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31.
西昆仑地区塔木MVT型铅锌矿床成矿作用和成矿物质来源探讨 总被引:6,自引:0,他引:6
MVT型铅锌矿是西昆仑地区重要的铅锌矿床类型之一.为了探明西昆仑地区该类型矿床的成矿作用过程和成矿物质来源,本文以塔木矿床为例,在野外调研基础上,进行了光片鉴定、铅硫同位素、稀士元素和成矿元素研究,得到矿石中方铅矿的δ34SCDT为-5.04‰~+3.67‰,反映出油田卤水与深层卤水的混合特征;由铅同位素分析结果计算出表面年龄为461~481 Ma(早于泥盆纪438~410 Ma);由稀土元素分析数据得出岩(矿)石/球粒陨石标准化分配模式图表明,成矿物质主要来自地层.因而判定主要成矿物质可能来源于前泥盆系地层.喜马拉雅期逆冲推覆构造作用所引发的大规模热卤水运移、循环过程,导致矿质的进一步富集、沉淀. 相似文献
32.
对甘肃省玉门青6井和平凉泾川泾3井两口深水井的水氡及辅助项目观测资料采用多元逐步回归、相关距平、一阶差分等方法进行处理,分析并排除了主要干扰因素,显示出两井在肃南5.4级、托莱6.0级和礼县5.1级地震前有明显异常,对两井的映震效能和地震预报前景进行了评价。 相似文献
33.
流动成像测井研究进展 总被引:2,自引:3,他引:2
流动成像测井属于对非均匀介质动态的非线性测量,通过对油气井内多相流体信息的投影扫描和反演处理,实时成像显示流体分布及流动状况,国外研制的电导法,电容法仪器采用电导探针或电容元件构成阵列测量探头,分别利用油气与水的导电特性和介电特性差异辨识井内流体,对流动截面的测量局限于个别点上,已在水平井中见到应用效果,但对物场信息投影测量的数据量和分辨率未能满足成像要求。我国提出的电磁法采用环状阵列电极构成测量探头,综合利用油气与水的导电和介电特性差异辨识井内流体,可以测量获得多相流体流动截面的清晰图像,为研究开发全新的流动成像测井系统奠定了良好基础。 相似文献
34.
Che Yong-tai Yu Jin-zi Zhang Shu-liang Fan Xue-fang Guo Jun-jie Zhang Tian-yuan Yang Jin-lan 《地震学报(英文版)》2002,15(2):226-233
A lot of slow fluctuations of water level have been observed in the original recording maps of subsurface fluid in Well Shuozhou,
Shanxi Province. Some typical recording maps of the “precursors” are introduced in the paper and the features of the “precursors”
recorded by the well are analyzed. The results show that 38% strong earthquakes possess this kind of record, which has a fluctuation
period arranging from several to tens of minutes and appear mostly two days before the earthquakes. Moreover, the mechanism,
transmission and responding conditions of well water level are discussed, as well as the scientific meaning and practical
value of the “precursor” of the well water level in earthquake predictions.
Foundation item: State Natural Science Foundation of China (19973011). 相似文献
35.
大姚地热动态特征分析 总被引:3,自引:1,他引:3
通过大姚高精度水温观测井水地质、井孔条件的分析,震例观测资料、实验观测数据的处理,以及井水水质分析结果,表明大姚水温周期性变化的突出位置是井深75m左右,根本原因是该地层石膏脉稳定释热,含水层热水与井内冷水混合过程中,在通道内形成钙盐类沉淀物(如CaSO4CaCO3),堵塞对流通道,含水层内外压差突破被阻塞通道,热水反复侵入井内,便形成水温周期性变化。地震的孕育、发生和调整过程,由于应力场作用,产生附加地热场,水温基值发生变化,周期畸变或消失,这种附加地热动态是可以恢复的。所以认为大姚地热动态是井区特殊地层地热信息的反映。 相似文献
36.
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38.
分析了天水台数字深井水温资料在陕西石泉ML4.7级地震前的异常特征,发现在震前5天内深井水温发生大幅度的降升变化,呈负脉冲形态,表现为典型的脉冲型前兆异常形态特征。 相似文献
39.
40.
G. Chi P. S. Giles M. A. Williamson D. Lavoie R. Bertrand 《Journal of Geochemical Exploration》2003,80(2-3):171-191
Eighty-two core samples were collected from the Spring Valley #1 well which penetrates the Upper Carboniferous strata in the Late Devonian–Early Permian Maritimes Basin. The strata consist of alternating sandstones and mudstones deposited in a continental environment. The objective of this study is to characterize the relationship of sandstone porosity with depth, and to investigate the diagenetic processes related to the porosity evolution. Porosity values estimated from point counting range from 0% to 27.8%, but are mostly between 5% and 20%. Except samples that are significantly cemented by calcite, porosity values clearly decrease with depth. Two phases of calcite cement were distinguished based on Cathodoluminescence, with the early phase being largely dissolved and preserved as minor relicts in the later phase. Feldspar dissolution was extensive and contributed significantly to the development of secondary porosity. Quartz cementation was widespread and increased with depth. Fluid inclusions recorded in calcite and quartz cements indicate that interstitial fluids in the upper part of the stratigraphic column were dominated by waters with salinity lower than that of seawater, the middle part was first dominated by low-salinity waters, then invaded by brines, and the lower part was dominated by brines. Homogenization temperatures of fluid inclusions generally increase with depth and suggest a paleogeothermal gradient of 25 °C/km, which is broadly consistent with that indicated by vitrinite reflectance data. An erosion of 1.1–2.4 (mean 1.75) km of strata is inferred to have taken place above the stratigraphic column. δ18O values of calcite cements (mainly from the late phase) decrease with depth, implying increasing temperatures of formation, as also suggested by fluid-inclusion data. δ13C values of calcite cements range from −13.4‰ to −5.7‰, suggesting that organic matter was an important carbon source for calcite cements. A comparison of the porosity data with a theoretical compaction curve indicates that the upper and middle parts of the stratigraphic column show higher-than-normal porosity values, which are related to significant calcite and feldspar dissolution. Meteoric incursion and carboxylic acids generated from organic maturation were probably responsible for the abundant dissolution events. 相似文献