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1.
我国原生锰矿床的沉积建造及形成环境 总被引：3，自引：1，他引：3
文中将我国含锰建造分为炭质泥岩建造、粉砂-泥质岩建造、硅质岩建造、碳酸盐岩建造、喷发-沉积建造和湖相沉积建造.介绍了各建造的特征和形成环境.认为它们可形成于多种沉积区,而非单一的陆缘滨海环境;其物质来源也是复杂多样的. 相似文献
2.
中国晚震旦—古生代海相含铀碳硅泥岩沉积建造及主要含铀层 总被引：1，自引：0，他引：1
中国海相碳硅泥岩含铀沉积建造中产有重要铀矿床。这些建造是:地台区(或准地台区)及构造过渡区稳定型及过渡型含铀建造;地槽区活动型含铀建造。属前者的有中国各地台边缘及其相邻构造带中,发育在前寒武基底之上的,震旦-寒武纪以炭质页岩和碳硅泥岩过渡型沉积为主的含铀建造,以及发育在加里东褶皱基底之上的以碳酸盐沉积为主的晚古生代含铀建造。活动型含铀建造主要有发育于加里东冒地槽沉积区的寒武-志留纪炭质页岩、炭硅质页岩建造及早中志留世硅质岩建造及碎屑岩-硅灰质岩建造。文中还评述了我国碳硅泥岩主要含铀层的分布及其意义。 相似文献
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本文在综合部分沉积型工业锰矿床矿物相特征的基础上,试就主要锰碳酸盐的矿物测定、沉积物理化学环境、分带特征的地质应用,谈几点粗浅认识.沉积锰矿床的矿物相特征1.矿石中锰矿物的组成据实验室矿物相分析查定,已知的若干沉积型工业锰矿床中原生沉积含锰矿物有:菱锰矿、钙菱锰矿、锰方解石、含锰方解石、镁菱锰矿、镁钙菱锰矿、镁锰云石、锰云石、铁菱锰矿、含铁菱锰矿、锰铁白云石、锰菱铁矿等.以上表明,矿石中的沉积含锰矿物基本上是由二价锰碳酸盐类矿物组成,且锰、钙、镁、铁普遍具有类质同象替换的特点. 相似文献
4.
新疆北部早石炭世沉积建造及其形成的大地构造环境 总被引：1，自引：0，他引：1
张琴华 《大地构造与成矿学》1991,15(2):128-136
本文详细地研究了新疆北部早石炭世发育的三类沉积建造:碳酸盐建造、陆屑建造和火山-沉积建造,并进行了建造区的划分,据此论述了早石炭世新疆北部的大地构造环境及其分区。 相似文献
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古天然气渗漏沉积型锰矿床成矿系统与成矿模式——以黔湘渝毗邻区南华纪“大塘坡式”锰矿为例 总被引：20，自引：2，他引：18
黔湘渝毗邻区"大塘坡式"锰矿床形成于南华纪裂谷盆地中,矿床主要分布于裂谷盆地中的次级断陷沉积盆地中心,受古断裂控制。矿物成分主要是菱锰矿和钙菱锰矿,具有低δ13C值(-7‰～-10‰)、高δ34S值(+40‰～+63‰)的特征。含锰岩系中,碳质页岩的Mn/Cr比值在40左右。结合菱锰矿体及相邻岩层中普遍发育由古天然气泄漏沉积形成的气泡状构造、底辟构造、渗漏管构造、帐篷构造、泥火山构造及相关的软沉积变形纹理等特征,提出该地区南华纪"大塘坡式"锰矿床是古天然气渗漏沉积成矿成因,并建立了古天然气渗漏沉积型锰矿床成矿系统与成矿模式。 相似文献
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辽河群镁质碳酸盐建造及其非金属矿产 总被引：3，自引：0，他引：3
辽河群镁质碳酸盐岩系，含矿岩石组合有黑尔峪组镁质碳酸盐含矿建造和大石桥组镁质碳酸盐含矿建造。其中由区域变质作用形成的白云石－滑石－菱镁矿、滑石－菱镁矿－透闪石、滑石－菱镁矿－水镁石－蛇纹石和硼矿物－蛇纹石－菱镁石－水镁石－滑石－金云母－透辉石等４种矿床组合形式，构成规律明显，经济价值大的非金属成矿系列。 相似文献
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结合矿床地质背景，从时间空间分布，晶体形态，显微镜鉴定，X射线衍射曲线，电子探针分析和化学成分等方面对碳酸盐锰矿半氧化带中的菱锰矿进行了比较详细的研究。 相似文献
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晶质菱镁矿矿床赋存于海相碳酸盐岩建造,为富镁碳酸盐经后期变质重结晶的产物,属沉积- 变质型矿床。本次研究将中国境内的晶质菱镁矿矿床按变质重结晶程度分为三类 (高、中和低),并进行了地质和地球化学研究,获得如下认识：① 产于古生代海相碳酸盐岩中的菱镁矿矿床经历低程度变质重结晶作用(绿片岩相),矿石结晶度差,品位相对较低(44. 98%~47. 35%),且保留有海相碳酸盐岩建造的碳同位素地球化学特征(δ13CV- PDB：0. 4‰~+0. 3‰);② 大型(>5000万t)优质(MgO>46%)晶质菱镁矿矿床集中分布在华北克拉通东部的古元古代胶- 辽- 吉活动带海相碳酸盐岩中,矿体后期经历中等程度变质重结晶作用(中—低角闪岩相),矿石发生中等程度的重结晶作用,继承了海相碳同位素地球化学特征(δ13CV- PDB1. 9‰~+1. 7‰);③ 经历高角闪岩相(高级)变质作用的菱镁矿矿床矿石结晶程度最优,但强烈的变质作用引发外源含硅热液流体加入而发生蛇纹石化作用,矿石品位低(MgO=44. 42%~45. 55%),具有较高的TFeO、Mn和Ti含量,整体亦显示较低的碳同位素组成(δ13CV- PDB：4. 1‰~3. 5‰)。因此,沉积- 变质型菱镁矿矿体的镁质富集可能发生在海相沉积成岩期,后期变质作用引发富镁碳酸盐矿物重结晶作用,镁质碳酸盐和钙质碳酸盐矿物进一步发生近原地分离重结晶作用,形成晶质菱镁矿矿体和富镁白云石夹石,但过高(高角闪岩相及以上)或过低(绿片岩相)的变质作用可能均不利于形成大型优质晶质菱镁矿矿床。 相似文献
