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1.
羌塘盆地区域地质调查成果与进展   总被引:2,自引:2,他引:2  
北部可可西里-金沙江结合带与南部班公湖-怒江结合带之间的羌塘盆地主要涉及的1:25万区域地质调查图幅有乌兰乌拉湖幅、赤布张错幅和兹格塘错幅(2000—2002年),取得的主要进展如下。  相似文献   

2.
班公湖-怒江结合带区域地质调查成果与进展   总被引:1,自引:0,他引:1  
班公湖-怒江结合带是一条非常重要的大地构造界线,由西往东延伸并向南折拐,贯穿于整个青藏高原中部,主要涉及的1:25万区调图幅有尼玛区幅、多巴区幅、班戈县幅和兹格塘错幅(2000-2002年),取得的主要进展如下。  相似文献   

3.
藏北南羌塘孜狮桑地区早三叠世牙形刺化石新资料   总被引:1,自引:2,他引:1  
笔者在藏北开展1 :25万帕度错幅区域地质调查过程中,在达杂迪扎错北面孜狮桑测制地层剖面时发现了产早三叠世牙形刺化石(图版Ⅰ)的地层,并新建立了孜狮桑组。孜狮桑位于羌塘盆地中央隆起带的南边,地层区划隶属于羌塘-保山地层区多玛地层分区。孜狮桑组地层层序如下(图1)。  相似文献   

4.
长江源美杜塘一带发现古近纪双壳类化石   总被引:1,自引:1,他引:1  
长江源各拉丹冬地区位于唐古拉山北部。大地构造位置属东特提斯构造域北部,居拉竹龙—金沙江板块结合带与班公湖—怒江板块结合带之间的羌塘地块,北与可可西里盆地相接。在各拉丹冬西部赤布张错周缘分布有大面积的时代有争议的暗红色砂、砾岩地层。笔者在开展1:25万赤布张错幅野外  相似文献   

5.
长江源各拉丹冬一带发现Gallowayinella Ting类动物群   总被引:1,自引:1,他引:1  
牛志军  曾波夫 《地质通报》2002,21(11):756-758
在1:25万赤布张错幅区域地质调查中,于原划下二叠统开心岭石灰岩组中发现晚二叠世长头期Gallowayinella Ting类动物群化石,表明该区二叠纪地层非属早二叠世,而似应与青海省南部晚二叠世鸟丽群对比。  相似文献   

6.
引起长江源区植被退化和水土流失的主要地质作用浅析   总被引:5,自引:1,他引:5  
通过1:25万赤布张错幅地质调查,发现长江源区植被退化和水土流失极为严重,对造成这一环境的主要地质因素:青藏高原隆升、冰川退缩和冻融作用一一进行了分析,并对其环境演化趋势进行了探讨,指出改善长江源环境的关键是加强保护及生态重建。  相似文献   

7.
在开展藏北多巴区幅1:25万区域地质调查时,在申扎地区永珠-雄梅-果芒错一带发现了一套沿永珠蛇绿岩带(?)分布,岩性特征及成因环境较为特殊的晚侏罗世-早白垩世地层,建立了日拉组及日拉组索尔碎屑岩单位。  相似文献   

8.
李晓勇  谢国刚等 《地质通报》2002,21(11):723-727
通过1:250000邦多区幅和措麦区幅区域地质调查,对西藏文部-姆错丙尼地区的早二叠世拉嘎组进行了地层古生物及杂砾岩特征的研究,发现赋存于滑塌块体中的生物化石反映的地质时期为早二叠世Sakmarian-Artinskian期,而滑塌块体的“基质”地层时代应稍晚于早二叠世Sakmarian-Artinskian期;沉积特征表明杂砾岩成因具冰海相和水下块体重力流的复合(双重)性质。  相似文献   

9.
本文通过1:25万《邦多区幅》和《措麦区福》区域地质调查,对西藏当雄错-姆错丙尼地区的早二叠世拉嘎组进行了地层生物及杂砾岩特征的研究,认为:所采生物化石均赋存于滑塌块体中,反映的地质时期为早二叠世Sakmarian-Artinskian期,而赋含滑塌块体的“基质”地层时代应稍晚于早二叠世Sakmarian-Artinskian期;沉积特征表明杂砾岩成因具冰海相和水下块体重力流的双重(复合)性质。  相似文献   

