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1.
华北陆块北缘西段狼山—白云鄂博裂谷系中元古代形成的大型多金属矿床,是我国重要的铁、稀土、铜、铅、锌矿产地.矿床为产于沉积岩中热水沉积型多金属矿床.其形成受地层、构造控制,与裂谷作用有着密切的关系.裂谷系内外分支的地质环境及矿床矿种不同,导致矿床特征及成因具有一定差异.白云鄂博铁、稀土矿床为钾、钠、磷等含量较高的热水沉积型,霍各乞铜、铅、锌多金属矿床为与中基性火山岩有关的过渡热水沉积型,东升庙和甲生盘等铅、锌多金属矿床为热水沉积型.文中将对上述矿床分别进行论述. 相似文献
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华北陆块北缘西段中元古代与裂谷作用有关的铁、稀土、多金属矿床特征及成因 总被引：1，自引：0，他引：1
华北陆块北缘西段狼山—白云鄂博裂谷系中元古代形成的大型多金属矿床,是我国重要的铁、稀土、铜、铅、锌矿产地.矿床为产于沉积岩中热水沉积型多金属矿床.其形成受地层、构造控制,与裂谷作用有着密切的关系.裂谷系内外分支的地质环境及矿床矿种不同,导致矿床特征及成因具有一定差异.白云鄂博铁、稀土矿床为钾、钠、磷等含量较高的热水沉积型,霍各乞铜、铅、锌多金属矿床为与中基性火山岩有关的过渡热水沉积型,东升庙和甲生盘等铅、锌多金属矿床为热水沉积型.文中将对上述矿床分别进行论述. 相似文献
3.
对白云鄂博矿床大地构造环境的几点认识 总被引：1，自引：0，他引：1
分布于华北地台北缘的白云鄂博群厚万米，EW向展布长500km，宽20-50km，以碎屑岩为主，碳酸盐岩约占1/10。1997年，我们首次确定厚千余米的含矿岩系为海相火山沉积稀有金属碳酸岩—粗面岩；1982的，李继亮确定厚320m的次闪绿帘石岩（H15）为裂陷槽中的细碧角斑岩系。从而奠定了白云鄂博群属象谷沉积的基础。世界上许多富含轻稀土和铌和碱性岩、碳酸岩多产于裂谷系中。白云鄂博矿床中的特殊元素组合和稳定同位素组成只有裂谷带下的异常地幔才能提供。大量Sm-Nd同位素年龄资料说明白云鄂博矿床稀土成矿时代主要是中元古代，更证明了矿床成矿作用与裂谷发展的同步性。 相似文献
4.
白云鄂博群和渣尔泰山群是华北板块北缘中新元古代裂陷谷沉积的陆缘碎屑岩、泥页岩、碳酸盐岩及少量火山岩建造,赋存的典型金矿床有白云鄂博北部金矿床、朱拉扎嘎、浩尧尔忽洞等成型金矿床.从区域成矿角度看,由西向东构成了一个巨大的Au-Cu-Pb-Zn-S(Fe)-Mn-Au-REE-Nb-Fe热水沉积成矿系统.地质特征表明金矿床均具有明显的层控型特点;元素地球化学特征显示金的来源主要与中元古代火山活动及沉积地层有关;同位素年龄暗示一期重要成矿时代与华力西晚期的岩浆-构造事件相耦合.认为金矿床成因可概括为热水喷流沉积-热液叠加改造复合型.显示具有较大的找矿潜力. 相似文献
5.
华北陆块北缘西段狼山—白云鄂博裂谷系中元古代形成的大型多金属矿床 ,是我国重要的铁、稀土、铜、铅、锌矿产地。矿床为产于沉积岩中热水沉积型多金属矿床。其形成受地层、构造控制 ,与裂谷作用有着密切的关系。裂谷系内外分支的地质环境及矿床矿种不同 ,导致矿床特征及成因具有一定差异。白云鄂博铁、稀土矿床为钾、钠、磷等含量较高的热水沉积型 ,霍各乞铜、铅、锌多金属矿床为与中基性火山岩有关的过渡热水沉积型 ,东升庙和甲生盘等铅、锌多金属矿床为热水沉积型。文中将对上述矿床分别进行论述。 相似文献
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基于对海相碳硅泥岩含铀建造形成构造环境、成矿规律的系统研究,笔者提出中国碳硅泥岩型铀矿床形成的4种成矿体系类型：陆缘裂谷成矿体系、陆缘裂陷深断裂带成矿体系、陆块边缘陆缘盆地体系及陆缘活动带断陷台沟成矿体系;指出中国碳硅泥岩型铀矿的大规模成矿作用受控于陆缘裂谷和陆缘裂陷成矿环境下形成、伴随海底喷流作用和海底火山喷发而沉积的海相碳硅泥岩富铀建造。依据大型矿集区铀资源评价预测特征参数群,文章通过建立重点矿集区碳硅泥岩型铀矿资源矿集带预测评价判据和成矿预测体系,对中国碳硅泥岩型铀矿资源潜力进行总体评价。 相似文献
7.
