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1.
中国金刚石砂矿主要分布在华北与扬子地台郯庐断裂区与沅水流域区 ,在大别山区及新疆、西藏超基性岩附近也有分布。不同时代的含金刚石金伯利岩或超基性岩带 ,经风化、剥蚀、搬运 ,形成含金刚石砂矿中间储存体 ,在水系中下游形成不同类型 (阶地、河谷、河床 )砂矿。金刚石砂矿找矿方向应是模式找矿主要有三方面 :一是矿源 ,二是中间储存体 ,三金刚石砂矿组合矿物。 相似文献
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安徽宿州栏杆地区含金刚石的岩体是通过验证地磁异常而发现的.该地区钻孔资料显示含金刚石岩体均为基性辉绿岩,但含矿层与磁异常并非完全一一对应.文章结合钻孔与磁测资料就含金刚石岩体与磁异常的关系进行了分析,认为通过磁异常找矿是该区寻找金刚石的有效途径,但同时应注意对非磁性含金刚石岩体的研究. 相似文献
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扬子克拉通金刚石原生矿找矿问题一直是极具争议和挑战性的课题,而贵州镇远作为扬子克拉通最丰富的含金刚石母岩出露区,对该区岩体侵位模式及找矿前景的研究,可为扬子克拉通金刚石成矿与找矿研究、地球深部重大科学问题探讨等提供新的思路和方法。通过梳理分析以往该区形成的勘查、研究资料,认为贵州东部所出露的一系列钾镁煌斑岩体受控于北东向的玉屏-施洞-三都断裂,就镇远马坪而言,至少出露2期钾镁煌斑岩侵入活动,在其深冲断层东侧可能存在未被剥蚀的岩体,仍具有一定的找矿前景。 相似文献
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地质经济学关注地质科学研究和矿产勘查经费使用的有效性,是使科研的成果更有意义、更具创新性、找矿更具有针对性。含金刚石的金伯利岩体是世界上分布较少和较难寻找的岩体,但地质学家却做了大量的和深入的研究。从消化全球科学研究成果、建立金刚石矿勘查靶区、利用指示矿物追踪、消除干扰体,进而用多种手段确定靶位,建立了一套科研成果用于找矿的行之有效的步骤,进行每一个步骤时都要考虑到资金使用的有效性。本文讨论地质经济学在寻找含金刚石的金伯利岩全过程中的应用,抛砖引玉,认为地质经济学应当贯穿在科研和找矿的各个方面。本文还对中国寻找金刚石矿的远景区进行了分析。 相似文献
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鲁西大井头地区自然重砂中的金刚石及其找矿指示矿物发现已久,然而找矿工作尚未能取得实质性突破。本文从金刚石找矿指示矿物角度入手,在研究该地区指示矿物晶体形貌特征和化学成分特征的基础上,通过对比大井头地区自然重砂与大井头岩体中的指示矿物特征、大井头地区与其它地区金伯利岩、钾镁煌斑岩中的指示矿物特征后得出：大井头地区既存在金刚石指示矿物,又含有金刚石母岩指示矿物,是鲁西金刚石找矿的有利地区;第四系自然重砂中的指示矿物类型和所占比重与大井头岩体较为一致,认为第四系中的指示矿物由大井头岩体供源;大井头岩体含有较大比重的榴辉岩相指示矿物,如G4组镁铝- 铁铝榴石和绿辉石,且其中金刚石多为Ib型,表现出与蒙阴地区金刚石原生矿不同的特征,认为大井头岩体为穿越金刚石生成区边部、并携带了其中特征性矿物成分的钾镁煌斑岩。结合大井头周边地区发现的三处重砂矿物异常和多个可疑岩体,依据钾镁煌斑岩集群分布的特点,认为大井头及周边地区是新区、新类型金刚石找矿的优质靶区,建议今后找矿方向和工作重点向钾镁煌斑岩型金刚石原生矿转移。 相似文献
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塔里木盆地西南缘金刚石找矿前景及其预测 总被引：1，自引：0，他引：1
在前人地质、地球物理资料和部分研究成果的基础上，通过大地构造背景条件的对比、区域重力、航磁资料的综合分析，特别是通过深源岩浆活动特征的分析，深入研究了塔里木盆地西南缘金刚石成矿地质条件。并且通过金刚石找矿基本和上述研究成果，以及金刚石指示矿物特征的分析，对和田地区金刚石成矿区范围、金刚石母岩岩性及其含矿性、出土金刚石的源区位置以及金刚石找矿方向进行了预测，并将金刚石成矿预测区分为南北两段，分别对其找矿前景进行了预测。 相似文献
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贵州镇远马坪地区作为中国第一个含金刚石母岩——钾镁煌斑岩的发现地,既是华南地区最重要的、最丰富的含金刚石母岩出露区,也是中国金刚石原生矿找矿的重点区域。以往针对该区的金刚石原生矿勘查工作重点多集中于对其寄主岩石特征的研究上,如岩体侵位方式、矿物组成、岩石地球化学特征以及侵位时代等方面（卢登蓉等,1989;罗会文等,1989;江万,1995;方维萱等,2002;杨光忠,2013）,而对于金刚石本身晶貌学特征的研究较少,且受当时测试技术条件的限制,有关金刚石晶貌特征所对应的找矿信息揭示不够充分。鉴于扬子地台金刚石找矿工作的迫切需要,本文通过对镇远地区钾镁煌斑岩中金刚石矿物自身特点开展晶貌学研究,进而反演、推测其结晶和生长过程,并由此探讨寄主岩石源区特征、母岩形成条件,为扬子地台金刚石原生矿找矿研究提供新的思路。 相似文献
9.