10.
《沉积与特提斯地质》2005,25(4):111-112
第25卷第1-2期青藏高原南部空白区暨川渝滇黔地区地质调查成果专辑“青藏高原南部空白区暨川渝滇黔地区地质调查成果专辑”序……………………………………丁俊(1)“青藏高原南部空白区基础地质调查与研究”计划项目新成果、新进展……………成都地质矿产研究所(2)1∶25万松西幅、温泉幅地质调查成果与进展…………………………………………安徽省地质调查院(9)1∶25万土则岗日幅、托和平错幅地质调查成果与进展………………………………山西省地质调查院(16)1∶25万查多岗日幅、布若错幅地质调查成果与进展…………………………广西区域地…  相似文献   

11.
This paper reports the first results of a study of 11 isotope systems (3He/4He, 40Ar/36Ar, 34S/32S, 65Cu/63Cu, 62Ni/60Ni, 87Sr/86Sr, 143Nd/144Nd, 206–208Pb/204Pb, Hf–Nd, U–Pb, and Re–Os) in the rocks and ores of the Cu–Ni–PGE deposits of the Norilsk ore district. Almost all the results were obtained at the Center of Isotopic Research of the Karpinskii All-Russia Research Institute of Geology. The use of a number of independent genetic isotopic signatures and comprehensive isotopic knowledge provided a methodic basis for the interpretation of approximately 5000 isotopic analyses of various elements. The presence of materials from two sources, crust and mantle, was detected in the composition of the rocks and ores. The contribution of the crustal source is especially significant in the paleofluids (gas–liquid microinclusions) of the ore-forming medium. Crustal solutions were probably a transport medium during ore formation. Air argon is dominant in the ores, which indicates a connection between the paleofluids and the atmosphere. This suggests intense groundwater circulation during the crystallization of ore minerals. The age of the rocks and ores of the Norilsk deposits was determined. The stage of orebody formation is restricted to a narrow age interval of 250 ± 10 Ma. An isotopic criterion was proposed for the ore-bearing potential of mafic intrusions in the Norilsk–Taimyr region. It includes several interrelated isotopic ratios of various elements: He, Ar, S, and others.  相似文献   

12.
最新的流行病学研究表明,空气中较高浓度的悬浮细颗粒可能对人类的健康有不利的影响。根据该项研究显示,由于心脏病、慢性呼吸问题和肺功能指标恶化而导致死亡率的升高与细尘粒子有关。这些研究结果已经促使欧盟于1999年4月出台了限制空气中二氧化硫、二氧化氮、氧化氮、铅和颗粒物含量的法案(1999/30/EC),对各项指标包括对可吸入PM10颗粒的浓度提出了新的限制性指标。PM10颗粒是指可以通过预分级器分离采集的气体动力学直径小于10μm的细颗粒。目前研究的兴趣重点逐步偏向PM2.5这些更细微颗粒物,PM2.5这种颗粒物对健康有明显的不利影响。在欧盟指令2008/50/EC中,对PM10和PM2.5都提  相似文献   

13.
Komatiites are mantle-derived ultramafic volcanic rocks. Komatiites have been discovered in several States of India, notably in Karnataka. Studies on the distribution of trace-elements in the komatiites of India are very few. This paper proposes a simple, accurate, precise, rapid, and non-destructive wavelength-dispersive x-ray fluorescence (WDXRF) spectrometric technique for determining Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th in komatiites, and discusses the accuracy, precision, limits of detection, x-ray spectral-line interferences, inter-element effects, speed, advantages, and limitations of the technique. The accuracy of the technique is excellent (within 3%) for Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Zr, Nb, Ba, Pb, and Th and very good (within 4%) for Y. The precision is also excellent (within 3%) for Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th. The limits of detection are: 1 ppm for Sc and V; 2 ppm for Cr, Co, and Ni; 3 ppm for Cu, Zn, Rb, and Sr; 4 ppm for Y and Zr; 6 ppm for Nb; 10 ppm for Ba; 13 ppm for Pb; and 14 ppm for Th. The time taken for determining Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th in a batch of 24 samples of komatiites, for a replication of four analyses per sample, by one operator, using a manual WDXRF spectrometer, is only 60 hours.  相似文献   

