Society of America, President of the International Mineralogical Association, Chairman of the Board of the International Geological Correlation Programme and many other important positions.  He is an authority on the geology and origin of nickel-copper-platinum group element deposits.  On the basis of petrological, mineralogical and geochemical studies of the Noril’sk and Voisey’s Bay Ni-Cu-PGE deposits,he and his group of coworkers haveset up and refined a hypothesis for the formation of magmatic sulfide deposits in magma conduits.  This hypothesis is regarded as the most significant recent advance in understanding these deposits.

 

Prof. Tony Naldrett on the field trip to  the Emeishan large igneous province with Prof. TAO Yan and graduate students from IGCAS. (Image by IGCAS)

Professor Naldrett visited the V-Ti magnetite deposits in Panzhihua and basalts in Yanbian and Yanyuan county in this trip.  Taking a great interest in the high-grade V-Ti magnetite ores in Panzhihua area, Professor Naldrett expressed the view that these are the most outstanding examples of this type of mineralization in the world.  He enjoyed a detailed discussion on the mine geology with the geologists and a management officer of the Lanjian mine during his visit.  In addition, Professor Naldrett talked with the president of the Zhongchang Copper company concerning the geology of and exploration for the Qingkuangshan Ni-Cu-PGE deposit in Huili.

Professor Naldrett regards the Emeishan large igneous province as still having a high potential for mineral resources in the Xiaoguanhe area.  The different styles of ore deposits in the area suggest that multiple pulses of magma that have undergone variable degrees and types of crustal contamination have been involved. He expressed the opinion that both the magmatic sulfide and oxide deposits have formed in open-system conduits.  Further progress in the discovery of new deposits can be expected in the Xiaoguanhe area, where the Proterozoic basement to the ELIP outcrops in a dome.  During wide-ranging discussions, Professor Naldrett pointed out that though very careful geological surveys led to many discoveries in the 1970’s, recent new developments in exploration methodologies should be used to help future mineral exploration in the area.  He thinks it is worthwhile to set up a new plan to explore for mineral deposits in the region, including further systematic regional mapping and the use of helicopter-born magnetic, electromagnetic and possibly gravity surveys where the topography permits.  He suggests that further work should focus on regional structural mapping, especially that related to understanding magma plumbing systems, and geophysical surveys that will use the new improved methodologies that are now available to explore for deep concealed ore deposits.  In addition, he gives a high priority to continued basic studies to further elucidate the variety and uniqueness of the mineralization of Emeishan large igneous province, studies that will contribute to the development of ore-forming theory related with mantle derived magma.

The field trip will contribute to understanding in the study of magmatic ore deposits between the National Key Laboratory of Ore Deposit Geochemistry and the international world, and will also be helpful to broadening the study of the mineralization of the Emeishan large igneous province.

(By TAO Yan)