金刚石是工业和国防科技不可缺少的重要材料，具有广泛的用途。一个国家金刚石的需要量标志着该国工业化的水平。我国是一个天然金刚石的进口国，已探明的储量远不能满足工业增长的需要。必须加快找矿步伐。天然金刚石形成于亏损型上地幔，这种亏损型上地幔是太古代基性岩浆大量喷发造成的。含有金刚石的古克拉通及其下伏的上地幔上部称为“含金刚石区”，含金刚石区（岩石圈）具有“老、厚、冷、干、脆”的特点。文章试图通过与世界典型含金刚石区的区域背景条件的对比，来说明华北地台内蒙古部分具有相同的形成金刚石的背景条件，并初步认为在内蒙古华北地台范围内存在南部、中部及北部三个成矿条件较好的找矿远景区。 相似文献
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Coal fires in China consume vast amounts of fuel and cause serious environmental problems. Most of these coal fires are related to mining activity. However, naturally produced palaeo coal fires in Xinjiang, north‐west China, have been recognized via burnt rocks. The burnt rocks in the study area are found at different river terraces underlying unburnt alluvial and river terrace deposits. Several age groups of coal fires have been identified based on the positions of burnt rocks at river terraces and the relationship between the burnt rocks and the terrace deposits. These palaeo coal fires are: (1) Pliocene – Early Quaternary in age at 200 m above present river terrace deposits; (2) Middle Pleistocene in age, at > 90 m; (3) Late Pleistocene, at 90–70 m; (4) Holocene; (5) burnt rocks relating to active coal fires. Palaeomagnetic data of the burnt rocks from different terraces give normal remanent magnetization and help further to constrain the ages of the coal fires. 相似文献
12.
以小盆湖砂金矿床为典型的一系列砂金矿床。矿点在藏北羌 塘中部构成一个呈东西向的砂金矿带，笔者1999年首次将其命名为“藏北羌塘小盆湖-拉雄错砂金矿带”。通过对小盆湖砂金矿床基岩地质，地貌，第四纪地质，矿床类型，成因类型，矿体特征，砂金特征的全面介绍及与该带其它砂金矿床，矿点的对比，结合区域地质背景，认为前泥盆系阿木岗群和石炭系中的火山岩层位是主要矿源层，此后若干不同时期的沉积不整合界面，都表征着其下古风化壳，其上底部碎屑岩的含金物聚源区可以直接或经改造就近形成金矿矿床，羌塘中央隆起带及其两侧和东西方向石炭系分布区具有广阔的金矿找矿前景。 相似文献
13.
