【作者】 王长明；

【导师】 邓军； Qiuming Cheng；

【作者基本信息】 中国地质大学（北京） ， 矿物学、岩石学、矿床学， 2008， 博士

【摘要】 中国大兴安岭中南段位于东西向古生代古亚洲构造-成矿域与北北东向中新生代滨西太平洋构造成矿域强烈叠加复合-转换的部位。从而使大兴安岭地区的成矿地质条件优越、成矿期次多、成矿强度大、矿床类型多样。大兴安岭中南段铜多金属矿床的前期研究工作多注重花岗岩成矿理论及模式的建立,认为区内矿床大都是与燕山期岩浆活动有关的热液矿床。笔者经过近五年的野外和室内工作,通过区城地质、地层地球化学、岩石学、岩石化学、微量元素,同位素和流体包裹体等方面综合研究了区内古生代喷流-沉积成矿作用特征,结合成矿理论和数学地质理论进行成矿预测,取得如下一些新的认识:(1)首次对大兴安岭中南段在二叠纪沉积盆地演化过程中的水下喷流-沉积成矿作用特征进行深入系统的研究,从而厘定了一个新的成矿时代和成矿系列,尽管历来被人们所忽视,但其重要性可能并不亚于燕山期的岩浆热液成矿作用。(2)热水沉积岩和热水沉积成矿作用是当前地学界前缘的研究热点之一,主要集中在深海盆地中,但是对于很浅的海水/湖水的浅水环境研究较少,国内也仅仅对湖相成因的喷流岩做过一些分析研究。作者首次对浅水环境下形成的喷流-沉积矿床进行系统分析,这对矿床学的研究无疑是认识上的新突破。(3)首次将喷流-沉积成矿划分为如下2种类型:海底喷流-沉积成矿和湖相喷流-沉积成矿。研究区海底喷流-沉积成矿以小坝梁VMS型铜、金矿床和黄岗梁层控夕卡岩型锡、铁多金属矿床为代表;湖相喷流-沉积成矿以大井SEDEX型锡、铜多金属矿床为代表。(4)首次将研究区喷流-沉积成矿的环境厘定为裂陷槽盆地,并对其做了深入翔实的分析。(5)以成矿理论和数学地质理论为指导,研究地质、物探、化探和遥感信息之间的关联,并首次运用证据权重法(Weights of Evidence Model)建立该区的证据权重成矿预测模型,圈定喷流-沉积成矿的找矿远景区。这一研究对该区的矿产资源预测与评价具有重要的参考价值。更多还原

【Abstract】 The middle-southern segment of the Da Hinggan Mountains is located at the supperimposed, composite and transformed portion where the Mesozoic NNE-stretching tectonic domain of the global Circum-Pacific belt strongly overprints the Paleozoic E-W-stretching tectonic domain of the Paleo-Asian Ocean. The early-stage research of copper-polymetallic deposits has been largely focused on magmatic metallogenic theory and model. Based on this fact, most of the ore deposits were regarded as epigenetic hydrothermal deposits in genetic connection with the Mesozoic magmatism. Based on the previous studies, this work is mainly aimed at the genesis and evolution of subaqueous exhalative mineralization by the study on the regional geology, strata geochemistry, petrology, mineralogy, petrochemistry, trace elements, isotopes and fluid inclusion, and some scientific results are obtained as follows:(1) It is a new opinion that the subaqueous exhalative mineralization has occured during the basin evolution at the Permian time in the study area, which is ignored and poorly understood, but might be as important as the hydrothermal mineralization connected with the Mesozoic magmatism.(2) Exhalites and the exhalative sedimentary mineralization has been the research hotspot in recent years among the geologists, which were largely focused on deep-sea basin, but scarcely on the shallow subaqueous environment. Especially in China, this research is limited to shallow subaqueous exhalites, but scarcely to mineral deposits. A new type shallow water exhalative mineralization is put forward to in this paper for the fist time. What’s more, it is an innovative breakthrough to mineral deposits.(3) In the study area, the exhalative sedimentary deposits are divided into the Xiaobaliang VMS type deposit related to the deep-sea basin environment, and the Dajing SEDEX type deposit related to the lacustrine basin environment for the first time.(4) The geological setting of subaqueous exhalative mineralization was regarded as“Dashizhai Rift Basin”(DRB) for the first time, between the“Siberia Plate”(SP) and the“North China Plate”(NCP).(5) Guided by the mineralization theory and the theory of mathematieal geology, from the perspective of geological evolution, we studied the relationship of geology, physical exploration and geochemical exploration. The GIS-based weights of evidence modeling has been constructed, and forecast prospects have been delineated by using GIS techniques on the basis of the geological data. The results of research will provide a scientific basis for the further exploration and development of the mineral resources in the study area.更多还原