Temperature dependence of thermal conductivity and its impact on assessments of heat flux

The variability of sedimentary thermal conductivities with increasing temperature are explored for their impact on estimates of present-day heat flux and subsurface temperature gradient. For sand thicknesses less than about 10–20 km, or shale thicknesses less than about 40–80 km, the subsurface temperature is closely linearly proportional to the thermal resistance integral obtained in the absence of the temperature dependence of thermal conductivity. Estimates of heat flux should be increased (decreased) by about 5% for sands and decreased by about 1% for shales. For salt, because of the much shorter temperature range over which its thermal conductivity decreases, effects produced by the temperature dependence are more noticeable: heat flux should be increased by around 13%, salt thicknesses in excess of 5 km will yield major (around 30–100°C) changes in their temperature regimes solely as a consequence of the temperature-dependent thermal conductivity, and the linear increase of temperature with increasing thermal resistance is not an adequate approximation but has to be replaced with a more exact exponential increase.The impact of the variations, particularly in the case of salt, for geologic processes is briefly considered.     

岩石的热惯量研究

本文阐述了热惯量的物理意义及其在地质遥感中的作用。在测得２３种岩石热物理性质的有关参数──热传导率、热容量和密度的基础上，计算并列表给出了岩石的热惯量值和热扩散系数等基础数据。文中分析讨论了沉积岩、变质岩和岩浆岩岩石的热惯量变化由高到低的初步规律。取得了碳酸盐岩和砂岩类等沉积岩和沉积浅变质岩的热惯量差异的结果，指出了它们的易区分性；也指出了中－酸性、碱性岩浆岩之间的热惯量值差异较小，不易区分。     

下庄矿田基底的控矿作用及其有关地质问题

本文提出武夷及其邻区存在两个裂陷槽及一裂隆，鹰潭－南城－安远－河源韧性断裂带为东部的火山岩型与西部的花岗岩型铀矿床的地质分界线，指出了加里东运动在本区的突出作用是使裂隆基底岩石发生混合花岗岩化作用。根据下庄矿田及其外围发现较深变质的岩石和较大规模韧性剪切糜棱岩带，得出下庄矿田是古老基底加里东热穹隆区多次构造、岩浆活动的产物。由于铀成矿作用赋存于初、脆性两种构造中，建议重新划分矿化类型以指导勘查工作。     

Thermal properties as controls on rock surface temperature maxima,and possible implications for rock weathering

Four rock types (basalt, sandstone, granite, and chalk) are examined with respect to the maximum surface temperatures which they experience when subjected to similar conditions of exposure. Rock temperature measurements are reported for an urban environment and for two experimental situations in which an infrared lamp is used to simulate heating under cold and hot conditions. Differences in rock temperatures are discussed with reference to thermal rock properties (albedo, specific heat capacity, and thermal conductivity). Some natural situations are suggested in which thermal rock properties could conceivably play a role in determining the extent to which rocks would be affected by particular weathering processes.     

天然气水合物的地热研究进展

天然气水合物的地热研究在以下几个方面都取得了重要进展，热流与似海底反射层的关系，水合物稳定带的研究；水合物热物理参数的确定；水合物形成过程中的热状态；热导率的应用，指出了今后水合物的地热学研究方向。     

Climate induced temperature effects on growth performance, fecundity and recruitment in marine fish: developing a hypothesis for cause and effect relationships in Atlantic cod (Gadus morhua) and common eelpout (Zoarces viviparus)

Effects of global warming on animal distribution and performance become visible in many marine ecosystems. The present study was designed to develop a concept for a cause and effect understanding with respect to temperature changes and to explain ecological findings based on physiological processes. The concept is based on a wide comparison of invertebrate and fish species with a special focus on recent data obtained in two model species of fish. These fish species are both characterized by northern and southern distribution limits in the North Atlantic: eelpout (Zoarces viviparus), as a typical non-migrating inhabitant of the coastal zone and the cod (Gadus morhua), as a typical inhabitant of the continental shelf with a high importance for fisheries.Mathematical modelling demonstrates a clear significant correlation between climate induced temperature fluctuations and the recruitment of cod stocks. Growth performance in cod is optimal at temperatures close to 10°C, regardless of the population investigated in a latitudinal cline. However, temperature specific growth rates decrease at higher latitudes. Also, fecundity is less in White Sea than in North and Baltic Sea cod or eelpout populations. These findings suggest that a cold-induced shift in energy budget occurs which is unfavorable for growth performance and fecundity. Thermal tolerance limits shift depending on latitude and are characterized by oxygen limitation at both low or high temperatures. Oxygen supply to tissues is optimized at low temperature by a shift in hemoglobin isoforms and oxygen binding properties to lower affinities and higher unloading potential. Protective stimulation of heat shock protein synthesis was not observed.According to a recent model of thermal tolerance the downward shift of tolerance limits during cold adaptation is associated with rising mitochondrial densities and, thus, aerobic capacity and performance in the cold, especially in eurythermal species. At the same time the costs of mitochondrial maintenance reflected by mitochondrial proton leakage should rise leaving a lower energy fraction for growth and reproduction. The preliminary conclusion can be drawn that warming will cause a northern shift of distribution limits for both species with a rise in growth performance and fecundity larger than expected from the Q₁₀ effect in the north and lower growth or even extinction of the species in the south. Such a shift may heavily affect fishing activities in the North Sea.     