10.
鲁西是山东省古生代非金属矿的重要产区。自寒武纪早期至二叠世晚期，形成了海相－海陆交互相－陆相沉积地层及一系列非金属矿沉积建造，有“寒武纪的石砂岩、石膏、石灰岩、泥灰岩、木鱼石等含矿沉积建造；山东古代生非金属含矿沉积建造的总结构和研究，对有关非金属矿产的开发应用和普查找矿具有重要意义。 相似文献
11.
Emily Keeble David I. Whiteside Michael J. Benton 《Proceedings of the Geologists' Association. Geologists' Association》2018,129(2):99-119
Pant-y-ffynnon Quarry in South Wales yielded a rich cache of fossils in the early 1950s, including articulated specimens of new species (the small sauropodomorph dinosaur Pantydraco caducus and the crocodylomorph Terrestrisuchus gracilis), but no substantial study of the wider fauna of the Pant-y-ffynnon fissure systems has been published. Here, our overview of existing specimens, a few described but mostly undescribed, as well as freshly processed material, provides a comprehensive picture of the Pant-y-ffynnon palaeo-island of the Late Triassic. This was an island with a relatively impoverished fauna dominated by small clevosaurs (rhynchocephalians), including a new species, Clevosaurus cambrica, described here from a partially articulated specimen and isolated bones. The new species has a dental morphology that is intermediate between the Late Triassic Clevosaurus hudsoni, from Cromhall Quarry to the east, and the younger C. convallis from Pant Quarry to the west, suggesting adaptive radiation of clevosaurs in the palaeo-archipelago. The larger reptiles on the palaeo-island do not exceed 1.5?m in length, including a small carnivorous crocodylomorph, Terrestrisuchus, and a possible example of insular dwarfism in the basal dinosaur Pantydraco. 相似文献
12.
Gilles Serge Odin 《Comptes Rendus Geoscience》2002,334(6):409-414
Lithostratigraphy, physicochemical stratigraphy, biostratigraphy, and geochronology of the 77–70 Ma old series bracketing the Campanian–Maastrichtian boundary have been investigated by 70 experts. For the first time, direct relationships between macro- and microfossils have been established, as well as direct and indirect relationships between chemo-physical and biostratigraphical tools. A combination of criteria for selecting the boundary level, duration estimates, uncertainties on durations and on the location of biohorizons have been considered; new chronostratigraphic units are proposed. The geological site at Tercis is accepted by the Commission on Stratigraphy as the international reference for the stratigraphy of the studied interval. To cite this article: G.S. Odin, C. R. Geoscience 334 (2002) 409–414. 相似文献
13.
