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通 过 钱家 营井 田 203泥石 流 突发 事故 ,对 陷落 柱 的形 成机 理 作进 一步 的 研究 ,巷 道临 空 空间 、构 造破 碎带 、高压 地下 水 的存 在是 煤 系砂 岩地 层 中形 成现 代 陷落 柱的 主 要控 制因 素 。 相似文献
63.
塔里木盆地北缘库车盆地白垩系风成砂岩研究--以库车河剖面为例 总被引:2,自引:0,他引:2
库车盆地的早白垩世地层为一套干旱气候条件下的红层沉积,包括洪积扇砾岩、间歇性河流砂砾岩、风成细砂岩和粉砂岩、沙漠湖相紫红色泥岩等类型的沉积,组成一个较为典型的沙漠沉积体系。在库车河剖面,下白垩统红层中发育一些厚层至块状的“高能细砂岩和高能粉砂岩”,多为岩屑长石石英砂岩和长石岩屑石英砂岩。它们以良好的分选性和较高的结构成熟度、较细的粒度、较低的成分成熟度和大型交错层理的发育为特征,显示出较为明显的风成沉积特点。 相似文献
64.
Distribution characteristics and petroleum geological significance of the Silurian asphaltic sandstones in Tarim Basin 总被引:1,自引:0,他引:1
The Tarim Basin is a typical superimposed basin in which there have occurred multiphase adjustment and destruction of the reservoirs. The widely distributed asphaltic sandstones of the Silurian are the very product after destruction of the reservoirs. Studies show that the Silurian asphaltic sandstones distributed in both the middle and western parts on the basin are controlled chiefly by the Caledonian oil source area and by the Tazhong, Tabei and Bachu uplifts, whereas the distribution of the asphaltic sandstones on local structural belts is controlled by the reservoir's sedimentary system. Vertically, most of the asphaltic sandstones are under the regional caprock of red mudstones and the upper sandstone section of compact lithology. Due to the difference of hydrocarbon destruction in the early stage and the influence of hydrocarbon recharge in the late stage, the asphaltic sandstones and oil-bearing sandstones in the Tazhong area can be vertically divided into the upper and lower sections and they have an interactive distribution relationship as well. Asphaltic sandstones exist not only in intergranular pores but also inside the grains of sand and between the crevices, proving the destruction of early reservoirs due to uplifting. The existence of asphaltic sandstones over a large area reveals that the large-scale migration and accumulation and the subsequent destruction of hydrocarbons in the Craton area. The destruction caused a loss of the reserve resources of the Palaeozoic amounting to nearly 13.3 billion tons. Asphaltic sandstones formed after the destruction of oil and gas may serve as an effective caprock which is beneficial to accumulation of hydrocarbons and formation of the pool sealed by asphaltic sandstones in the later stage. The destruction of the early Silurian hydrocarbons depends on the stratigraphic burial depth. The deep part under the northern slope of Tazhong is an area favorable to search of undestroyed Silurian oil reservoirs. 相似文献
65.
Development characteristics of interlayer oxidation zone type of sandstone uranium deposits in the southwestern Turfan-Hami basin 总被引:3,自引:0,他引:3
YANG Dianzhong XIA Bin & WU Guogan Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou China 《中国科学D辑(英文版)》2004,47(5)
The known uranium ore and anomaly occur-rences are distributed mainly in the southwestern part of the Turfan-Hami basin. The focus of current explo-ration is placed on the leachable interlayered oxidation zone type of sandstone uranium deposits. Uranium deposits in the sedimentary basin can be classified into three types in accordance with their host rock types, i.e. the sandstone-type uranium deposits, the coal rock-type uranium deposits and the mud-stone-type uranium deposits. The sandstone… 相似文献
66.