华北陆块北缘西段中元古代与裂谷作用有关的铁、稀土、多金属矿床特征及成因 总被引：3，自引：0，他引：3
曹秀兰 《前寒武纪研究进展》2002,25(3):246-255
华北陆块北缘西段狼山－白云鄂博裂谷系中元古代形成的大型多金属矿床，是我国重要的铁、稀土、铜、铅、锌矿产地。矿床为产于沉积岩中热水沉积型多金属矿床。其形成受地层、构造控制，与裂谷作用有着密切的关系。裂谷系内外分支的地质环境及矿床矿种不同，导致矿床特征及成因具有一定差异。白云鄂博铁、稀土矿床为钾、钠、磷等含量较高的热水沉积型，霍各乞铜、铅、锌多金属矿床为与中基性火山岩有关的过渡热水沉积型，东升庙和甲生盘等铅、锌多金属矿床为热水沉积型。文中将对上述矿床分别进行论述。 相似文献
8.
中国碳硅泥岩型铀矿床时空演化规律 总被引：3，自引：0，他引：3
中国海相碳硅泥岩建造空间分布上受控于陆缘裂谷体系、陆缘裂陷体系、陆缘盆地体系及陆缘活动带断陷台沟体系,而大规模铀成矿作用与陆缘裂谷、陆缘裂陷环境下由海底喷流作用和海底火山喷发而沉积形成的热水沉积硅质岩、硅质磷块岩和碳硅质泥岩组成的含铀海相碳硅泥岩建造密切相关。铀矿床的空间分布受热液叠加改造驱动力条件制约,受红盆边缘断裂沟通效应影响。铀矿体的空间定位受切穿碳硅泥岩含铀建造的深大断裂及其派生的次级断裂、层间破碎带和联合断裂型复合带的控制。铀成矿时代则与形成热液叠加改造驱动力源的构造岩浆活化期相一致。 相似文献
9.
东帕米尔"层控碳酸岩型"铁铜金矿浅释 总被引：1，自引：0，他引：1
东帕米尔“层控碳酸岩型”铁铜金矿,形成于中元古代裂谷构造环境,产于中深变质相与中浅变质相转换部位,塔昔达坂群底部.矿床属海底喷流(含火山喷流)沉积成因,为菱铁矿和细碎屑岩-碳酸盐岩夹少量火山岩的沉积建造.铁铜金矿显示出上铁锰下铜金的元素垂向分带,构成新疆一个有希望的成矿区域. 相似文献
10.
内蒙古白音敖包地区金矿成矿特征及成矿系统演化 总被引：1，自引：0，他引：1
白云鄂博北部的白音敖包地区大地构造位置跨属华北板块北缘和中亚造山带,是一个多性质动力系统转换地带。高背景Au、Ag、Cu元素地球化学异常集中分布,发现了赛乌素、比鲁特、哈沙图、西皮、阿拉格敖包等多个成型金矿床,显示为一金矿矿集区。元素地球化学特征显示金可能来自地幔深源并与沉积地层有关;热液成矿温度在140~300℃之间;矿化类型具有多样性,成矿流体具有多源性,成矿时代具有多期性;矿床成因为热水喷流沉积-热液叠加改造复合型。矿集区经历了中元古代被动陆缘裂谷-热水沉积金成矿系统、早古生代活动陆缘的俯冲-沉积/造山金成矿系统、晚二叠世-三叠纪活动陆缘的碰撞-造山金成矿系统、燕山期构造体制转换-热液叠加金成矿系统、新生代表生变化金成矿系统等5个次级分支系统的顺序演化和叠加。 相似文献
内蒙古白云鄂博稀土-铌-铁矿床是世界上著名的巨型多金属矿床,但对其区域地质演化历史的认识至今仍不统一,而同位素年龄是解决矿床区域地质演化历史的有效手段。本文基于测年方法对白云鄂博矿床同位素年龄数据收集整理,结合矿床地质背景对矿床区域地质演化历史进行讨论:白云鄂博矿床发育在上太古界-下元古界结晶基底色尔腾山群之上,中元古代白云鄂博裂谷期的海底火山喷发-同生沉积作用发育了层状的含稀土铌铁矿层,同时发育了广泛的碳酸岩墙群和基性岩墙群,这是白云鄂博矿床最主要的成矿事件。白云鄂博矿床还经历过至少三次后期成矿热事件叠加或改造成矿,主要包括:(1)新元古代南华期热事件(约720Ma);(2)早古生代志留纪晚期叠加成矿事件(约440Ma);(3)晚古生代二叠纪岩浆岩侵入事件(约280Ma)。白云鄂博矿床是中元古代裂谷成矿事件为主并叠加了后期多次热事件的结果。 相似文献
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白云鄂博铁、铌、稀土矿床:研究进展、存在问题和新认识 总被引：2，自引：1，他引：1
白云鄂博是世界第一大稀土元素矿床,其稀土元素资源量占世界目前已知稀土元素资源总量的三分之二以上,具有重要的经济和战略地位。白云鄂博自1927年发现至今已有92年,对其的开发和研究历史悠久,在赋矿碳酸岩的成因、成矿年代、稀土矿物学等方面取得了一系列重要进展,为碳酸岩型稀土元素成矿理论发展做出了突出贡献。由于矿床经历了成矿后复杂的构造变形和热液蚀变,致使其地质、地球化学特征复杂,学界对其成因和成矿过程一直存在不同认识,对成矿碳酸岩的岩浆演化、稀土元素迁移与富集机理等方面的研究也相对薄弱。笔者最新研究表明,矿区过去被认为是下白云鄂博群的H1、H2、H9岩石单元并非沉积变质岩或变质火山岩,而应为岩浆侵入成因,矿区其他岩石单元(H3～H7)的成因也值得商榷。H9岩石单元中的黑云母岩(前人称为黑云母板岩)和富含黑云母的碳酸岩(前人称为暗色板岩)为成矿碳酸岩的一部分,是碳酸岩不同岩相带的表现。黑云母岩和富黑云母碳酸岩相对于含矿碳酸岩具有相对低的稀土元素含量和轻、重稀土元素比值,表明岩浆演化可能对稀土元素的富集和分异具有重要贡献。矿区主要岩石单元成因的新认识不仅为矿床成因、成矿背景研究提供了新的依据,同时也为研究区域构造演化、正确厘定矿区构造式样和指导矿区深部和外围找矿提供了新的思路。 相似文献
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Geochemical constraints on the genesis of the Bayan Obo Fe-Nb-REE deposit in Inner Mongolia, China 总被引：2，自引：0，他引：2
