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新疆东准噶尔卡拉麦里地区早泥盆世火山岩由玄武岩和玄武安山岩组成,采用LA-ICP-MS锆石U-Pb定年方法,获得玄武安山岩锆石的U-Pb年龄为404.5±1.9 Ma,表明喷发时代为早泥盆世。岩石地球化学显示早泥盆世火山岩属岛弧拉斑系列,具相对较高的Mg# 值(41.25～55.32)及较低的Nb(1.11×10- 6～2.42×10- 6)、Zr(73.9×10- 6～95×10- 6)和ΣREE(81.50×10- 6～121.80×10-6)含量。富集大离子亲石元素(LILE：K、Rb、Ba)和轻稀土元素(LREE),而亏损Ta、Nb和Ti高场强元素（HFSE：Ta、Nb、Ti）,并显示Eu弱的亏损,这些特征与岛弧火山岩类似,其原始岩浆可能起源于俯冲流体交代的亏损地幔楔的部分熔融。结合区域地质背景,认为早泥盆世火山形成于洋内弧的构造环境,为卡拉麦里古洋盆向北俯冲消减的产物。这是在卡拉麦里地区首次报道的洋内弧火山岩,这一新的发现和认识对研究东准噶尔古生代洋盆演化及区域构造格局均具有重要的意义。 相似文献
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罗布泊是世界最大干盐湖之一,罗布泊超大型钾盐矿床从1995年发现至今,经历了找钾远景预测、勘查、系统科学研究、扩大找矿及开发利用快速推进的过程,浅部(200m以浅)钾盐资源量已基本查明,但没有一个穿透第四系的较深地质科学钻井。通过区域气候条件、盐类矿物分布、碎屑岩层储卤等方面与柴达木盆地西部的对比分析以及罗布泊地堑式断陷带储卤的发现,提出罗布泊深部具有钾盐成矿远景。在罗布泊罗北凹地西北部实施盐湖深部钾盐找矿第一深井(LDK01井),首次发现钾芒硝、钾锶矾、红钾铁盐等盐类矿物;在深部地层碎屑岩层中发现钾盐矿物钾石盐、光卤石等,地层中KCl含量高达2.86%,揭示地层深部存在低品位固体钾矿,确定为一种新类型钾矿,即碎屑岩型钾矿,为罗布泊深部钾盐找矿拓展了方向和空间;深层碎屑岩地层储集卤水,卤水KCl平均品位1.50%,揭示出罗布泊盐湖深部存在富钾卤水。重力探测发现罗布泊盆地西部发育次级凹地,初步确定凹地中心第四系沉积厚度大于1200m。结合地质分析,预测库鲁克塔格山前断陷盆地和罗北盆地为进一步寻找深部隐伏钾盐矿床的重要靶区。综合遥感、物探、物性特征等资料及研究成果,估算罗北凹地深部钾盐预测资源量为1.60×108t,并提出罗北凹地西部及附近区域的深部地层中还蕴藏有丰富的钾盐资源,罗布泊深部找钾潜力巨大。该成果对深化认识罗布泊盐湖的形成演化及满足钾肥生产企业大规模开发均具有重要意义。 相似文献
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苏盖特构造带位于新疆昆仑山弧形推覆体前缘.本文通过研究苏盖特构造带的构造特征,确定了地震反射层的地质属性,认为苏盖特构造带由表层推覆体及下部下第三系-二叠系之间的地层经过3次重复形成的叠瓦状推覆体构成.苏盖特构造带活动始于上新世阿图什组沉积期,定型于更新世.通过研究西昆仑逆冲推覆体及已钻探井的地表油源、储层特征及储盖组合,认为苏盖特构造带具有两套好的油源即石炭-二叠系及侏罗系油源,两套好的储集层即白垩系和下第三系储层,相应地,发育两套储盖组合,具有良好的圈闭及运聚条件,是有利的勘探目标区. 相似文献
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YAN Xinlu ZHANG Songhang TANG Shuheng LI Zhongcheng WANG Kaifeng YI Yongxiang DANG Feng HU Qiuping 《《地质学报》英文版》2019,93(3):692-703
The main methods of coalbed methane(CBM) development are drainage and depressurization, and a precise prediction of coal reservoir pressure is thus crucial for the evaluation of reservoir potentials and the formulation of reasonable development plans. This work established a new reservoir pressure prediction model based on the material balance equation(MBE) of coal reservoir, which considers the self-regulating effects of coal reservoirs and the dynamic change of equivalent drainage area(EDA). According to the proposed model, the reservoir pressure can be predicted based on reservoir condition data and the actual production data of a single well. Compared with traditional reservoir pressure prediction models which regard EDA as a fixed value, the proposed model can better predict the average pressure of reservoirs. Moreover, orthogonal experiments were designed to evaluate the sensitivity of reservoir parameters on the reservoir pressure prediction results of this proposed model. The results show that the saturation of irreducible water is the most sensitive parameter, followed by Langmuir volume and reservoir porosity, and Langmuir pressure is the least sensitive parameter. In addition, the pressure drop of reservoirs is negatively correlated with the saturation of irreducible water and the Langmuir volume, while it is positively correlated with porosity. This work analyzed the reservoir pressure drop characteristics of the CBM wells in the Shizhuangnan Block of the Qinshui Basin, and the results show that the CBM reservoir depressurization can be divided into three types, i.e., rapidly drop type, medium-term stability type, and slowly drop type. The drainage features of wells were reasonably interpreted based on the comprehensive analysis of the reservoir depressurization type; the latter was coupled to the corresponding permeability dynamic change characteristics, eventually proving the applicability of the proposed model. 相似文献
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Xinlu Hu Shuzhen Yao Mouchun He Zhenju Ding Yubao Cui Jun Shen Bin Chen Bopeng Zhu 《Resource Geology》2014,64(2):102-116
