西南太平洋热流和海底沉积环境分析

本文对西南太平洋海域(145°E—170°W,0—40°S)内271个海底热流数据进行了数值分级、质量分等和测点沉积环境分类,阐明了海盆的沉积环境类型对其热流的统计分布特征起主控作用;并应用全球洋壳热演化模式的理论曲线,拟合边缘海盆区的热流和海底深度随洋壳年龄的变化,结果表明,两者演化机制接近相似。     

THERMAL RESERVOIR MODEL ANALYSIS OF THE YANGBAJING GEOTHERMAL FIELD,XIZANG (TIBET) AUTONOMOUS REGION

Based on the analyses of temperature field in subsurface geothermal reservoir aud un-derlying granitic batholith of the Yangbajing Geothermal Field, both the difference in res-servoir eharacters of the northern and southern parts of the field and their identity in heatervoir characters of the northern and southehave been ascertained. Furthermore, it hasbeen establishedt hat the Nyainqentanglha and Tanggulashan piedmont fault zones are thecontrolling structures for the boundary of the geothermal field; meanwhile, the distributionof lithological character of the Quaternary system in the reservoir is the main controllingfactor for the geothermal reservoir behaviours. In accordance with the temperature datafrom the deep drill holes in the geothernml field, a heat transfer model down to a depth of3.3 km in basement rocks has been worked out. Using the principles of transient heat trans-fer and heat balance a rough estimate has been obtained that the last hydrothermal fluidinjection into the geothermal reserv     

HEAT FLOW ON THE QINGHAI-XIZANG(TIBETAN) PLATEAU AND THE MODELING OF THE TECTONO-THERMAL EVOLUTION

Thirteen observed heat flow values in combination with relevant geological and geophysical information are employed in the current paper to conduct a model study by means of direct inversion. The modeling demonstrates the tectono-thermal evolution of the Tibetan Plateau during the last 40 Ma since the continent-continent collision. The authors stress the fact that the tectonic deformations of terranes are usually the inducing factors for the deep-seated thermal activities in the crust and upper mantle. On this basis a series of kinematic equations of 3-D deformations of terranes in forms of shortening-thickening-uplifting-erosion-mass sliding were deduced using the principle of plate kinematics. These equations are further used as systematically defined initial and boundary conditions for simulating the integrated processes of tectono-thermal evolution, The results of the model study suggest that there exist sharp differences in the tectono-thermal evolution between the old northern terranes and the new     

西藏羊八井热田的热储模式分析

通过对羊八井热田浅层热储及下伏花岗岩基温度场的分析,阐明了热田南北两部分热储特性的差异性和热液补给的同源性,进一步得出:念青唐古拉山前断裂带和唐山山前断裂带是热田的边界控制构造,而热储内的第四系岩性分布则是热储特性的主要控制因素.依热田内深孔温度资料,建立了深及3.3km的基岩区传热模式,应用非稳定热传导和热量平衡原理,粗略估算出最近一次热液侵入浅层热储的年代约为距今数万年左右,是青藏高原最新的深部热活动在近代构造应力作用下的地表显示。     

青藏热流与构造热演化模型研究

本文以13个实测热流值为主,综合了有关地质-地球物理资料,通过正演拟合的模型研究,展现了青藏高原自陆-陆碰撞以来的40Ma间地体的构造热演化过程。文中着重强调地体构造变形是壳幔深部热作用的主要诱发因素,据此用板块运动学原理推导出地体的缩短-增厚-抬升-侵蚀-滑移等三维变形的运动学方程组,作为模拟地体综合构造热演化过程的系统定义的初始和边界条件。模型研究结果表明:青藏高原南北新老地体的构造热演化差异很大,但南部热地体中深部热过程的规模比预期的水平要低。     

HEAT FLOW AND SEA-BOTTOM SEDIMENTARY ENVIRONMENT ANALYSIS OF SOUTHWEST PACIFIC

In this paper a compilation of 271 heat flow values of the Southwest Pacific (145°E-170°W and 0--40°S) is presented with division of data categories, quality gradation add sedi-mentary environment classification. The dominating effect of environmental types of thebasins on the characteristics of statistical distribution of heat flow data is illustrated. A plotmatch of heat flow and ocean depth versus age of oceanic crust in the marginal seas with thetheoretical curve of thermal evolution derived for the world oceans has been accomplished forthe first time. The result reveals an approximate similarity in the mechanism of their evolution.