鄂西地区牛蹄塘组钼钒矿地质特征及找矿远景探讨     

陈家林  田文  牟宗玉  聂开红 《华南地质与矿产》2010,(1):40-47

寒武系下统牛蹄塘组黑色岩系广泛分布于鄂西地区,层内现已发现众多的钼钒矿床(点),其形成条件具有热水沉积与正常海相沉积双重特征,成矿系统总体上处在海侵体系域陆棚盆地还原沉积环境,期间由区域性断裂构造的热水喷流提供多种金属元素来源,经炭质、粘土矿物吸附作用沉积成矿,其中Ni、Mo与喷流作用最为密切,钒与生物化学作用密切,具有较好的找矿远景。  相似文献   

内蒙古大青山地区碎屑岩型金矿控矿系统及其找矿意义          下载免费PDF全文

杨亮  王继革  田优杰 《地质找矿论丛》2010,25(3):206-211

大青山地区碎屑岩型金矿控矿系统表现为:古元古代大陆裂陷槽构造环境为金矿成矿提供背景条件(物质场、能量场、空间场),该环境下沉积的二道凹群中部的红山沟组下部复理石建造为金矿成矿提供物质条件,该建造在造山早期由拉伸机制形成的顺层滑脱剪切带控制成矿带,剪切带内的同期次级褶皱构造(尤其是向斜、向形构造)为金矿成矿提供容矿空间;提出了层位(复理石建造)、顺层滑脱剪切带及相关次级褶皱构造三者叠加控矿的金矿控矿型式。  相似文献   

广西乐业林旺金矿床构造解析及构造成矿作用   总被引：4，自引：1，他引：3  

陈懋弘  黄庆文  李继贤  蒋柏昌  张长明 《大地构造与成矿学》2010,34(3)

详细的构造解析表明,矿床构造线主要分为南北向、北东东向和北西向三组,其中造山期间形成的南北向构造线(不对称褶皱和逆冲断层)控制了矿床的基本构造格架。后碰撞造山侧向挤压期间构造应力场发生近直交的改变,一方面使造山期形成的褶皱发生重褶,形成走向北东东的叠加褶皱;另一方面导致F1的左旋-正滑运动,矿液沿着断层拉张的空间沉淀就位。矿床构造演化至少经历了同生期裂陷、造山期挤压和后碰撞造山侧向挤压等三个阶段,成矿发生在后碰撞造山侧向挤压阶段。层状矿体主要赋存于背斜构造中,在空间上与赋存于断层中的脉状矿体相连。能干性和渗透性明显不同的地层组合是形成层状矿体的岩性基础,断裂构造则是主要控制因素。泥质不透水层分别与反冲断层、背斜构造组成的构造圈闭,以及两期非共轴背斜叠加形成的构造高点则是形成厚大矿体的主要原因。林旺金矿在烂泥沟金矿与水银洞金矿之间形成了一个从脉状型式→脉状和层状之复合型式→层状型式的完整矿床型式系列。这种复合矿床型式直观地表明了层状矿体是后生热液成因矿床。  相似文献   

东辛油田沙三中亚段沉积特征与油藏分布规律          下载免费PDF全文

陈秀艳  姜在兴  师晶  徐杰 《沉积与特提斯地质》2010,30(4):19-23

东辛油田沙三中亚段发育大量与三角洲前缘滑塌相伴生的坡移浊积扇、滑塌浊积扇、远源浊积岩以及洪水成因的水下碎屑流,发育岩性油藏及岩性-构造油藏。纵向上,湖退体系域早期准层序组PS7～PS5是最主要的油气富集层位,其次为湖侵体系域PS8;平面上,各准层序组西部油气富集程度好于东部,含油储层主要为滑塌浊积扇及部分远源浊积岩,其次为坡移浊积扇。油气分布主要受宏观沉积相带、构造、微观储集物性和成岩作用等多种因素控制,距油源远近控制油藏纵向有利层位,砂体成因类型控制着平面有利区带。  相似文献   

Turbidite system architecture and sedimentary processes along topographically complex slopes: the Makran convergent margin     

JULIEN BOURGET  SEBASTIEN ZARAGOSI  NADINE ELLOUZ‐ZIMMERMANN  NICOLAS MOUCHOT  THIERRY GARLAN  JEAN‐LUC SCHNEIDER  VALENTINE LANFUMEY  SIGFRIED LALLEMANT 《Sedimentology》2011,58(2):376-406