大兴安岭哈拉哈河-绰尔河第四纪火山分期: K-Ar年代学与火山地质特征 总被引：9，自引：6，他引：3
大兴安岭中部哈拉哈河-绰尔河第四纪火山区分布有34座火山,这些火山总体呈北东向带状分布,火山岩分布面积约400 km2,岩性主要为碱性橄榄玄武岩.根据火山地质特征,结合火山岩K-Ar测年结果,哈拉哈河-绰尔河第四纪火山可进一步划分为早、中、晚更新世和全新世4期.早更新世火山岩,由于被后期火山岩覆盖,主要分布于火山区周边和出露在河谷中.中更新世火山活动最强,不论火山数量(27座)还是熔岩流规模都超过该区第四纪火山的一半以上.晚更新世时期火山活动趋弱,火山活动范围缩小,只局限于小范围区域.全新世火山活动又进入新的高峰期,强爆破式喷发和规模宏大的熔岩流,以及保存完好的熔岩流地貌是全新世火山之特点. 相似文献
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20世纪90年代初,加拿大地质学家Charles E Fipke先生在加拿大高寒的Lac De Gras地区发现的含金刚石的金伯利岩,把加拿大带入了寻找金刚石矿的高潮,相继在Lac De Gras地区发现金伯利岩管群和在加拿大中部的Fort à la Corne发现的金伯利岩群,使得加拿大金刚石产量位居世界第三。本文综述这两个地区金刚石矿的发现和分析含金刚石的金伯利岩的存在的特征,指出太古宙地台环境是含金刚石的金伯利岩存在的基础,厚度大的太古宙地台底部是金刚石晶体缓慢生长的天然高温高压培育仓、沿冰碛或沿水系沉积物追踪金伯利岩指示矿物是溯源金刚石母岩的手段、认识金伯利质火山地貌形态能起到在寻找金伯利质火山位置过程中事半功倍的效果,有助于理解金伯利质火山口相的变化。 相似文献
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V. T. Ishmukhametova 《Moscow University Geology Bulletin》2016,71(5):368-371
An essentially new method for the allocation of diamondiferous kimberlite pipes against surrounding rocks is proposed. The method is based on the interpretation of multispectral LANDSAT-7 ETM+ satellite images; it allows one to find the most promising areas within perspective sites revealed by other methods. It is demonstrated that application of GIS technologies for comprehensive use of geological, geophysical, and mineralogical data and the results of the interpretation of satellite images is efficient for predicting kimberlite diamond deposits in both studied areas and poorly explored territories. 相似文献
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确定大江大河防洪堤高度应考虑地面沉降因素——对1998中国大洪水的反思 总被引：8，自引：0，他引：8
世界上抽汲地下水或石油引起地面沉降正越来越普遍。大江大河防洪能力降低是地面沉降灾害现象之一。上海因地面沉降产生严重的洪涝灾害,上海外滩防汛墙高度的主要决定因素是地面沉降。沙市、武汉、哈尔滨和大庆等城市和地区是我国1998年夏特大洪水的重灾地区,这些城市和地区实际上已存在地面沉降问题。几十年来产生的地面沉降很可能已降低了这些地区江河大堤的防洪能力,从而加重了这次洪涝灾害。建议在确定大江大河防洪堤高度应考虑地面沉降因素,并尽快对重点城市和地区进行地面沉降调查与预测研究。 相似文献
17.
金刚石及其寄主岩石是人类认识地球深部物质组成和性质、壳幔和核幔物质循环重要研究对象。本文总结了中国不同金刚石类型的分布,着重对比了博茨瓦纳和中国含金刚石金伯利岩的地质特征,取得如下认识:(1)博茨瓦纳含矿原生岩石仅为金伯利岩,而中国含矿岩石成分复杂,金伯利岩主要出露在华北克拉通,展布于郯庐、华北中央和华北北缘金伯利岩带,具有工业价值的蒙阴和瓦房店矿床分布于郯庐金伯利岩带中;钾镁煌斑岩主要出露在华南克拉通,重点分布在江南和华南北缘钾镁煌斑岩带中;(2)钙钛矿原位U-Pb年龄和Sr、Nd同位素显示,86～97 Ma奥拉帕金伯利岩群和456～470 Ma蒙阴和瓦房店金伯利岩均具有低87Sr/86Sr(0.703～0.705)和中等εNd(t)(-0.09～+5)特征,指示金伯利岩浆源自弱亏损地幔或初始地幔源区;(3)博茨瓦纳金伯利岩体绝大多数以岩筒产出,而中国以脉状为主岩筒次之;博茨瓦纳岩筒绝大部分为火山口相,中国均为根部相,岩筒地表面积普遍小于前者;(4)奥拉帕A/K1和朱瓦能金伯利岩体是世界上为数不多的主要产出榴辉岩捕虏体和E型金刚石的岩筒之一,而同位于奥拉帕岩群的莱特拉卡内、丹姆沙和卡罗韦岩体与我国郯庐带的金伯利岩体类似,均主要产出地幔橄榄岩捕虏体以及P型和E型金刚石;(5)寻找含矿金伯利岩重点注意以下几点:克拉通内部和周缘深大断裂带是重要的控岩构造;镁铝榴石、镁钛铁矿、铬透辉石、铬尖晶石和铬金红石等是寻找含金刚石金伯利岩重要的指示矿物;航磁等地球物理测量需与土壤取样找矿方法相结合才能取得更好效果;(6)郯庐金伯利岩带、江南钾镁煌斑岩带和塔里木地块是中国重要含矿岩石的找矿靶区,冲积型金刚石成矿潜力巨大。 相似文献
18.
