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911.
Geothermal gradients are estimated to vary from 31 to 43 °C/km in the Yinggehai Basin based on 99 temperature data sets compiled from oil well data. Thirty-seven thermal conductivity measurements on core samples were made and the effects of porosity and water saturation were corrected. Thermal conductivities of mudstone and sandstone range from 1.2 to 2.7 W/m K, with a mean of 2.0±0.5 W/m K after approximate correction. Heat flow at six sites in the Yinggehai Basin range from 69 to 86 mW/m2, with a mean value of 79±7 mW/m2. Thick sediments and high sedimentation rates resulted in a considerable radiogenic contribution, but also depressed the heat flow. Measurements indicate the radiogenic heat production in the sediment is 1.28 μW/m3, which contributes 20% to the surface heat flow. After subtracting radiogenic heat contribution of the sediment, and sedimentation correction, the average basal heat flow from basement is about 86 mW/m2.Three stages of extension are recognized in the subsidence history, and a kinematic model is used to study the thermal evolution of the basin since the Cenozoic era. Model results show that the peak value of basal heat flow was getting higher and higher through the Cenozoic. The maximum basal heat flow increased from 65 mW/m2 in the first stage to 75 mW/m2 in the second stage, and then 90 mW/m2 in the third stage. The present temperature field of the lithosphere of the Yinggehai Basin, which is still transient, is the result of the multistage extension, but was primarily associated with the Pliocene extension. 相似文献
912.
I. E. Paukov N. K. Moroz Yu. A. Kovalevskaya I. A. Belitsky 《Physics and Chemistry of Minerals》2002,29(4):300-306
The heat capacity of paranatrolite and tetranatrolite with a disordered distribution of Al and Si atoms has been measured
in the temperature range of 6–309 K using the adiabatic calorimetry technique. The composition of the samples is represented
with the formula (Na1.90K0.22Ca0.06)[Al2.24Si2.76O10]·nH2O, where n=3.10 for paranatrolite and n=2.31 for tetranatrolite. For both zeolites, thermodynamic functions (vibrational entropy, enthalpy, and free energy function)
have been calculated. At T=298.15 K, the values of the heat capacity and entropy are 425.1 ± 0.8 and 419.1 ±0.8 J K−1 mol−1 for paranatrolite and 381.0 ± 0.7 and 383.2 ± 0.7 J K−1 mol−1 for tetranatrolite.
Thermodynamic functions for tetranatrolite and paranatrolite with compositions corrected for the amount of extraframework
cations and water molecules have also been calculated. The calculation for tetranatrolite with two water molecules and two
extraframework cations per formula yields: C
p
(298.15)=359.1 J K−1 mol−1, S(298.15) −S(0)=362.8 J K−1 mol−1. Comparing these values with the literature data for the (Al,Si)-ordered natrolite, we can conclude that the order in tetrahedral
atoms does not affect the heat capacity. The analysis of derivatives dC/dT for natrolite, paranatrolite, and tetranatrolite has indicated that the water- cations subsystem within the highly hydrated
zeolite may become unstable at temperatures above 200 K.
Received: 30 July 2001 / Accepted: 15 November 2001 相似文献
913.
The permeability of sedimentary rocks during triaxial compression tests was investigated to relate it to the complete strain–stress process. It was found that the permeability was not constant, but varied with the stress and strain states in the rocks. Prior to the peak strength, the permeability decreases with increasing load. A dramatic increase in permeability occurs during the strain softening period. In the present study, in situ measurements of fluid flow and pressure in floor strata was carried out in a double longwall mining face in the Yangzhuang colliery. These measurements show that both the strata pressure and the position with respect to the mining face influence the hydrogeologic properties. The permeability increased in the floor strata behind the mining face because those mining induced fractures opened as the strata pressure decreased. To better understand this change in hydraulic behavior around the mining faces, 3-D numerical modeling was carried out. The model provides the general picture of the stress distribution and failure zone both in the floor and roof strata. The field and model results demonstrate the importance of changes in the stress and strain states on the hydrogeology of a site. 相似文献
914.