The effect of water on accessory phase solubility in subaluminous and peralkaline granitic melts 总被引：4，自引：0，他引：4
The solubilities of columbite, tantalite, wolframite, rutile, zircon and hafnon were determined as a function of the water contents in peralkaline and subaluminous granite melts. All experiments were conducted at 1035 °C and 2 kbar and the water contents of the melts ranged from nominally dry to approximately 6 wt.% H2O. Accessory phase solubilities are not affected by the water content of the peralkaline melt. By contrast, solubilities are affected by the water content of the subaluminous melt, where the solubilities of all the accessory phases examined increase with the water content of the melt, up to 2 wt.% H2O. At higher water contents, solubilities are nearly constant. It can be concluded that water is not an important control of accessory phase solubility, although the water content will affect diffusivities of components in the melt, thus whether or not accessory phases will be present as restite material. The solubility behaviour in the subaluminous and peralkaline melts supports previous spectroscopic studies, which have observed differences in the coordination of high field strength elements in dry vs. wet subaluminous granitic glasses, but not for peralkaline granitic glasses. Lastly, the fact that wolframite solubility increases with increasing water content in the subaluminous melt suggests that tungsten dissolved as a hexavalent species. 相似文献
14.
Muriel Rocher Stéphane Baize Stéphane Jaillet Edward Marc Cushing Yannick Lozac&#x;h Francis Lemeille 《Comptes Rendus Geoscience》2003,335(8):701-708
Calcite samples were extracted both from the rock matrix and the superficial coating of a karstified fault plane of an underground quarry, located in the eastern border of the Paris basin. The karstification is dated as Quaternary. Analysis of mechanical calcite twinning reveals that only the calcite matrix has also undergone a compression trending WNW that can be attributed to the Mio-Pliocene alpine collision. Both coating and matrix have undergone a strike-slip regime with σ1 roughly trending north–south, that could correspond to the regional present-day state of stress, a strike-slip compression rather trending NNW, modified by local phenomena. To cite this article: M. Rocher et al., C. R. Geoscience 335 (2003). 相似文献
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正20141756 Chen Ruige(Mathematical College,China University of Geosciences,Beijing100083,China);Zhou Xun Numerical Simulation of Groundwater Level Fluctuation in a Coastal Confined Aquifer with Sloping Initial Groundwater Level Induced by the Tide(Geological Bulletin of China,ISSN1671-2552,CN11-4648/P,32(7),2013,p.1099-1104,6 illus.,16 refs.) Key words:confined water,groundwater level 相似文献
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正20141408 Cai Jia(Institute of Geology,Chinese Academy of Geological Sciences,Beijing100037,China);Liu Fulai Petrogenesis and Metamorphic P-T Conditions of Garnet-Spinel-Biotitebearing Paragneiss in Danangou Area,Daqingshan-Wulashan Metamorphic Complex Belt(Acta Petrologica Sinica,ISSN1000-0569,CN11-1922/P,29(7), 相似文献
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正20142386An Guoying(China Aero Geophysical Survey and Remote Sensing Center for Land and Resources,Beijing 100083,China)Application of Satellite Remote Sensing in Regional Hydrogeological Investigation:Taking Cenozoic Strata in Wenquan Sheet(1∶250 000)of Karakoram Range as an Example(Geosci- 相似文献
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正20141016An Chengbang(Key Laboratory of Western China’s Environmental Systems,Ministry of Education,Lanzhou University,Lanzhou 730000,China);Zhao Yongtao Lake Records during the Last Glacial Maximum from Xinjiang,NW China and Their Climatic Impli- 相似文献
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正20141538 Cao Qing(School of Earth Sciences and Engineering,Xi’an Petroleum University,Xi’an 710065,China);Zhao Jingzhou Characteristics and Significance of Fluid Inclusions from Majiagou Formation,Yichuan Huangling Area,Ordos Basin(Advances in Earth Science,ISSN1001-8166,CN62-1091/P,28(7),2013,p.819-828,7 illus.,3 tables,43 refs.) 相似文献