EXPERIMENTAL GEOCHEMISTRY STUDY ON GOLD IN WATER-ROCK REACTION UNDER THERMAL FLUID SYSTEM AT MESO-LOW TEMPERATURE

Based on the knowing geochemical characteristics of wall rock in the Mobin gold deposit and composition of fluid inclusion in ore,water-rock experiments were carried out,important achievements are acquired as following: Gold is mainly derived from the ore-bearing wall rock,i,e.,a series of epimetamorphic clastic gritstone,sandy slate,and tuffaceous slate in the Wuqiang Banxi Formation,Wuqiangxi Group.In thermal system with middle-low temperature chlorine gold may be derived form stable complex ions,so it is quite important in gold metallogenic process.Sulphur and chlorine perform as the major negative ions throughout the gold activation and migration movement.The concentration of sulphur and chlorine ions,pH value and temperature are of deciding significance for gold activation,migration and precipitation.     

Application of the photoacoustic method for characterization of natural galena (PbS)

Electron transport properties of single crystal and polycrystalline natural mineral galena (PbS) samples from the Trep?a mine, Yugoslavia, were determined using the photoacoustic frequency transmission technique. Their thermal diffusivity (D _T≈0.16 × 10^?5 m² s^?1), the coefficient of diffusion (D between 0.15×10^?2 0.16×10^?2 m² s^?1) and lifetime of the excess carrier (τ≈35 μs and the front and rear recombination velocity (s _g≈65.5 m s^?1 and s _b≈66.4 m s^?1, respectively), were calculated by comparing the experimental results and the theoretical photoacoustic amplitude and phase signals. The lattice parameter obtained by X-ray work was a?=5.936?Å. The free carrier concentration of these single-crystal samples was measured using the Hall method (N?=?3×10¹⁸ cm^?3). Measurements of the optical reflectivity of the same samples, as a function of wavelength, in the infrared and far infrared ranges, were performed. In the far infrared range a free electron plasma frequency was observed and numerically analyzed, using the least-squares fitting procedure. The values of optical parameters were calculated and the value of the free carrier concentration obtained by the Hall method was confirmed.     

320矿床成因和找矿方向

320矿床的含矿土岩是一套强烈硅化(角)砾状和(角)砾质岩,是地洼初动期岩溶洞穴沉(堆)积岩——以钙屑岩为主的混杂陆源沉积岩,受硅化形成。硅化主要发育于岩溶沉积岩中,并波及它附近的地层。这一事件发生于地洼余动期初,形成于低温环境,硅来自沉积岩源,流体起源于大气降水。320矿床是一个硅化改造的古岩溶矿床,它与美国亚利桑那州的硅化溶解-塌陷角砾岩筒相同。这类矿床在华南碳酸盐岩地区找矿潜力很大。     

High-temperature X-ray investigation of natural columbites

Structural investigations at high temperature were carried out on natural columbite samples across the join Fe(Nb_0.95Ta_0.05)₂O₆–Mn(Nb_0.95Ta_0.05)₂O₆. The samples were preliminarily annealed to attain the complete cation-ordered state and avoid the superimposition of the effects of cation ordering during high-temperature studies. Unit-cell parameters of three columbites with different X_Fe content were measured at regular intervals in the temperature range 25–900 °C using single-crystal X-ray diffraction techniques. The crystal structures of completely ordered ferrocolumbite and manganocolumbite were also refined from intensity data collected at room temperature, 300 and 600 °C. Structural thermal expansion coefficients show positive, linear expansion of a, b, c lattice constants and cell volume. In general, slightly higher expansion occurs along a and c directions. However, anisotropy decreases sharply with decreasing Fe content. Reversibility of thermal expansion in the investigated temperature range was checked by high-temperature diffraction studies under heating-up and cooling-down conditions. Impurities do not play an important role in thermal expansion of columbites; expansion coefficients measured on two crystals of the same sample characterized by different Ti content are in fact almost identical. Structural changes with temperature essentially affect bond lengths: volumes of both A and B octahedral sites increase linearly with temperature, whereas interpolyhedral geometrical parameters do not vary significantly.