Thermal structure of the Barbados accretionary complex   总被引：2，自引：0，他引：2  

Yaolin Shi  Chi-Yuen Wang 《Pure and Applied Geophysics》1988,128(3-4):749-766

Finite element modeling of the thermal structure within the Barbados subduction complex is carried out. Kinematics of the sediments inside the complex are computed from a viscous model with inhomogeneous viscosity and the effect of gravity. The model yields an uplift rate compatible with observational data. Advective heat transfer affects the heat flow across the complex. Imbricated thrust faulting further reduces the heat flow across the slope. These mechanisms predict an arcward decrease of heat flow on the lower slope, followed by an increase of heat flow approaching the ridge, little change in heat flow at the forearc basin, and a significant increase of heat flow near the volcanic are, in agreement with the existing observations.  相似文献   

Application of fluid mechanic principles to the study of geodynamic processes at trench-arc-back arc systems     

Albert T. Hsui 《Pure and Applied Geophysics》1988,128(3-4):661-681

Geological processes at trench-arc-back arc systems are some of the most complex tectonic processes in need of study. A large amount of data based on geological and geophysical observations has been accumulated. To synthesize these data, mathematical models have proven to be very useful. Because geological processes are directly related to the dynamical behavior of the solid earth, many of them can be investigated in terms of fluid flow models. Some applications of fluid flow principles in studying tectonic processes at convergent plate boundaries are discussed in this paper. When mantle processes are modeled as convective systems, they are found to have direct implications for the determination of slab dip angles. Additionally, they can also account for the high heat flows in the back arc basins, provide a mechanism for back arc opening, and resolve the question whether subducted oceanic crust can reach melting at shallow depth for island arc magma generation. Besides mantle processes, flow models can also be used to study surface processes. A simple one-parameter plane flow theory is used to model the evolution of trench geometries. This model is able to fit simulataneously the trench curvature and the differential paleomagnetic rotation between volcanic islands for the Mariana. Despite the simplicity of many of these models, their ability to synthesize geological and geophysical data at convergent plate boundaries is quite remarkable.  相似文献   

吉林中部环形构造及其控矿作用     

Liu Zhansheng Ma Xuemin 《吉林大学学报(地球科学版)》1989,(4)

吉林中部环形构造是中生代形成与演化的热点构造。这个环形构造主要由外环带的环形断陷火山含煤盆地,中心区的断焰火山含煤盆地和火山机构,以及呈现环带状分布的花岗岩成因系列等部分组成,其形态呈现圆形,直径270km。 吉林中部环形构造控制外生煤、油气矿床、内生多金属和金矿床的形成和分布规律,从而为这些矿产资源的预测提供了可靠的地质依据,并获得实际效果。  相似文献   

有机质的热液成熟作用在云南金顶铅锌矿床形成过程中的意义   总被引：16，自引：0，他引：16  

胡明安 《地球科学》1989,14(5):503-512

  相似文献   

从空间测量陆面温度的可行性     

万正明  道席 《遥感学报》1989,(2)

为了将用于从卫星热红外数据测量海面温度的多波段方法应用到陆面温度的测量,我们通过大气辐射输运模型的模拟计算进行了可行性研究。所模拟的大气条件和表面温度的变化范围宽得足于覆盖晴天大气性质和表面温度的实际变化,这些变化对陆地来说比对海洋的大。地面高程也作为最重要的地形影响包括在模拟计算中。用频谱发射率的测量值或计算值表征的地面覆盖,包括雪、粘土、沙地和树叶的样品。从统计分析得到的经验反演模型在无云条件下可由卫星三个红外波段测量,较精确地估算陆面温度,在0—40°观察角范围内,其标准偏差小于0.3 K,最大误差小于1K。热红外波段可以是气象卫星甚高分辨率辐射计(AVHRR),也可以是正被EOSAT和NASA考虑用于将来遥感测量的传遥器,即陆地卫星上增加的热红外多波段或为陆面/海面测量设计的宽视野传遥器(Sea WiFS)。  相似文献   

