新疆西昆仑塔什库尔干赞坎铁矿矿床地质特征初探   总被引：2，自引：0，他引：2       下载免费PDF全文

陈勇  吴亮  张春江  崔学敏  李宗成  牛金 《山东国土资源》2013,29(2)

赞坎磁铁矿位于新疆喀什塔什库尔干自治县内,处在塔什库尔干陆块西部,属于沉积变质型热液矿床.区内含矿地层主要为古元古代布伦阔勒群,构造运动和岩浆活动十分发育.矿区内有7个规模较大的磁铁矿体,矿体一般长30~560m,宽6~84m,矿床矿石矿物单一,原生磁铁矿占全铁的5%~94%,矿区有明显的磁异常.可通过地层、磁化率异常,地表黄钾铁矾化、褐铁矿化的方法来寻找新的磁铁矿.  相似文献   

汶川8级地震前的空间电离层异常现象     

张学民  申旭辉  蔡晋安  欧阳新艳  黄建平  刘静  赵庶凡 《国际地震动态》2008,(11)

基于四川汶川8级地震前震中上空DEMETER卫星记录VLF电场频谱数据,利用重访轨道分析了固定纬度点记录的VLF电场信号的背景频谱变化,发现每年的1～6月各频谱变化比较稳定,人工源VLF信号与其他频谱值的幅度相比也清晰可辨,但7～10月扰动比较剧烈,存在整体抬升上升或者快速下降现象,而且人工源VLF信号比较模糊,难以识别.  相似文献   

扇三角洲沉积模式探讨:以准噶尔盆地玛北地区下三叠统百口泉组为例^*   总被引：1，自引：1，他引：0       下载免费PDF全文

彭飚  金振奎  朱小二  崔学敏  杨天博  石良 《古地理学报》2017,19(2):315-326

扇三角洲是一类非常重要的油气聚集场所,准确可靠的扇三角洲沉积模式,对储集层预测具有重要意义。准噶尔盆地玛北地区三叠系百口泉组发育一套扇三角洲沉积体系,虽然前人做了大量的研究,但在沉积模式方面仍存在一些争议。通过现代沉积考察、前人水槽模拟实验、研究区测井、岩心等资料综合分析发现: (1)玛北地区百口泉组扇三角洲平原发育3类微相,即辫状河道微相、砾质漫滩微相、水上朵前泥微相,同时可见泥石流沉积;玛北地区百口泉组扇三角洲前缘发育2种微相,即砾质浅滩微相、砂质浅滩微相,同时可见碎屑流沉积;(2)扇三角洲平原河道与河道间均为砂砾岩,河道砂砾岩的分选性明显好于河道间砂砾岩;(3)扇三角洲前缘不发育水下分流河道,扇三角洲前缘的砂砾岩主体是由扇三角洲平原片流入湖形成的,呈席状。  相似文献   

Mesoscale experimental study on chemical composition,pore size distribution,and permeability of tailings     

Zengguang Xu  Yang Yang  Junrui Chai  Xuemin Yang  Yuan Qin  Yanlong Li 《Environmental Earth Sciences》2017,76(20):707

To study the seepage characteristics of tailing sand, an indoor sand column test was performed with three kinds of tailing sand obtained from Henan and Shaanxi provinces, China. River sand, quartz sand, and glass beads were also employed for comparison. Using the nuclear magnetic resonance, the researchers studied pore size distribution and permeability under different hydraulic gradients. The chemical composition and particle morphology were analyzed by energy-dispersive spectrometry and X-ray diffraction. The results were as follows. (1) The three kinds of tailings sand are small in diameter, mainly in the range from 0.15 to 0.5 mm. Their diameter distribution is more concentrated than river sand. The surface of tailing sand is rough. As for chemical composition, tailing sand contains many kinds of metal elements. (2) With hydraulic gradient increasing, the micropores in the tailings samples become fewer, the larger pores grow in number, and the peak of the pore size distribution changes to the left; blocking is more obvious. (3) The small pores gradually decrease during the test. Under the influence of groundwater pressure, the smaller gravel could migrate and block tiny pores. The structure of particle arrangement becomes denser. Therefore, it would prevent the seepage liquid from passing through the medium. The permeability coefficient K decreases.  相似文献   

Geochemical and Hf isotopic compositions of Late Triassic–Early Jurassic intrusions of the Erguna Block,Northeast China: petrogenesis and tectonic implications     

Jun Gou  Yun-Sheng Ren  Xue-Gang Hou  Dong-Guang Yang 《International Geology Review》2017,59(3):347-367

Late Triassic–Early Jurassic intrusions of the Erguna Block, Northeast China, are located along the southern margin of the Mongol–Okhotsk orogenic belt. They comprise granodiorite, monzogranite, syenogranite, and lesser gabbro–diorite, of adakitic and calc­alkaline affinity. The adakite-like and calc­alkaline granites share similar light rare earth elements (LREE) characteristics; however, their heavy rare earth elements (HREE) trends differ from one another. The relative abundances of HREE in the calc­alkaline granites are relatively consistent and are similar to those of intrusive rocks formed from dehydration melting of garnet-free amphibolitic source rocks at relatively low pressures. In contrast, the adakite-like granites show more prominent HREE fractionation trends, indicating that they crystallized at higher pressures, where garnet in the source rocks was stable. At least two isotopically distinct sources were involved in the petrogenesis of the granites, but the extent to which they contributed varies between plutons. Most intrusions have incorporated an isotopically primitive component, possibly juvenile mafic crust. The other sources include a small proportion of old continental crustal material and isotopically evolved wall rocks. The gabbro–diorites have high MgO contents (>7 wt.%), a high Mg^# (>0.6), and show moderate LREE and HREE fractionation, indicating they formed from the melting of subducted metasomatized lithospheric mantle. All of the intrusions in the study area are characterized by a relative enrichment in large ion lithophile elements (LILE) and depletion in high field strength elements (HFSE), indicating they were emplaced in an Andean-type active continental margin setting related to southward subduction of the Mongol–Okhotsk oceanic plate.  相似文献   

