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81.
介绍了信宜1、2号井水文地质环境,总结了近年来两井水温的同震响应现象,并对其机理进行了初步的探讨。认为两口井的同震响应虽然形态不一致,但机理是相近的,主要是由于地震波的扰动,随着振动效应的作用,加大了不同含水层间的垂直运动速率,而产生水温上升或下降现象,震后一段时间随着混合通道的闭合或运动速率的恢复,2号井的水温逐渐恢复到原有的水平上。 相似文献
82.
Conventional diamond exploration seldom searches directly for diamonds in rock and soil samples. Instead, it focuses on the search for indicator minerals like chrome spinel, which can be used to evaluate diamond potential. Chrome spinels are preserved as pristine minerals in the early Paleozoic (∼465 Ma), hydrothermally altered, Group I No. 30 pipe kimberlite that intruded the Neoproterozoic Qingbaikou strata in Wafangdian, North China Craton (NCC). The characteristics of the chrome spinels were investigated by petrographic observation (BSE imaging), quantitative chemical analysis (EPMA), and Raman spectral analysis. The results show that the chrome spinels are mostly sub-rounded with extremely few grains being subhedral, and these spinels are macrocrystic, more than 500 µm in size. The chrome spinels also have compositional zones: the cores are classified as magnesiochromite as they have distinctly chromium-rich (Cr2O3 up to 66.56 wt%) and titanium-poor (TiO2 < 1 wt%) compositions; and the rims are classified as magnetite as they have chromium-poor and iron-rich composition. In the cores of chrome spinels, compositional variations are controlled by Al3+-Cr3+ isomorphism, which results in a strong Raman spectra peak (A1g mode) varying from 690 cm−1 to 702.9 cm−1. In the rims of chrome spinel, compositional variations result in the A1g peak varying from 660 cm−1 to 672 cm−1. The morphology and chemical compositions indicate that the chrome spinels are mantle xenocrysts. The cores of the spinel are remnants of primary mantle xenocrysts that have been resorbed, and the rims were formed during kimberlite magmatism. The compositions of the cores are used to evaluate the diamond potential of this kimberlite through comparison with the compositions of chrome spinels from the Changmazhuang and No. 50 pipe kimberlites in the NCC. In MgO, Al2O3 and TiO2 versus Cr2O3 plots, the chrome spinels from the Changmazhuang and No. 50 pipe kimberlites are mostly located in the diamond stability field. However, only a small proportion of chrome spinels from No. 30 pipe kimberlite have same behavior, which indicates that the diamond potential of the former two kimberlites is greater than that of the No. 30 pipe kimberlite. This is also supported by compositional zones in the spinel grains: there is with an increase in Fe3+ in the rims, which suggests that the chrome spinels experienced highly oxidizing conditions. Oxidizing conditions may have been imparted by fluids/melts that have a great influence on diamond destruction. Here, we suggest that chrome spinel compositions can be a useful tool for identifying the target for diamond potential in the North China Craton. 相似文献
83.
The Xingdi mafic-ultramafic intrusions occur in the northeastern margin of the Tarim craton. The Xingdi No. 3 intrusion is the smallest of four intrusions, with an exposed area of 1.7 km~2, and the zircon U-Pb age of the intrusion is 752±4 Ma. The intrusion consists of gabbros, pyroxenites and peridotites, and exhibits a crystallization sequence of the main rock-forming minerals as olivine, orthopyroxene, clinopyroxene and plagioclase. Mineralization occurred at or near the boundaries of the intrusion between pyroxenites and peridotites, and appears as a layered or lenticular shape about 500 m long and 4–15 m wide. The primary sulfides have a relatively simple mineralogy dominated by pyrrhotite-pentlandite-chalcopyrite assemblages, which occur as droplet, star-like and graphic texture and locally sideronitic structures. Geochronological and geochemistry investigations suggest that the Xingdi mafic-ultramafic intrusions and coeval volcanic rock in the Kuluktag area of the Tarim craton formed in an intracontinental breakup environment. Based on the composition of the dominant rockforming minerals and covariant relationships of other oxides versus Mg O, the parental magma of the Xingdi No.3 intrusion belongs to high-Mg tholeiitic basaltic magmas with Mg O of 10.78 wt%. The Xingdi No.3 intrusive rocks are characterized by light REE enrichment relative to heavy REE, negative Nb-Ta anomalies, low ~(143)Nd/~(144)Nd ratios(from 0.511183 to 0.511793) and high initial ~(87)Sr/~(86)Sr ratios(from 0.7051 to 0.7113). The magma was derived from the enriched-lithospheric mantle and was contaminated during emplacement. According to rock assemblages, mineralization, olivine characteristics, geochemical characteristics and mass balance, there are better copper-nickel ore prospects in the Xingdi No.3 intrusion than in the other three intrusions in the area. 相似文献
84.