永平铜矿床中钼矿的矿源与成矿     

鲁重华 《华东地质学院学报》1986,(2)

本文论述了永平铜钼矿床的矿质来源主要来自于混合岩化作用以前形成的原始含矿地层;其成矿是由于变生热液在动力和热力作用下,萃取了己被混合岩同化的矿源层中的矿质,形成含矿的变生热液,在迁移过程中,选择在矿源层残留块体或其毗邻地段,形成愿地、半原地的由含矿变生热液迭加而富集的铜、钼矿体.  相似文献   

羟钒锌铅矿在中国的首次发现与研究          下载免费PDF全文

丁奎首  臧启家  崔文元 《地质科学》1987,(4):358-363

文中之羟钒锌铅矿系国内首次发现,用化学分析、X射线法、差热、红外光谱等手段进行了研究。 矿物呈黄褐色完美的晶簇,比重6.14,成分、结构及物理性质和国外同类矿物相同。作者重点地研究了它的热相变全过程,进而指出这是一种和多金属硫化矿床有关的次生矿物。  相似文献   

地热—Ⅱ型稳定分棒式热导仪——岩石热导率精密测量装置     

沈显杰  张文仁  陆秀文  杨淑贞 《岩石学报》1987,3(1)

地热-Ⅱ型岩石热导仪是在地热-Ⅰ型基础上,参考美、法同类装置的性能特长,改型设计研制而成的。采用了国际地热界通用的一维稳态分棒原理和结构,并成功地应用了计算机程控测量。仪器为平行双架式,可同步运行。该测试系统尚配备微型探针,程序兼容,仪表共用。因此,除坚硬致密岩样外,尚可用于测量孔隙含水或饱水岩样、松散沉积物或钻孔岩屑。仪器性能稳定,操作方便,自动打印结果。测量复率±2—3％,绝对精度优于±5％。  相似文献   

黄铁矿、菱铁矿、白云石在不同气氛下热行为的研究——QDTA/T/EGD/GC在线联用技术(Ⅶ)     

蔡根才 《矿物学报》1989,(4)

应用差热分析(DTA)/逸气检测(EGD)/气相色谱(GC)在线联同技术及其装置,对黄铁矿、菱铁矿、白云石在N_2、Air、CO_2、Air/CO_2气氛下的热行为进行了研究。依据测得的DTA/EGD/DC曲线所提供的信息,探讨了黄铁矿热氧化分解反应历程;鉴定了菱铁矿中的含硫杂质;考察了白云石在N_2、Air、CO_2气氛下的热行为。实验结果表明,把热分析与高灵敏度的逸气检测/逸气分析的联用技术应用于矿物学研究领域中,将更发挥其潜在的优越性和独特的效用。  相似文献   

Evidence for periodic seismicity in the inner Aegean seismic zone     

G. A. Papadopoulos  Ph. Voidomatis 《Pure and Applied Geophysics》1987,125(4):613-628

The most complete and reliable data of strong (M _s6.5), shallow (h<70 km) earthquakes which occurred in the inner Aegean seismic zone have been utilized to describe its seismicity time variation during 1800–1986 by two independent statistical models. The first is a sequentially stationary model of seismicity rates which shows that intervals of low seismicity rate, lasting for some 37 years, alternate with high rate intervals of 8–12 years duration. The second model is a statistical model according which seismic energy released within 5-year time windows approximates a harmonic curve within a period of about 50 years. This model is in agreement with the notion that the time series of strong earthquake occurrences in the inner Aegean seismic zone consists of a random (shocks withM _s=6.5–6.8) and a nonrandom component (M _s6.9). Maxima and minima of the harmonic curve coincide with the high and low rate intervals, respectively. A model of regional stationary accumulation of thermal stresses along certain seismic belts and their cyclic relaxation may explain this periodicity.  相似文献