【作者】 龚瑞君；

【导师】 倪师军；

【作者基本信息】 成都理工大学 ， 地球化学， 2010， 硕士

【摘要】 华北地台北缘中西段是我国前寒武纪地层出露较齐全的地区之一,已经发现本区前寒武纪地层中有许多重要的矿产资源产出,如铜铅锌、金及稀土元素等多金属矿产资源。基于中国核工业地质局的科研项目《华北地台北缘中西段前寒武纪铀矿成矿条件及找矿方向》,作者通过对产于华北地台北缘中西段前寒武纪地层中的特大型大型矿床的地质特征的分析及同位素资料,认为其存在四次重大成矿地质事件,分别为新太古代成矿地质事件(〉2500Ma)、古元古代成矿地质事件(2500～1800Ma)、中元古代成矿地质事件(1800～1000Ma)及古生代～中生代成矿地质事件(543～65Ma)。(1)新太古代成矿地质事件主要表现为2700Ma基性火山作用、2500Ma中酸性岩浆作用及广泛而强烈发育的变质作用;此期主要形成太古宙花岗岩—绿岩带中的金矿床,条带状铁矿床,还有中高变质岩中的石墨矿床。(2)古元古代成矿地质事件主要是发生在2350～2100Ma和2100～1800Ga期间的造山事件,期间伴随着大量的中酸性花岗岩浆活动,对新太古代花岗绿岩带进行叠加改造,带入金质物质,形成了排山楼金矿床;古元古代也是重要的铅锌成矿期,区内蔡家营铅锌矿床的形成与该期的构造热事件密切相关。(3)中元古代成矿地质事件是研究区最为重要的成矿事件,主要表现为中元古代早期(1800Ma～1300Ma)华北古大陆的裂解事件和中元古代晚期(1300Ma～1000Ma)的汇聚事件,并形成了狼山—渣尔泰山裂陷槽和白云鄂博裂陷槽两大裂陷槽。中元古代产生了一批特大型大型矿床,如白云鄂博稀土铁铌矿床、狼山—渣尔泰山硫多金属成矿带、高板河铅锌—黄铁矿矿床、大庙钒铁矿床、及锰矿床等。(4)古生代～中生代成矿地质事件主要是在之前形成构造基底上进行改造,裂解拼合,同时伴随着强烈的岩浆侵入活动并伴随着成矿物质的侵入,尤其是海西期和燕山期的岩浆活动异常频繁。形成了东坪金矿床,峪耳崖金矿床等。研究区前寒武纪地层中的金矿、铜铅锌矿、锰矿、铁矿、稀土矿等矿床都受区域性大断裂和岩浆岩带控制。除兴和石墨矿只受前寒武纪的区域变质作用影响。矿床成矿作用具有多期性,叠加性,尤其是金矿床。更多还原

【Abstract】 Based on a research project <Metallogenic condition and prospecting of uranium deposit in Precambrian in west and central part of north margin, north china platform>from China Nuclear Industry Geological Bureau, the author described the geological features of the large-scale deposits which occur in the precambrian strata in the central and western part of North Margin in north china platform, and divided four major metallogenic events, they are Neo- archean metallogenic geological events, Paleoproterozoic metallogenic geological events (2500 ~ 1800Ma), Mesoproterozoic metallogenic geological events (1800 ~ 1000Ma) and Paleozoic ~ Mesozoic metallogenic geological events (543~65Ma).(1) Neoarchean metallogenic geological events are mainly for the 2700Ma basic volcanism, 2500Ma acidic magmatism and strong and widely development of metamorphism; this stage mainly formed gold deposits in Archean granite-greenstone belt, banded iron deposits, and the graphite deposits which occur in high-grade metamorphic rocks.(2) Paleoproterozoic metallogenic geological events mainly took place in 2350~2100Ma and 2100~1800Ga orogenic events during the period, with a large number of magmatic activity, the NeoArchean granite-greenstone belt was modificated and superposed, which was bringing gold into the granite-greenstone belt, and gold deposits formed such as the Paishanlou gold deposit; Proterozoic is an important period of forming lead-zinc mineralization, in the region Caijiaying business lead-zinc deposit formation and the period is closely related to tectonic events.(3) Mesoproterozoic metallogenic geological events is the most important metallogenic event in the study area, mainly for the north of ancient continent of cracking events in the early Mesoproterozoic (1800Ma~1300Ma) and the splitting event in the late Mesoproterozoic (1300Ma~1000Ma), and formed two big taphrogenic trough of Langshan-Zha’ertaishan rapture and Bayan Obo rapture. This time produced a large number of deposits, such as the Bayan Obo Nb-Fe deposit, Wolf Mountain-Zha’ertaishan Sulphur polymetallic ore belt, Gao banhe lead and zinc-pyrite deposit, Temple of vanadium and iron deposits and manganese ore bed and so on.(4) Paleozoic ~ Mesozoic metallogenic geological events is mainly formed in the previous structure to transform the substrate, cracking and put together, accompanied by strong magmatic intrusion into the activities and accompanied by the intrusion of minerals, particularly the stage of Yanshanian and Hercynian, the magmatic acted very abnormal and frequently. This period formed Dongping gold deposit, yu’erya gold deposits and so on.The mining area of gold, copper and lead-zinc, manganese, iron ore, rare-earth ore in the Precambrian strata of study area are mainly controlled by deep faults and magmatic rocks. Xinghe graphite mine only closely related with the regional metamorphism of the Precambrian, its formation mainly impacted by sedimentary environmental. Deposits in the region are multi-phase nature, cascade, especially the gold deposit.更多还原