FANG Wei-xuan1, Wang Lei1, LU Jia2, YU Zhi-yuan3
(1.China Nonferrous Metals Geology Survey, Beijing 100012, China;
2. Faculty of Land Resource Engineering, Kunming University of Science and Technology, Kunming 650093, China;3.Binnan Oil Production Plant, Shengli Oilfield Comlany, SINOPEC, Binzhou 256609，China)
Abstract: Chloritization is predominated in Sareka-type copper deposit. According to occurrences of chloritizations，they may be classified into A-, B-, C- and D-types of chloritization facies. Based on the study of mineral thermometer of chlorite and chlorite geochemical facies, it might have been that four different kinds of chloritization facies were one of the main factors for discolored alterationsin Sarekebayi Jurassic to Lower Cretaceous continental red-bed basin, and it was closely related to copper accumulations and mineralization for Sareke glutenite-type copper deposit. A-type and B-type chloritization facies may form with tectonic-thermal events, for A-type chloritization facies, exhibited among the mineral grains and intergrowth with chalcocite, exist along Jurassic and lower Cretaceous strata. The A-type may form at 163—217 ℃ with low heat flux at 40.39—48.43 Jm-2s-1, which cloud be produced by the tectonic-thermal event during the buried-compaction diagenesis stage. However, B-type chloritization facies with micro-veins, filled up along cross-layer fractures and micro-fractures, may be generated during the reworking-enrichment mineralization stage of the basin-fluid. The B-type intergrowth with chalcocite and bornite may be produced at 188—219 ℃ in higher thermal flux, i.e., 116.90—330.49 Jm-2s-1. It is assumed that bornite-chalcocite ore zone formed at 196—237 ℃ and bornite ore zone formed at 203—226℃, B-type with the highest heat flux at 330.49～878.78 Jm-2s-1, indicates the center part of reworking-enrichment mineralization of the basin-fluid in Sareke copper mine. B-type chloritization facies had multiple coupled with cataclastic lithofacies and bituminization alteration facies,whereas the higher the formation temperature is, the higher the permeability of fracture up to 30×10-6 cm2/211—227 ℃ will be, for the coupling relationship between the B-type chloritization facies and permeability of fracture. C-type and D-type chloritization facies may form with Paleogene tectonic-magamtic-thermal event, for C-type chloritization facies exhibiting block-spot and micro-vein existing in the margins of diabase-gabbro dykes and copper-bearing bleaching and discoloring altered zone. C-type chloritization facies in copper-bearing altered diabase dyke was produced at 175 ℃ and in the heat flux of 321.46 Jm-2s-1averagely, while C-type chloritization facies from discoloring glutenite of the Kezilesu Formation formed at the temperature ranging from 236 ℃ to 238 ℃ and in the heat flux ranging 442.86 to 922.63 Jm-2s-1. Finally, D-type chloritization facies disseminated in cataclastic altered diabase dyke, designated for the pale-thermal event of the diabase dyke, had altered and deformed. D-type chloritization facies may form at the temperature ranging from 121℃ to 185℃ with the average heat flux of 239.59 Jm-2s-1.
Keywords: chloritization facies；heat flux；tectonic-magamtic-thermal event；chlorite geochemical lithofacies; glutenite-type copper deposit
E-mail: fangweixuan@tom.com
ACTA MINERALOGICA SINICA Vol. 37, No. 5, 2017, Page 661