This study reviews the Quaternary alluvial stratigraphy in three semi-arid river basins of western India i.e., lower Luni
(Rajasthan), and Mahi and Sabarmati (Gujarat alluvial plains). On the basis of OSL chronologies, it is shown that the existing
intra-valley lithostratigraphic correlations require a revision. The sand, gravel and mud facies are present during various
times in the three basins, however, the fluvial response to climate change, and the resulting facies associations, was different
in the Thar desert as compared to that at the desert margin; this makes purely lithostratigraphic correlations unviable. It
is further shown that the rivers in the Thar desert were more sensitive to climate change and had small response times and
geomorphic thresholds as compared to the desert-margin rivers. This is illustrated during the early OIS 1, when the Luni river
in the Thar desert was dynamic and showed frequent variations in fluvial styles such as gravel bedload braided streams, sand-bed
ephemeral streams and meandering streams, all followed by incision during the early Holocene. The coeval deposits in Sabarmati,
however, only show a meandering, floodplain-dominated river.
Late Quaternary alluvial deposits in these basins unconformably overlie some older deposits that lack any absolute chronology.
Based on the facies types and their associations, and the composition and architecture of the multistoried gravel sheets in
the studied sections, it is suggested that older deposits are of pre-Quaternary age. This hypothesis implies the presence
of a large hiatus incorporating much of the Quaternary period in the exposed sections 相似文献
19.
Surajit Misra Sukanta Roy Vikrant Bartakke Gaurav Athavale Harsh Gupta 《Journal of the Geological Society of India》2017,89(2):131-132
Mn-rich ilmenites (up to 7 % MnO) have been identified in dykes cutting the Malanjkhand porphyry copper mining area in Madhya Pradesh. The dykes are hydrothermally altered and are of tholeiitic affinities. Lamprophyres have been reported from nearby areas. The presence of Mn-rich Ilmenites in the Malanjkhand copper mine dykes and the occurrence of lamprophyres and the pervasive potassium metasomatism in the area strongly suggests a possibility of finding diamondiferous rocks in the area. Such high-Mn bearing ilmenites are associated with diamondiferous deposits in other parts of the world, e.g. Juina kimberlites, Brazil. Mn-bearing ilmenite is considered as an indicator mineral for kimberlite/diamond occurrences. The presence of kimberlite pipes in Raipur district and the association of Mn-rich ilmenite with kimberlites is a fortuitous coincidence for venture-some mining companies. A probable explanation for the origin of manganese layers in the context of ‘rift’ tectonic environment is offered. Also a possible link between the dykes, quartz veins in the Malanjkhand granitic rocks and the copper mineralization is proposed. 相似文献
20.
V. B. Vasilenko L. G. Kuznetsova A. V. Tolstov V. A. Minin 《Geochemistry International》2012,50(12):988-1006
430 chemical analyses of rocks and their diamondiferous potential are used to identify correlations between the diamondiferous potential of rocks and their petrochemical parameters. Samples for this research were collected from selected intervals of core materials, which were also examined for diamond content (a few samples from each interval), from the Nyurbinskaya, Botuobinskaya, Internatsional??naya, Mir, Aikhal, Yubileinaya, Satykanskaya, Udachnaya-West, and Udachnaya-East pipes. Typochemical indications of diamondiferous potential are TiO2 and K2O concentrations and the CaO/MgO ratio. System models developed for diamondiferous kimberlites allowed distinguishing two trends of their compositional variability. One of the trends is defined by the negatively correlated TiO2 and K2O concentrations of the rocks. This trend is discrete and can be statistically justifiably subdivided into seven segments, each of which represents a population of compositions produced under similar physicochemical conditions. Experimental data confirm that this trend can be closely related to the diamondiferous potential. Diamond richest kimberlites are practically free of TiO2, whereas diamond poorest ones contain as much as 3% of this oxide. The former and the latter rocks were produced at the greatest and shallowest depths, respectively. The other trend is exhibited in all populations and subdivides them into discrete groups (varieties of the populations) with systematically decreasing CaO/MgO ratio. This parameter is nonlinearly correlated with the diamondiferous potential, and its increase corresponds to a systematic increase in the melting temperature of the source material. Certain kimberlite populations contain anomalously high K2O concentrations, perhaps, because of mantle metasomatism or the presence of fragments of oceanic crustal material in the magma generation region. In these instances, numerous diamonds could crystallize in the parental melts under high pressures (>100 kbar). The paper presents statistical analysis of pair regressions of the contents of indicative oxides and diamondiferous potential and a graphical multiple-link model for correlations between concentrations of major oxides and diamondiferous potential. Tests of the predictions of diamondiferous potential on the basis of chemical parameters confirm that these predictions are accurate in 85?C90% of the instances. 相似文献