China's hydropower potential and its utilization     

Cheng Xuemin  Zhu Chengchang 《GeoJournal》1985,10(2):141-149

According to a recent survey, the total exploitable hydropower potential in China amounts to 378,000 MW, corresponding to 1,923 TWh of annual generation.The role of hydro energy in China's energy structure is evaluated. A complete account of the historical growth as well as the geographical distribution of hydropower utilization in China is compiled. Small hydropower in China, a topic of world interest, is also concisely described.  相似文献   

Jianganlin Surface Rupture of Lushan Ms7.0 Earthquake, Sichuan, China     

LIU Mingjun  WANG Fuyun  JIA Shixu  HAN Yanjie  LI Xuemin  FENG Jianlin  SUN Hong  XIN Hailiang  ZHANG Jianshi  TAO Hong  DAI Aopeng  SUN Yin  WANG chong 《《地质学报》英文版》2013,87(Z1):367-367

  相似文献   

甘肃南部公元1824年以来降水重建   总被引：1，自引：0，他引：1  

刘昶智  勾晓华  方克艳  刘文火  曹宗英  赵志千 《第四纪研究》2013,33(3)

通过对甘肃南部腊子口的油松(Pinus tabulaeformis)进行树木年轮分析,首次建立了研究区1824～ 2011年标准化年表(STD),并与邻近的岷县气象站降水和温度进行相关分析,结果表明,该年表与上一年8月到当年7月的总降水(p8 c7)相关性最好,相关系数达到0.644 (p＜0.01).据此建立树轮指数与降水量之间的转换方程,该方程解释了实测期41.5％的降水(1952 ～2008年),并通过一系列稳定性检验,进而重建研究区1824～ 2011年间188年以来的降水.对重建结果进行11年滑动平均,结果表明,共出现3次极干旱期,分别为1900 ～1902年,1926～1930年和1997 ～2000年,尤以1997～ 2000年最为严重,极干旱期占到重建期的6.38％,而极湿润期只有1937年,仅占0.53％.与邻近区已有的研究对比后发现,1920s～ 1930s干旱事件在研究区以北区域更为严重.重建结果与赤道东太平洋、中太平洋平均海表温度(SST)呈显著负相关(p＜0.1),说明研究区干旱变化与海温存在遥相关关系;多窗谱分析(MTM)结果表明降水存在2～3年和7年周期.ENSO事件时,东亚季风减弱,位于季风边缘区的甘肃南部地区出现干旱化趋势.  相似文献   

大柏舍地电台映震能力初析   总被引：2，自引：0，他引：2  

王志贤  彭远黔 《东北地震研究》1997,13(1):25-30

分析了大柏舍地电台１８年的有效观测资料，研究了ρｓ异常变化与周围一定范围内发生的Ｍｓ≥４．０级地震的对应关系，评价了该台的映震能力，结果表明，在所发生的１３次Ｍｓ≥４．０级地震中，有１０次地震前观测到了明显的ρｓ异常变化，其中Ｍｓ≥４．３级地震，都有ρｓ前兆反应，５次５级以上地震尤为显著，表明该台具有较强的映震能力。  相似文献   

融合地震属性和成像测井信息优化的储层缝洞带评价与钻井轨迹     

王磊  沈金松  邹榕  蔺学敏  徐忠祥  苏朝阳  杨萍 《吉林大学学报(地球科学版)》2021,51(2):607-623

针对新疆某工区强非均质性岩溶缝洞型碳酸盐岩储层,提出了一种基于地震多属性优化与电成像测井信息融合的碳酸盐岩储层缝洞带识别评价与钻井轨迹优化设计方法。首先,利用相干体、蚂蚁体等多种地震属性与张量约束的稀疏脉冲反演结果综合实现缝洞发育带空间分布预测与雕刻,确定可能油气圈闭的分布范围;然后,基于数学形态学滤波方法,由电成像测井资料自动拾取井壁的裂缝和溶蚀孔洞分布,统计井壁裂缝倾向和倾角;再次,用工区内钻孔多臂井径资料计算的井筒崩落信息与电成像资料拾取的诱导缝信息预测工区的最大和最小主应力方向;最后,融合地震属性与电成像测井信息评价的缝洞分布结果,预测工区内走滑断裂带的最大主应力方向以NE—SW为主,局部为NW—SE,且以中高角度为主的裂缝走向与主应力近乎平行。采用预测主应力分布方法实现了沿NW—SE方向的大斜度井与水平井优化设计,钻遇了大规模优质储集体,获得了稳定油流,并以此为基础在周围打井若干口,极大地降低了深层勘探的钻井风险。  相似文献