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萨亚克铜矿田是中亚成矿域巴尔喀什成矿带唯一的以矽卡岩型铜矿化为主的大型铜矿床,产在哈萨克斯坦的萨亚克复向斜内。铜矿田包括了几个在空间上相对独立的矽卡岩型铜矿床、斑岩型铜钼网状脉矿床和一系列石英脉型矿脉,构成了斑岩型和矽卡岩型两个端元形成的成矿系列,但以矽卡岩型为主。铜矿田花岗岩类岩石的锆石SHRIMPU-Pb定年,给出了两期与矽卡岩型铜成矿作用有关的深成岩浆作用的时代,早期的闪长岩结晶年龄为335±2Ma,晚期的花岗闪长岩结晶年龄为308±10Ma,反映了两期矽卡岩型铜成矿作用的年龄。结合成矿元素分析,认为早期335±2Ma为主要成矿期年龄,而308±10Ma为次要成矿期年龄。区域成矿时代的分析表明,主矽卡岩型成矿期先于区域的斑岩型铜成矿作用而发生,次要的矽卡岩型成矿期略晚于区域斑岩铜成矿期。花岗岩类岩石中的角闪石、黑云母、钾长石40Ar/39Ar测年结果进一步限定了矽卡岩型铜成矿作用的时代,分别给出冷却年龄为286.6±6.7Ma、306.6±2.9Ma和257±11Ma。4个花岗岩类岩石中的磷灰石裂变径迹测年和热历史模拟给出年龄范围为85.4±4.5Ma至66.9±4.1Ma,说明了矽卡岩型萨亚克铜矿田的剥露作用主要发生在晚白垩世晚期。本文花岗岩类岩石的U-Pb、40Ar/39Ar和裂变径迹热年代学研究,揭示了萨亚克铜矿田从深成的岩浆侵入活动、成矿作用、区域冷却到剥露作用的全过程。
The SAYAK copper field is the only large-scale copper deposit dominated by skarn-type copper mineralization in the Balkhash metallogenic belt in Central Asia, and is located within the Yaakov syncline in Kazakhstan. The copper field consists of several relatively skarn-free copper deposits, porphyry copper-molybdenum reticular vein deposits and a series of quartz veins, forming two porphyry and skarn types Endmember formed metallogenic series, but based skarn type. The zircon SHRIMPU-Pb dating of granitic rocks in the copper ore field gives two epochs of deep magmatic activity related to skarn-type copper mineralization. The early age of the diorite is 335 ± 2Ma, and the late The crystallization age of granodiorite is 308 ± 10Ma, which reflects the age of two skarn-type copper mineralization. Based on the analysis of ore-forming elements, it is considered that the early 335 ± 2Ma is the main metallogenic age and the 308 ± 10Ma is the secondary metallogenic age. The analysis of the regional metallogenic epoch shows that the main skarn type mineralization occurred earlier than the regional porphyry copper mineralization, and the secondary skarn mineralization slightly later than the regional porphyry copper mineralization . The 40Ar / 39Ar dating results of amphibole, biotite and potassium feldspar in granitic rocks further define the age of skarn copper mineralization, and the cooling ages are 286.6 ± 6.7Ma, 306.6 ± 2.9Ma And 257 ± 11Ma. Apatite fission track dating and thermal history simulations in four granitoids show ages from 85.4 ± 4.5Ma to 66.9 ± 4.1Ma, illustrating the exhumation of the skarn type Sakya copper field Mainly occurred in late Late Cretaceous. The U-Pb, 40Ar / 39Ar and fission track thermochronological studies of granitoids in this paper reveal the whole process of the magmatic intrusive activity, mineralization and regional cooling to detritalization of the Yajac copper orefield .