| 滇东北会泽超大型铅锌矿床矿质来源与改造成矿作用 |
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| 引用本文： | 冉崇英.滇东北会泽超大型铅锌矿床矿质来源与改造成矿作用[J].高校地质学报,2017,23(4):563. |
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| 作者姓名： | 冉崇英 |
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| 摘 要： | "改造成矿作用"理论是中国科学院涂光炽院士提出的完善矿床成因分类学"四分法"的新理论,是中国学者对世界地球科学的重要贡献。该文根据会泽铅-锌(银、锗)矿床地质地球化学特征,列举其沉积改造的充分证据,用改造成矿的四大要素审视其矿床成因,认同它是典型而独特的沉积—强烈改造矿床,并以重要的宏观地质为依据,注意到峨眉山玄武岩(260 Ma)本身及昆阳群褶皱基底均未赋存一定规模的铅锌矿床,认为玄武岩与基底供给会泽铅锌矿(245~246 Ma)成矿物质有限,成岩与成矿时差太大,且成矿断层切割玄武岩,说明玄武岩成岩在先,铅、锌成矿在后,二者无直接成因联系。对会泽铅锌矿床的物质来源,有主张来自地层、基底、玄武岩或多来源者,但以何者为主,多种金属是否同源尚缺深入讨论,文章特别对地层、基底、峨眉山玄武岩中各成矿元素的含量、富集系数及富集类型进行系统的求算与分析研究,以讨论各种成矿金属的可能来源几率及其对成矿的贡献估计。结果显示:银在各地质体中均高倍富集,可提供充沛矿质,铅次之;锌则相反,多为正常元素或亏损元素,锗、镓、铟亦然,故矿石中的锌、锗、镓、铟,更可能为深部提供。结合大量的微量元素、稀土元素、铅、硫、锶、碳、氢、氧同位素等地球化学资料分析研究,认为地层,特别是震旦—寒武系、泥盆系、下石炭统摆佐组(C1b)与深部是主要的矿质来源,不同金属可同源或异源。矿床受地层岩性与构造的双重控制,与岩浆活动无关,具备改造成矿要素,属典型的沉积—强烈改造铅锌矿床,且具超大、特富、多金属富集的独特性。海西期下石炭统摆佐组已沉积成岩成矿或形成矿源层,后经印支期构造运动强烈改造而超常富集成矿,多掩盖其沉积特征,它属于沉积改造矿床"会泽式"。
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| 关 键 词： | 改造成矿作用 会泽超大型铅锌矿床 峨眉山玄武岩 成矿物质来源 |
Ore-forming Material Sources and Sedimentary-reworked Metallization of Huize Super-large Lead-Zine Deposits in Northeastern Yunnan,China |
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| Abstract: | The theory of reworked metallization is a new theory to optimize the quartering method of genetic classification of mineral
deposits. It is proposed by Chinese scientist Prof. Tu Guangzhi, and is a great contribution to earth sciences in the world from Chinese
scholar. This article applies the theory of reworked metallization to examine the genesis of Huize super large Pb-Zn deposit. Based on
the geological and geochemical characteristics, we suggest that it is a typical and special sedimentary-strongly reworked deposit. On the
basis of macroscopic phenomena, there are no significant Pb-Zn deposits in the Emeishan Basalts （260 Ma） and Kunyang folded
basement. It is believed that basalts and basement cannot provide the ore-forming material sources. Meanwhile, the metallogenetic fault
cuts through the basalts, indicating that basalts formed prior to metallization and basaltic magma is not the mineralization factor. Theare various opinions on the ore genesis and ore-forming material sources, such as strata source, basement source, basalt source, and
multi-source. However, so far there is still no deep insight into the primary source of the ore-forming material, and it is controversial
whether multi-metals have unique source. In this paper, we systemically calculate and analyze the content, enrichment coefficient, and
enrichment type of ore-forming elements in the strata, basement, and Emeishan basalt to discuss the possible sources of all kinds of
ore-forming metals and estimate its contribution to the mineralization. Results show that Silver is high in geological units everywhere, Pb
comes second; while on the contrast, Zn, Ge, Ga, and In are normal or depleted elements. So the Zn, Ge, Ga, and In of the ore are more
likely come from the deep. Based on the geochemical data of trace and rare earth elements, Pb, S, Sr, C, H, O isotopes, we conclude that
the Z, , D, C strata and deep are the main ore-forming material sources and multi-metals may have same or different sources. The
deposit is controlled by stratigraphic lithology and tectonics, but has no direct relationship with magma. The deposit shows features of
reworked metallization and belongs to the strongly reworked sedimentary deposit which is characterized by very high grade of the ore,
more associated metals, and super-large size. The stratified ore-bodies or source bed formed in Hercynian, and abnormal enrichment
occurred during the later Indosinian movement. We called it“Huizetype”sedimentary-reworked deposit. |
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| Keywords: | reworked metallization Huize super large lead-zine deposits Emeishan basalts ore-forming material |
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