中国科学院机构知识库网格
Chinese Academy of Sciences Institutional Repositories Grid
Fluid-rock interaction modeling to constrain Au enrichment: Implication for the giant Jiaodong Au mineralization, eastern North China Craton

文献类型:期刊论文

AuthorHu, Huan-Long4; Fan, Hong-Rui1,3,5; Lan, Ting-Guang4,5; Yu, Xue-Feng2; Li, Da-Peng2; Yang, Kui-Feng1,5
SourceGONDWANA RESEARCH
Issued Date2024
Volume125Pages:91-109
KeywordFluid-rock interaction modeling Wallrock alteration Gold enrichment Metasomatized lithospheric mantle Jiaodong Peninsula
ISSN1342-937X
DOI10.1016/j.gr.2023.07.015
English AbstractThe devolatilization model of the metasomatized lithospheric mantle without pre-enriched gold has been proposed to account for the giant gold mineralization. An excellent example is the world-class Jiaodong gold province with >5000 tonnes Au resources in the eastern North China Craton. The auriferous fluid transport and gold enrichment during wallrock alterations are two vital processes to determine the giant gold mineralization formation in this province. However, the effects of the fluid-rock interaction with alterations on the auriferous fluid transport and gold enrichment still keep poor understanding, which leads the above model to be imperfect. The giant Jiaojia goldfield in this province recorded a wallrock alteration evolution from K-feldspar alteration to pyrite-sericite-quartz alteration, and some parts of the latter can become gold orebodies when the gold grade is >1 ppm. This study conducts thermody-namic fluid-rock interaction modeling to reveal auriferous fluid transport and coupled relationship between gold enrichment and alteration mineral assemblage based on the alteration-mineralization and ore fluid characteristics of the goldfield. The modeling of fluid-rock interaction with cooling indicates the transformation of Au-Cl complexes to Au-S complexes combined with the total sulfur concentration decrease by pyrite precipitation when cooling from-460 degrees C can trigger the dispersive gold precipitation, which should hinder the gold long-range transport to lower ambient temperature. The high oxygen fugacity at >400 degrees C can enhance Au-Cl complexes stability, and the low pH can maintain high total sulfur concentration in the auriferous fluid, both of which facilitate the long-range gold transport to a lower-temperature environment. The auriferous fluid would acquire higher pH by the buffering of feldspars or sericite, which was beneficial for the high-efficiency precipitations of pyrite and gold. The ankerite-siderite assemblage without pyrophyllite in the pyrite-sericite-quartz alteration zone indicates that a cumulative fluid to rock mass ratio (f/r) of 3.8-4.8 should be needed for the transformation from K-feldspar alteration to pyrite-sericite-quartz alteration according to the fluid-rock interaction modeling at 300 degrees C and 2000 bar. In the case of auriferous fluids with <= 200 ppb Au concentration, the single fluid-rock interaction can only elevate the gold grade to <= 0.69-0.87 ppm in the pyrite-sericite-quartz alteration zone at f/r 3.8-4.8. Therefore, the fracture-induced fluid flow coupled with fluid-rock interac-tion is proposed to the prerequisite to elevate the gold grade to >1 ppm in the pyrite-sericite-quartz alter-ation zone. The metasomatized lithospheric mantle volume for the required ore fluid and Au in the Jiaodong province is estimated according to the modeling results and alteration-mineralization charac-teristics, which provides a link between the mantle without abnormal Au enrichment and the alteration-mineralization processes.
WOS KeywordPARTIAL MOLAL PROPERTIES ; JIAOJIA GOLD DEPOSIT ; HIGH-PRESSURES ; HYDROTHERMAL ALTERATION ; TRANSPORT-PROPERTIES ; OROGENIC GOLD ; SANSHANDAO DEPOSIT ; MASS-TRANSFER ; PENINSULA ; TEMPERATURES
Funding ProjectNational Key Research and Development Program of China[2018YFA0702603] ; National Natural Science Foundation of China[41873048] ; West Light Foundation of The Chinese Academy of Sciences[xbzg- zdsys-202108]
WOS Research AreaGeology
Language英语
WOS IDWOS:001078991800001
PublisherELSEVIER
Funding OrganizationNational Key Research and Development Program of China ; National Key Research and Development Program of China ; National Key Research and Development Program of China ; National Key Research and Development Program of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; West Light Foundation of The Chinese Academy of Sciences ; West Light Foundation of The Chinese Academy of Sciences ; West Light Foundation of The Chinese Academy of Sciences ; West Light Foundation of The Chinese Academy of Sciences ; National Key Research and Development Program of China ; National Key Research and Development Program of China ; National Key Research and Development Program of China ; National Key Research and Development Program of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; West Light Foundation of The Chinese Academy of Sciences ; West Light Foundation of The Chinese Academy of Sciences ; West Light Foundation of The Chinese Academy of Sciences ; West Light Foundation of The Chinese Academy of Sciences ; National Key Research and Development Program of China ; National Key Research and Development Program of China ; National Key Research and Development Program of China ; National Key Research and Development Program of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; West Light Foundation of The Chinese Academy of Sciences ; West Light Foundation of The Chinese Academy of Sciences ; West Light Foundation of The Chinese Academy of Sciences ; West Light Foundation of The Chinese Academy of Sciences ; National Key Research and Development Program of China ; National Key Research and Development Program of China ; National Key Research and Development Program of China ; National Key Research and Development Program of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; West Light Foundation of The Chinese Academy of Sciences ; West Light Foundation of The Chinese Academy of Sciences ; West Light Foundation of The Chinese Academy of Sciences ; West Light Foundation of The Chinese Academy of Sciences