小秦岭金矿含金石英脉中黄铁矿晶体的表面微形貌研究 总被引:1,自引:0,他引:1
利用微分干涉显微镜、扫描电镜、透射电镜等对小秦岭金矿含金石英脉中黄铁矿晶体的表面微形貌进行了研究。黄铁矿晶体的{210}面上发育自由生长层,表明{210}面是F面,其生长机理受二维成核层生长所制约。除简单的五角十二面体外,其他形态黄铁矿晶体的{210}面上也发育有自由生长层。{210}面上的正条纹有些是由{100}面上生长层的边缘台阶在{210}面上叠堆形成,另一些正条纹则是{210}面上生长层边缘台阶堆叠的产物。透射电镜和电子衍射花样研究表明,负条纹黄铁矿晶体是由30~50nm大小的核团经自动定向附生作用形成,每个核团不是单晶体,而是由许多早先在溶液中形成的小微晶聚合而成。这些特征表明负条纹黄铁矿晶体是在溶液过饱和度极高和温度梯度小的理想环境中形成,它的形成与杂质无关。PBC理论和唐纳-哈克定律能较好地解释自然界中黄铁矿晶体{100}面上普遍发育自由生长层、而{210}面上自由生长层极为罕见的原因。除日本释迦内矿区黑矿之上的浮岩凝灰岩中产生出负条纹黄铁矿晶体外,在石英脉型金矿床中也有负条纹黄铁矿晶体产出。 相似文献
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69.
Weathering: Toward a Fractal Quantifying 总被引:1,自引:0,他引:1
Klaudia Oleschko Jean-Francois Parrot Gerardo Ronquillo Sergey Shoba Georges Stoops Vera Marcelino 《Mathematical Geology》2004,36(5):607-627
Weathering occurs over a wide range of scales. To link features through these scales is a major challenge for interdisciplinary weathering studies. Fractal approach seems to be specially useful for this purpose. We introduce a multistep fractal weathering assessment scheme devoted to extract fractal weathering classifiers from texture analysis of the mineral's image. Our scheme enables to quantitatively estimate the global and local information about the geometry of the weathering pattern. This information is basic to develop geometrical indices of weathering, which can significantly enrich the common qualitative and semiquantitative weathering assessment schemes. To justify the fractal approach, a strong statistical self-similarity has been documented for both the weathering and fresh features of two common silica minerals: quartz and biogenic A-opal (phytolith) over four orders of length scales. The procedure is fast, drastically reduces thresholding bias, promises to be universal, it is valid for genetically different minerals and rock types, scale independent, and specially useful for monitoring the changes in the mineral's roughness during the alteration. Two of the proposed classifiers seem to be potentially useful for direct application in the field and be used by nonspecialist. 相似文献
70.
Information about the magmatic to hydrothermal transition is preserved in late-stage features of quartz phenocrysts and endoskarn alteration in some Cu–Zn skarn deposits such as the Empire Mine in Idaho. Important features include: (1) quartz phenocrysts with strong resorption textures such as vermicular zones of igneous groundmass cutting primary quartz cathodoluminescence banding, (2) anomalous amounts of endoskarn (more than 50% of mineralized rock), (3) high F activities as evidenced by fluorite as an accessory mineral in igneous rocks, in alteration assemblages, and in fluid inclusions and by high F in hydroxyl sites in igneous biotite and amphibole, and (4) direct association of Zn, which normally is deposited distally at low temperature, with Cu in proximal locations and in endoskarn. These features are explained by the following model: (1) F lowers the solidus temperature of the magma, thus changing the timing, temperature, and duration of hydrothermal fluid exsolution. (2) Upon magmatic vapor saturation the F-rich hydrothermal fluids form bubbles that adhere to quartz phenocrysts and chemically corrode/tunnel into the quartz forming vermicular resorption textures. (3) F-rich hydrothermal fluids also promote the formation of endoskarn; silicic rocks are attacked by F-rich fluids in the same sense that carbonate wall rocks are dissolved by weakly to moderately acidic hydrothermal fluids. (4) Low fluid exsolution temperature facilitated by high F activity promotes high Zn/Cu ratios in proximal locations due to the solubility of Zn relative to Cu at lower temperatures. This model may be applicable at other localities such as the world-class Cu–Zn skarn Antamina mine, as well as some tin and rapakivi granites. 相似文献