Trace element and isotopic compositions of carbonate from ore bodies, country rock which hosts the ore bodies (H8 dolomite), a carbonatite dyke exposed in Dulahala near Bayan Obo, and rare earth element (REE)-rich dolomite in Bayan Obo have been determined to understand the genesis of the Bayan Obo Fe-Nb-REE ore deposit, the world’s largest resource of REE. The REE and trace element distribution patterns of samples from the REE-rich carbonatite dykes are identical to those of mineralized carbonate rocks, indicating a genetic linkage between the REE-rich carbonatite and mineralization in this region. By contrast, carbon and oxygen isotopes in the mineralized carbonate varied significantly, δ13C = −7.98‰ to −1.12‰, δ18O = 8.60-25.69‰, which are distinctively different from those in mantle-derived carbonatite. Abnormal isotopic fractionations between dolomite and calcite suggest that these two minerals are in disequilibrium in the carbonatite dyke, ore bodies, and H8 marble from Bayan Obo. This isotopic characteristic is also found in mineralized sedimentary marine micrite from Heinaobao, ∼25 km southeast of the Bayan Obo Fe-Nb-REE ore deposit. These facts imply that the carbonate minerals in the Bayan Obo deposit have resulted from sedimentary carbonate rocks being metasomatised by mantle-derived fluids, likely derived from a REE-enriched carbonatitic magma. The initial Nd isotope values of ore bodies and carbonatite dykes are identical, indicating that ore bodies, carbonatite dykes and veins may have a similar REE source. 相似文献
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内蒙古白云鄂博REE-Fe-Nb矿床是世界罕见的超大型多金属矿床, 但矿床成因一直没有解决, 而年代学研究是解决矿床成因的基础。本文结合矿床地质特征, 系统地分析了前人的年代学研究成果, 并对白云鄂博矿床的Sm-Nd同位素体系进行了深入的分析和讨论。结果表明, 白云鄂博稀土的成矿时代约为1.3 Ga, 与碳酸岩墙的形成时间一致, 成矿物质来源于地幔。加里东期的热事件(约0.44 Ga)导致了白云鄂博矿床晚期稀土矿脉的形成和原有矿体中部分稀土矿物的重结晶, 但成矿物质主要来源于矿体内部的稀土再循环, 外源物质的贡献不明显。约1.3 Ga到约0.44 Ga间的一系列中间年龄为后期热扰动的结果, 并不代表成矿事件。简言之, 白云鄂博矿床只在中元古代发生过一次实质性的稀土矿化作用, 地幔是稀土物质的单一源区。 相似文献
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Yongbei Zhang Shihua Sun Chengyan Xu Hao Wang Chongsun Zhao Zhihua Zhu 《Resource Geology》2003,53(4):261-272
Abstract. The Kunyang rift on western margin of Yangtze Platform is a continental rift, and also a rare Precambrian Fe-Cu mineralization zone in China. The Wuding-Lufeng mineralization area in the middle section of the rift is an important part of the zone, and an elliptic-shaped volcanic collapsed basin, controlled by a ring fracture system with carbonatitic volcanic rocks mainly occurring along the northwestern edge of the basin. The Hetaoqing Fe-Cu ore deposit at the western side of the basin is hosted in carbonatitic volcanic rocks and pyroclastic sedimentary rocks. The original ore bodies occur as layers, bands and lenses conformable to the host carbonatitic rocks. The ores usually appear as massive, impregnated and granular in carbonatitic rocks, and as brecciform and sandy in pyroclastic sedimentary rocks. Ore-forming minerals are magnetite, hematite, chalcopy-rite, bornite, pyrite, carrollite, molybdenite, cobaltite and