14.
《Applied Geochemistry》2001,16(2):137-159
Five hundred and ninety-eight samples of terrestrial moss (Hylocomium splendens and Pleurozium schreberi) collected from a 188,000 km2 area of the central Barents region (NE Norway, N Finland, NW Russia) were analysed by ICP-AES and ICP-MS. Analytical results for Al, B, Ba, Ca, K, La, Mg, Mn, Na, P, Rb, Si, Sr, Th, U and Y concentrations are reported here. Graphical methods of data analysis, such as geochemical maps, cumulative frequency diagrams, boxplots and scatterplots, are used to interpret the origin of the patterns for these elements. None of the elements reported here are emitted in significant amounts from the smelting industry on the Kola Peninsula. Despite the conventional view that moss chemistry reflects atmospheric element input, the nature of the underlying mineral substrate (regolith or bedrock) is found to have a considerable influence on moss composition for several elements. This influence of the chemistry of the mineral substrate can take place in a variety of ways. (1) It can be completely natural, reflecting the ability of higher plants to take up elements from deep soil horizons and shed them with litterfall onto the surface. (2) It can result from naturally increased soil dust input where vegetation is scarce due to harsh climatic conditions for instance. Alternatively, substrate influence can be enhanced by human activity, such as open-cast mining, creation of ‘technogenic deserts’, or handling, transport and storage of ore and ore products, all of which magnify the natural elemental flux from bedrock to ground vegetation. Seaspray is another natural process affecting moss composition in the area (Mg, Na), and this is most visible in the Norwegian part of the study area. Presence or absence of some plant species, e.g., lichens, seems to influence moss chemistry. This is shown by the low concentrations of B or K in moss on the Finnish and Norwegian side of the (fenced) border with Russia, contrasting with high concentrations on the other side (intensive reindeer husbandry west of the border has selectively depleted the lichen population).  相似文献   

15.
This paper discusses the result of the detailed investigations carried out on the coal characteristics, including coal petrography and its geochemistry of the Pabedana region. A total of 16 samples were collected from four coal seams d2, d4, d5, and d6 of the Pabedana underground mine which is located in the central part of the Central-East Iranian Microcontinent. These samples were reduced to four samples through composite sampling of each seam and were analyzed for their petrographic, mineralogical, and geochemical compositions. Proximate analysis data of the Pabedana coals indicate no major variations in the moisture, ash, volatile matter, and fixed carbon contents in the coals of different seams. Based on sulfur content, the Pabedana coals may be classified as low-sulfur coals. The low-sulfur contents in the Pabedana coal and relatively low proportion of pyritic sulfur suggest a possible fresh water environment during the deposition of the peat of the Pabedana coal. X-ray diffraction and petrographic analyses indicate the presence of pyrite in coal samples. The Pabedana coals have been classified as a high volatile, bituminous coal in accordance with the vitrinite reflectance values (58.75–74.32 %) and other rank parameters (carbon, calorific value, and volatile matter content). The maceral analysis and reflectance study suggest that the coals in all the four seams are of good quality with low maceral matter association. Mineralogical investigations indicate that the inorganic fraction in the Pabedana coal samples is dominated by carbonates; thus, constituting the major inorganic fraction of the coal samples. Illite, kaolinite, muscovite, quartz, feldspar, apatite, and hematite occur as minor or trace phases. The variation in major elements content is relatively narrow between different coal seams. Elements Sc,, Zr, Ga, Ge, La, As, W, Ce, Sb, Nb, Th, Pb, Se, Tl, Bi, Hg, Re, Li, Zn, Mo, and Ba show varying negative correlation with ash yield. These elements possibly have an organic affinity and may be present as primary biological concentrations either with tissues in living condition and/or through sorption and formation of organometallic compounds.  相似文献   

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The Kuskokwim River at Bethel, Alaska, drains a major mercury-antimony metallogenic province in its upper reaches and tributaries. Bethel (population 4000) is situated on the Kuskokwim floodplain and also draws its water supply from wells located in river-deposited sediment. A boring through overbank and floodplain sediment has provided material to establish a baseline datum for sediment-hosted heavy metals. Mercury (total), arsenic, antimony, and selenium contents were determined; aluminum was also determined and used as normalizing factor. The contents of the heavy metals were relatively constant with depth and do not reflect any potential enrichment from upstream contaminant sources.  相似文献   

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