The mode of occurrence of gold in the Yata micro-disseminated gold deposit is ap-proached through chemical phase studies coupled with ore-dressing monitoring and micro-beam analysis.The results showed that gold occurred for the most part as ultra-microscopic particles adsorbed on the surfaces or fracture planes of pyrite and other sulphides.The proportions of gold of different occurrences were estimated solutions containing nanometer-sized gold particles were prepared following the hydrolysis-reduction procedure and the adsorption of nanometer-sized gold on ordinary sulphides and rocks was experimentally determined.It is evident that sulphides are good adsorbents of gold and this is consistent with geological observations. 相似文献
915.
Refined analytical expressions for the frequencies corresponding to the Chandler motion of the pole and the diurnal rotation of the deformable Earth are derived. Numerical estimates of the period and amplitude of the polar oscillations are presented. The trajectory of the Chandler polar motion derived via numerical modeling is in qualitative and quantitative agreement with experimental data from the International Earth Rotation Service (IERS). An evolutionary model describing slow variations in the Earth’s rotation parameters under the action of the dissipative moments of the tidal gravitational forces on time scales considerably longer than the precession period of the Earth’s axis is constructed. The axis of the Earth’s figure tends to approach the angular momentum vector of the proper rotation. 相似文献
916.
917.
1999年山西大同Ms 5.6地震的震源断层 总被引:9,自引:0,他引:9
大同震区先后在 1989、1991和 1999年发生MS >5地震 ,利用大同遥测地震台网的记录资料进行比较精确的地震序列震源定位 ,结合宏观烈度分布和震源机制解资料 ,详细地分析对比了 3次子序列的异同。结果显示 ,1999年MS5 .6地震的震源断层是走向NWW、长 16km、宽12km、埋深 5km以下、倾角近直立的左旋走滑断层。而前 2个子序列是NNE为主的右旋走滑断层活动所致 ,表明地震破裂方向发生了变化。这种 2个以上方向先后出现、并且强弱有别的地震破裂是普遍存在的 ,表明震源环境的复杂程度与地震序列的类型有关。虽然震区存在NE向的大王村断裂和NW向的团堡断裂 ,但目前没有证据说明震源断层和 2条构造断层连通。 3次子序列的震源断层都是走滑断层 ,也和 2条构造正断层有别。 1999年的子序列可能属于新破裂。 相似文献
918.
人工值守台数字化地震仪标定原理 总被引:1,自引:0,他引:1
推导了人工台数字化地震仪的分段标定公式,提出数字化记录系统的微分近似标定和拾震器阻尼衰减法标定的方法,并提供了不同短周期地震仪与数字化地震仪并行的藕合方式和标定计算公式。 相似文献
919.
为弄清山西夏县中心地震台水氡震前异常的原因 ,对山西夏县中心地震台热水井水氡 1984年以来的观测资料用概率论的数据处理方法进行了处理 ,以负异常的发震原理进行了分析 ,结果表明震前负异常的发震概率为 70 %。 相似文献
920.
圆弧状沉积盆地与软土单覆盖层出平面地表运动对比 总被引:2,自引:0,他引:2
采用解析方法,通过圆弧状沉积盆地与同样参数的软土均匀单覆盖层的对比,研究沉积盆地对平面SH波二维散射效应和其出平面地表运动。数值对比结果表明:(1)波垂直入射时盆地中央地表位移幅值反应,其随频率变化形式与软土单覆盖层的地表运动有较强的对应性,且此时单覆盖层地表位移幅值为其下降;(2)盆地的二维散射效应特点显著波的汇聚作用使盆地中的地表运动显著放大,总体上较软土单覆盖层的地表位移幅值要大,其频域内的最大反应则明显大于单覆盖层情况,但最大反应在盆地表面出现的位置依赖于入射波角度、盆地深宽比和盆地的软硬程度;(3)沉积盆地中地表位移运动有强烈扭转效应,且随盆地变软和入射波频率增高而增强。 相似文献