skinnerite, and secondary minerals limonite, chalcocite, azurite, malachite and tenorite. Gangue minerals are calcite, dolomite, ankerite, common hornblende, arfvedsonite, augite, aegirine-augite, albite, phlogopite, biotite, chlorite and apatite. Evidences of mineral chemistry, trace elements and isotopic ratios of ores, as well as geological features, suggest that the original ores are igneous in origin. Chemical features of magnetites in the deposit belong to carbonatite type, and are similar to those from the Bayan Obo carbonatites. The ores are rich in iron, titanium, rare earth elements, niobium, tantalum, gold, silver, phosphor and sulfur. These features indicate that the Fe-Cu deposit associated with volcanic activity in the Wuding-Lufeng basin is alkali-carbonatite volcanic type. 相似文献
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《International Geology Review》2012,54(14):1720-1731
The origin of the Bayan Obo ore deposit, the largest REE deposit in the world, has long been debated and various hypotheses have been proposed. Among them is that the Bayan Obo ore deposit is correlated with and has the same origin as the Sailinhudong micrite mound in the southern limb of the Bayan Obo synclinorium. To test this model, the Bayan Obo ore deposit and the Sailinhudong micrite mound are systematically compared for their geological features, elemental geochemistry, and C, O, and Mg isotopic geochemistry. We show that the Bayan Obo ore deposit and the Sailinhudong micrite mound are both calcareous, lens-like in shape, lack bedding features, and are both hosted in a sedimentary formation that consists of clastic sediments and carbonates, unconformably overlying the Archaean–Palaeoproterozoic crystalline basement. However, their geochemical characteristics differ markedly. Compared with the Sailinhudong micrite carbonates, the Bayan Obo ore-hosting dolomite marbles are strongly enriched in LREEs, Ba, Th, Nb, Pb, and Sr, and have very different (PAAS)-normalized REE patterns. Sailinhudong micrite carbonates have higher δ13CPDB and δ18OSMOW values, falling into the typical sedimentary field, but the Bayan Obo ore-hosting dolomites are isotopically intermediate between primary igneous carbonatite and typical sedimentary limestone. The δ26 Mg values of the Sailinhudong micrite carbonates are lighter than those of normal Mesoproterozoic sedimentary dolostone, while those of the Bayan Obo ore-hosting dolomite marble are isotopically heavier, similar to δ26 Mg of mantle xenoliths and Bayan Obo intrusive carbonatite. We conclude that the Bayan Obo ore deposit is not correlated with the Sailinhudong micrite mound; it is neither a micrite mound nor an altered micrite mound. 相似文献
18.