乌拉特中旗284东矿区已开展金矿勘查工作多年,但一直未取得较大进展。以往勘查工作认为矿体赋存于破碎蚀变的石英闪长岩中,但矿床规模不大。在对以往地质资料进行分析总结和实地踏勘工作的基础上,提出了区内炭质千糜岩为主要赋矿岩石的找矿新思路,并通过对以往施工钻孔岩心的重新编录和取样分析以及坑道施工,对找矿思路进行了实践。通过地质工作,在炭质千糜岩中发现了金矿体,矿体规模达500 m(走向)×500 m(斜深),为找矿思路提供了强有力的成果支持。新发现的金矿体位于(1)号蚀变带内,受F9断裂控制;矿体存在SW向侧伏规律,在构造交汇及产状变化等部位易形成厚大矿体;矿石具有贫金属硫化物、易见明金的特点,金粒径变化范围较大。依据新思路进行下步找矿工作有望取得较大找矿突破,增加金资源量。找矿新思路的提出不仅为该区金矿勘查指明了方向,也为相邻矿区金矿勘查工作提供了新的启示。 相似文献
85.
基于天山托木尔峰青冰滩72号冰川2008年高精度差分GPS测量资料,2009年末端重复测量数据以及1964年地形图,通过对比研究近45 a来该冰川的变化特征,结果表明:1964~2009年,青冰滩72号冰川末端退缩1 852 m,年均后退41 m,由此造成面积减少约为1.53 km2,年均减少0.03 km2;1964~2008年,冰舌平均减薄9.59±6 m,年均减薄约0.22±0.14 m,冰储量亏损达14.1±8.8×10-3 km3(12.7±7.9×10-3 km3 w.e.)。与天山其它区域典型监测冰川相比,青冰滩72号冰川消融强烈,是区域气候、末端海拔、冰川类型、表碛覆盖等因素综合影响的结果。 相似文献
86.
87.
Chemical characteristics and environmental significance of fresh snow deposition on Urumqi Glacier No. 1 of Tianshan Mountains, China 总被引:2,自引:0,他引:2
Ice and snow chemistry of alpine glaciers is crucial for the research of regional atmospheric environment change. Fresh snow samples were weekly collected from Urumqi Glacier No.1 in the Tianshan Mountains, Xin- jiang, China, and the chemical characteristics and seasonal variations of major ions, mineral dust, δ18O and trace metals were measured. Results show that the concentrations of major ions in the snow are Ca2+ SO42- NH4+ NO3- Cl- Na+ Mg2+ K+, in which Ca2+ is the dominant cation, and SO42-is the dominant anion. All major ions have close positive correlations with each other except NO3-. δ18O shows positive correlation with air temperature change during the study period. Mineral dust particle and major ionic concentrations in fresh snow have obvious seasonal change, with high concentration in spring but low concentration in summer and autumn, which indicates that the chemical mass input from Asian dust activity to snow is very significant. Temporal changes of trace metals in fresh snow, e.g., Cd, Pb, Zn, Al, Fe, have shown that human-induced pollution of central Asian region also has large contribution to the snow chemistry on alpine glaciers of the Tianshan Mountains. 相似文献
88.
乌兰诺尔井田位于内蒙古自治区东北部,含煤地层主要为白垩系下统巴彦花组,6号煤是区内唯一可采煤层,其显微组分镜质组含量为85.2%~91.0%,惰质组含量为2.0%~13.4%,壳质组在2%以下。测试分析表明6号煤属中灰、低—中高硫、高热值褐煤,其挥发分高,化学反应性好,燃烧时速度快,反应充分,是很好的动力燃料,适用于火力发电。 相似文献
89.
Re、Se是中国急需的紧缺矿种,对国家的资源战略与环境安全保障具有重要影响。新疆伊犁盆地511矿床在开采铀的过程中,发现了Re、Se和Mo等元素存在富集的现象。文章以511矿床7号采区为例,采取野外地质调查与室内分析测试及综合研究相结合的技术路线,以探求Re、Se、Mo等元素的分布特点及其与U元素富集之间的关系。研究表明,Re和Se在空间上与砂岩铀矿体密切共生,说明在511矿床中矿源等条件具备的情况下,7号采区内的层间氧化作用促使Re和Se富集成矿,证实了511铀矿床中与U密切相关的Se、Re等元素具有线状分布的特点。 相似文献
90.
新集二矿的主采煤层位于山西组的底部,受到下伏太原组岩溶裂隙含水层的威胁。为缓解井下的防治水压力.采用了在地面施工排水孔的防治水思路。根据钻孔的位置及地层情况,采用了泥浆循环钻进与空气潜孔锤钻进相结合的方法。由于在钻孔施工过程中,发生了泥浆向巷道渗漏的情况,为保证钻孔施工安全及井下生产安全而对钻孔设计深度进行了调整,从而顺利的完成了该孔的钻探施工任务。此孔的成功,可为类似地区施工矿井防治水钻探工程提供借鉴。 相似文献