This study investigates the morphology and Late Quaternary sediment distribution of the Makran turbidite system (Makran subduction zone, north‐west Indian Ocean) from a nearly complete subsurface mapping of the Oman basin, two‐dimensional seismic and a large set of coring data in order to characterize turbidite system architecture across an active (fold and thrust belt) margin. The Makran turbidite system is composed of a dense network of canyons, which cut into high relief accreted ridges and intra‐slope piggyback basins, forming at some locations connected and variably tortuous paths down complex slopes. Turbidite activity and trench filling rates are high even during the Holocene sea‐level highstand conditions. In particular, basin‐wide, sheet‐like thick mud turbidites, probably related to major mass wasting events of low recurrence time, drape the flat and unchannellized Oman abyssal plain. Longitudinal depth profiles show that the Makran canyons are highly disrupted by numerous thrust‐related large‐scale knickpoints (with gradients up to 20° and walls up to 500 m high). At the deformation front, the strong break of slope can lead to the formation of canyon‐mouth ‘plunge pools’ of variable shapes and sizes. The plunge pools observed in the western Makran are considerably larger than those previously described in sub‐surface successions; the first insights into their internal architecture and sedimentary processes are presented here. Large plunge pools in the western Makran are associated with large scoured areas at the slope break and enhanced sediment deposition downstream: high‐amplitude reflectors are observed inside the plunge pools, while their flanks are composed of thin‐bedded, fine‐grained turbidites deposited by the uppermost part of the turbidity flows. Thus, these architectural elements are associated with strong sediment segregation leading to specific trench‐fill mechanisms, as only the finer‐grained component of the flows is transferred to the abyssal plain. However, the Makran accretionary prism is characterized by strong along‐strike variability in tectonics and fluvial input distribution that might directly influence the turbidite system architecture (i.e. canyon entrenchment, plunge pool formation or channel development at canyon mouths), the sedimentary dynamics and the resulting sediment distribution. Channel formation in the abyssal plain and trench‐fill characteristics depend on the theoretical ‘equilibrium’ conditions of the feeder system, which is related closely to the balance between erosion rates and tectonic regime. Thus, the Makran turbidite system constitutes an excellent modern analogue for deep‐water sedimentary systems with structurally complex depocentres, in convergent margin settings.  相似文献   

Propagation of the Storegga tsunami into ice‐free lakes along the southern shores of the Barents Sea     

Anders Romundset  Stein Bondevik 《第四纪科学杂志》2011,26(5):457-462

Deposits in coastal lakes in northernmost Norway reveal that the Storegga tsunami propagated well into the Barents Sea ca. 8100–8200 years ago. A tsunami deposit – found in cores from five coastal lakes located near the North Cape in Finnmark – rests on an erosional unconformity and consists of graded sand layers and re‐deposited organic remains. Rip‐up clasts of lake mud, peat and soil suggest strong erosion of the lake floor and neighbouring land. Inundation reached at least 500 m inland and minimum vertical run‐up has been reconstructed to 3–4 m. In this part of the Arctic coastal lakes are usually covered by >1 m of solid lake ice in winter. The significant erosion and deposition of rip‐up clasts indicate that the lakes were ice free and that the ground was probably not frozen. We suggest that the Storegga slide and ensuing tsunami happened sometime in the summer season, between April and October. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

地幔流体及其成矿作用   总被引：50，自引：2，他引：50  

刘丛强  黄智龙  李和平  苏根利 《地学前缘》2001,8(4):231-243

地幔流体及其成矿作用的研究是当前地学界倍受关注的前沿课题。地幔流体是一种以CO2和H2 O为主、同时含有一定量的溶质成分、相对富集大离子等不相容元素的超临界流体 ,具有独特的溶解和输运能力 ,主要来源于俯冲板块的脱水、脱气作用和地核及地幔脱气作用。地幔流体在许多大型—超大型金属、非金属、油气矿床和矿集区形成过程中具有重要意义。地幔流体成矿作用主要表现为本身成矿、提供成矿物质、成矿流体和成矿热动力。地质构造背景、岩浆活动、矿床地质、矿床地球化学等方面的研究均可提供地幔流体成矿作用的证据。地幔流体成矿作用的主要特征是矿床具有深大断裂构造背景、伴随幔源岩浆活动、成矿物质和成矿流体具有幔源性、往往形成大型—超大型矿床和矿集区  相似文献   

新疆东准噶尔中酸性浅成岩金、铜成矿系列   总被引：4，自引：0，他引：4       下载免费PDF全文

廖启林  蒋少涌 《地质找矿论丛》2001,16(1):7-11,46

中酸性浅成岩金，铜矿床是新疆东准噶尔地区一个重要的新成矿系列，通过总结有关中酸性小岩体及其典型矿床的基本特征，将该成矿系列划分为浅成岩－构造蚀变岩型金矿，类夕卡岩型铜钼矿，细脉浸染型（斑岩型）铜，金矿及隐爆角砾岩型脉状铜矿等基本矿化类型，并探讨了有关典型矿床的REE特征，建立了该成矿系列的总体成矿模式，认为该成矿系列受控于海西中晚期的中酸性浅成小杂岩体，其岩石化学成分，REE特征及成矿作用方式具有明显的相似性。  相似文献   

论新疆东准噶尔陆相火山成矿作用   总被引：6，自引：0，他引：6  

刘家远 《大地构造与成矿学》2001,25(4):434-438

早石炭世晚期至早二叠世时期，东准噶尔地区陆相火山作用广为发育。近年来的研究证明，这一时期的陆相火山作用形成了两套重要的成矿岩浆建造，即安山－英安质喷溢、喷发岩建造和中性－中酸性潜火山杂岩建造，它们具有同一的成矿专属性，与金、铜、铁成矿密切相关。前者主要形成特征的浅成低温热液陆相火山岩型金矿。后者与金、铜成矿关系极为密切，其突出特征表现为受同－成矿岩浆作用的制约，在不同的外部条件下，形成不同类型的多种矿床，分别构成自成体系的金矿床系列和铜矿床系列，充分揭示了东准噶尔与陆相火山作用有关金、铜成矿的广阔前景和深远意义。  相似文献   

贵州省贞丰县岩上金矿床地质特征   总被引：9，自引：7，他引：9  

刘建中 《贵州地质》2001,18(3):174-178

贞丰岩上金矿床为灰家堡金矿田的组成部分。经3年的地质勘查工作，初步查明其规模已达大型矿床，有望达成超大型金矿床，本文较详细地论述了矿床的地质特征，初步探讨了矿床成因、并指出了寻找同类型矿床的工作靶区。  相似文献