The Daheishan porphyry Mo deposit was recently discovered in the northern segment of the Great Xing'an Range, NE China. Three main types of granitoids are identified in this deposit: granodiorite, fine‐grained granite, and porphyritic granite. The orebodies are dominantly hosted within the granodiorite and in the contact zone between the granodiorite and tuff or hornfels, while no mineralization has been found in the fine‐grained granite or the porphyritic granite. We present in situ LA‐ICP‐MS zircon U‐Pb dates for the granodiorite, fine‐grained granite, and porphyritic granite, which yielded 146.9 ± 1.1 Ma (2σ), 146.6 ± 1.7 Ma (2σ), and 149.7 ± 4.2 Ma (2σ), respectively. Their εHf(t) values range from 3.9 to 12.2, associated with young crustal model ages (TDM2) ranging from 524 Ma to 849 Ma, indicating that their parental magmas may have been generated by partial melting of the Neoproterozoic–Cambrian crustal components. The formation of the Daheishan deposit was genetically related to the subduction of the Paleo‐Pacific Plate. 相似文献
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Suofei Xiong Mouchun He Shuzhen Yao Yubao Cui Guanzhong Shi Zhenju Ding Xinlu Hu 《Geological Journal》2015,50(6):720-738
The Chalukou giant Mo deposit in the Heilongjiang Province, northeastern China, is a porphyry deposit hosted in an intermediate‐felsic complex surrounded by Mesozoic volcano–sedimentary rocks. The mineralization process is composed of four stages, including quartz + K‐feldspar (Stage I), quartz + molybdenite (Stage II), pyrite + chalcopyrite + quartz ± other sulphides (Stage III) and carbonate ± fluorite ± quartz (Stage IV). The mineralization is generally associated with intense K‐feldspar‐, fluorite‐, phyllic‐ and propylitic alteration. Primary fluid inclusions (FIs) in quartz include four compositional types, i.e. pure carbonic (PC‐type), aqueous‐carbonic (C‐type), daughter mineral‐bearing (S‐type) and aqueous (W‐type) inclusions. Halite, sylvite and hematite are recognized as the daughter minerals in Stage I S‐type FIs, whereas molybdenite and chalcopyrite occur as daughter minerals in Stage II S‐type FIs. High‐salinity and high pressure (>220 MPa) FIs exist in Stage I quartz veins, characterized by homogenization through halite dissolution at temperatures of 324 to 517 °C. The paucity of coexisting vapour‐rich FIs with similar homogenization temperatures at this stage indicates that the initial S‐type inclusions have directly exsolved from the magma rather than boiling off of a low‐salinity vapour. Stage I quartz has captured the C‐ and W‐type FIs, which have totally homogenized at 270–530 °C with salinities of 1.6–17.0 wt.% NaCl equiv. At Stage II, the coexistence of all FI types were only observed at pressures of 150–218 MPa and temperatures of 352–375 °C, with two salinity clusters of 0.9–16.6 wt.% NaCl equiv. and 37–56 wt.% NaCl equiv. Stage III quartz contains W‐type FIs with homogenization temperatures of 158–365 °C, salinities of 0.5–9.0 wt.% NaCl equiv., and minimum pressures of 12–116 MPa; whilst Stage IV fluorite or calcite only contains W‐type FIs with homogenization temperatures of 121–287 °C, salinities of 0.5–5.3 wt.% NaCl equiv., and minimum pressures of 10–98 MPa. The estimated trapping pressure from Stages II to III suggests an alternating lithostatic–hydrostatic fluid‐system caused by fluid boiling. Ore fluids at the Chalukou Mo deposit may have been evolved from a CO2‐rich, high‐salinity, and high‐oxygen fugacity (fO2) magma system, to a CO2‐poor, low‐salinity, and low‐fO2 epithermal system. Two key points may have contributed to the formation of the Chalukou giant Mo deposit: The magmatic origin and fluid boiling that has resulted in decompression and rapid precipitation of metals. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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Climate Dynamics - Satellite microwave temperature sounding data have been widely used in the study of climate trends over the past decades. When merging advanced microwave sounding unit-A (AMSU-A)... 相似文献
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基于渤海钻井资料和三维地震资料,梳理了渤海海域前新生代基底岩性、地层、结构、构造特征。将渤海基底划分为前寒武系、古生界、中生界三个构造层,论述了各个构造层残余地层分布特征,并将基底结构分为三种类型,单层型、双层型、三层型。基底构造演化表现为“垂直升降→强烈挤压→局部伸展→强烈伸展反转→整体隆升→‘伸展+走滑’复合改造”6大阶段。结合薄片及物性资料探索了基岩储层发育规律,单层型前寒武系变质岩、双层型顶部的碳酸盐岩或火山岩、三层型顶部中生界火山岩为有利的勘探目标。围绕在富烃凹陷周边的潜山,在岩性和供油窗口耦合的情况下,具有良好的勘探前景。 相似文献