近年来关于白云鄂博Nb-REE-Fe矿床H8岩体火成水成归属的争论已渐息,而矿床成矿过程以及REE富集机制仍是学术界关注的热点。文章对白云鄂博矿床白云石碳酸岩体、霓长岩化蚀变带、尖山组板岩3个典型剖面开展系统的岩石地球化学工作,发现赋矿碳酸岩、霓长岩、铁矿石微量与稀土元素配分模式具有相似性,靠近H8岩体的尖山组板岩往往有着更高的稀土元素含量,以及与成矿碳酸岩相近的微量元素配分模式。区内各类岩石单元稀土元素分馏明显,全岩LaN/NdN比值的变化规律显示,H8岩体内部比边缘更富La,边缘比岩体内部更富Nd。通过岩（矿）石薄片BSE图像结合矿物电子探针分析显示,H8岩体内的稀土元素矿物（主要是独居石、氟碳铈矿等）可分为2组,一组相对富La,呈半自形-他形,星点状分布;另一组相对富Nd,呈他形细粒,脉状分布。两组矿物中不同元素的富集特征可能代表了结晶过程中流体环境的改变。上述实验结合地质勘查结果表明,白云鄂博矿床初始成矿物质的起源与H8碳酸岩一致,均来源于中元古代碳酸岩岩浆活动,而不同类型的稀土元素矿物对应了白云岩成岩阶段与萤石矿化阶段两个不同的稀土矿化阶段。 相似文献
19.
金豆子山铅锌矿赋存于华北地台北缘、白云鄂博裂谷带中的中元古界白云鄂博群地层中,属中低温热液矿床,受断裂破碎带控制。该矿床地表已控制的Ⅰ号矿带为矿床的主矿带,Ⅱ、Ⅲ、Ⅳ号矿带为隐伏矿带。矿石储量670多万吨,铅锌金属量约24万吨,平均品位铅1.85%,锌1.65%。围岩蚀变有褐铁矿化、硅化、绢云母化、绿泥石化、含铁锰碳酸盐化等。今后找矿的方向为金豆子山倒转背斜的断裂破碎带内,进一步勘查有望找到成因类似的铅锌矿床。 相似文献
20.
《地学前缘(英文版)》2016,7(3)
Bayan Obo ore deposit is the largest rare-earth element(REE) resource,and the second largest niobium(Nb) resource in the world.Due to the complicated element/mineral compositions and involving several geological events,the REE enrichment mechanism and genesis of this giant deposit still remains intense debated.The deposit is hosted in the massive dolomite,and nearly one hundred carbonatite dykes occur in the vicinity of the deposit.The carbonatite dykes can be divided into three types from early to late:dolomite,co-existing dolomite-calcite and calcite type,corresponding to different evolutionary stages of carbonatite magmatism based on the REE and trace element data.The latter always has higher REE content.The origin of the ore-hosting dolomite at Bayan Obo has been addressed in various models,ranging from a normal sedimentary carbonate rocks to volcano-sedimentary sequence,and a large carbonatitic intrusion.More geochemical evidences show that the coarse-grained dolomite represents a Mesoproterozoic carbonatite pluton and the fine-grained dolomite resulted from the extensive REE mineralization and modification of the coarse-grained variety.The ore bodies,distributed along an E-W striking belt,occur as large lenses and underwent more intense fluoritization and fenitization.The first episode mineralization is characterized by disseminated mineralization in the dolomite.The second or main-episode is banded and/or massive mineralization,cut by the third episode consisting of aegirinerich veins.Various dating methods gave different mineralization ages at Bayan Obo,resulting in long and hot debates.Compilation of available data suggests that the mineralization is rather variable with two peaks at~1400 and 440 Ma.The early mineralization peak closes in time to the intrusion of the carbonatite dykes.A significant thermal event at ca.440 Ma resulted in the formation of late-stage veins with coarse crystals of REE minerals.Fluids involving in the REE-Nb-Fe mineralization at Bayan Obo might be REE-F-C02-NaCI-H20 system.The presence of REE-carbonates as an abundant solid in the ores shows that the original ore-forming fluids are very rich in REE,and therefore,have the potential to produce economic REE ores at Bayan Obo.the Bayan Obo deposit is a product of mantle-derived carbonatitic magmatism at ca.1400 Ma,which was likely related to the breakup of Columbia.Some remobilization of REE occurred due to subduction of the Palaeo-Asian oceanic plate during the Silurian,forming weak vein-like mineralization. 相似文献