大陆岩石圈的热-流变底边界——以Kaapvaal、Fennoscandia和Slave克拉通为例

板块构造理论的一个基本假设是相对刚性的岩石圈板块漂浮在相对软弱的软流圈之上作欧拉运动.岩石圈与软流圈间存在边界面称为岩石圈-软流圈边界(LAB).提出一种半解析方法来确定大陆LAB:定义其为有效黏度取极小值所在的深度.该方法得到的LAB,综合考虑了大陆岩石圈地幔介质的热学和流变学性质,故称其为热-流变底部边界.对3个著名克拉通(Kaapvaal,Fennoscandia和Slave)的研究表明:3个克拉通的热-流变底部边界在~250km,与大地电磁测深等其他地球物理方法得到的结果一致.因为热-流变底部边界是从力学的角度来定义的,且提供了岩石圈板块浮于软流圈上运动的极大可能性,因而与板块构造理论的定义更为接近.在该边界及附近,主导的流变机制是湿橄榄石的扩散蠕变,有效黏度极小,差应力小,应变率相对较大.     

塔里木盆地巴楚隆起与塔北隆起构造-热演化的对比分析

巴楚隆起和塔北隆起具有相似的的构造特征.从构造-热演化的角度出发,恢复了这2个地区沉积埋藏史、构造沉降史以及热演化史.通过对比分析,可以看出巴楚地区热流一直大于塔北地区,这可能导致巴楚地区生烃期早,而巴楚区隆起发育时间晚,后期断裂活动又比较剧烈,这些不利因素导致了巴楚地区勘探进展不如塔北地区理想.     

南海中央海盆热结构及其地球动力学意义

依据南海中央海盆大地热流观测值及地壳结构资料 ,利用地热学方法计算了海盆及周缘壳内温度和热流分布 ,并得出壳幔热结构配分比例 .计算结果表明 ,中央海盆洋壳层内垂向热流变化不大 ,但垂向温度变化较大 ,这是地幔上涌所致 .海盆内成片分布的地热区 ,则是局部地区地幔上涌 ,导致多期次、多方向海底扩张的反映 .海盆区地幔热流在地表实测大地热流中所占比例高于 80 %,地壳下部热流在地壳总热流中所占比例小于 2 0 %.由此推测 ,中央海盆洋壳层 3厚度过薄 ,可能是后期热事件减缓了上地幔的冷却过程 ,而初始地壳熔融程度较低 ,2种因素综合所致     

地热系统地热流体流动模型及勘查靶区预测 ——以桐庐县阆里村石峦坞矿区DR1地热井为例

以桐庐县阆里村石峦坞矿区DR1地热井为例,通过对DR1地热井周边的区域构造、断裂构造、地层岩性及水文地质特征等进行综合分析,并运用建立的地热系统地热流体模型将DR1地热井位置选于区域复向斜构造内,阆里背斜的东翼,F_3、F_6、F_7断裂形成的三角区内,以富水性好的灰岩与非灰岩交界断层F3作为耙区断层。经过CSAMT物探测线及后期钻孔工作验证,成功勘探出水温为34. 6℃,水量936 m~3/d的地热水,地热资源储量7. 2×10~(14)J。满足了构造裂隙型带状热储地热找水需要查明储水空间及富水性这两个最基本的问题,对浙江地区构造裂隙型带状热储地热找水具有一定的指示意义。     

大地电磁测深法在阜阳市地热资源可行性勘查中的应用

大地电磁测深法是研究地壳岩石圈至上地幔构造的一种地球物理深部探测方法。它是以天然交变电磁场为场源的频率域电磁测深法,利用大地电磁测深法反映地质体的电性差异,可以确定具有不同电性特征的地质体的空间展布。在本次地热资源勘查中,利用大地电磁法解译断裂带的走向和产状、地层结构界线(热储及盖层)、松散层厚度、基底分布,圈定地热异常区,取得了一定的成果。     

论五大连池地区地热特征

总结了五大连池地区地热地质背景、地表热显示、深部信息显示的地热特征,指出寻找坳陷型与隆起型地热田有利地区,论证了存在的地热异常区,提出进行地热勘查工作的依据和建议。     

板内造山作用与成矿

中国大陆广泛分布强烈的板内变形和造山作用，传统的板块构造理论常常将其解释为板块边缘汇聚力的远程效应。然而，中国大陆的板内造山作用与汇聚板块边界之间缺乏可预期的动力学联系，不能简单地解释为大陆碰撞或板块俯冲的远程效应。本文提出另一种可供选择的解释，认为板内变形主要取决于岩石圈不均一性。相邻的板块拼合在一起形成统一板块之后，区域地质演化进入板内阶段。板块碰撞导致的岩石圈不均一性和重力不稳定性可以触发强烈的板内变形甚至造山作用，其延迟时间的长短取决于岩石圈不稳定性的程度和地球深部的热扰动。与板缘造山带相比，板内造山作用缺少板块俯冲．碰撞过程，板内造山带的演化历史相对简单，通常是以岩石圈拆沉作用开始，以地壳的垂向增生为特征，最后以岩石圈拆沉作用结束或形成重力不稳定岩石圈。因此，板内造山作用一般沿着古造山带发育。古造山带岩石圈结构低成熟度的特点不仅是岩石圈不稳定性的主要原因之一，而且由于挥发分和含矿元素的富集在活化过程中具有很强的成矿潜力。板内造山带的成矿作用依赖于深埋在岩石圈-软流圈系统不同深度水平上含矿流体的突然释放，主要发生在造山作用初始阶段和造山后伸展阶段。     

论五大连池地区地热特征

总结了五大连池地区地热地质背景、地表热显示、深部信息显示的地热特征,指出寻找坳陷型与隆起型地热田有利地区,论证了存在的地热异常区,提出进行地热勘查工作的依据和建议。     

矿井热涌水防治界定指标体系的建立

针对矿井涌水、淋水对深部矿井日益严重的热害影响以及由于其无规律性、不可预测性导致涌水、淋水难以治理的难题,文章提出了矿井热涌水的概念并专属定义为温度超过30℃的矿井淋水和涌水。通过对涌水和淋水的综合分析,确定了8个矿井热涌水评价指标,并采用“专家咨询法”确定了指标权值;最后采用“相对重要性序列矩阵法”将热涌水评价指标简化为热涌水量、热涌水温度、风流温升三个指标,最终建立了一个科学、实用、快速、准确的矿井热涌水防治界定指标体系,为矿井热涌水的治理提供决策参考。     

辽西100Ma火山事件的动力学过程及其构造背景

通过辽西及邻区106Ma来源于软流圈亏损地幔玄武岩的年代学及玄武岩底部不整合面的研究,认识到：（1）这一时期伴随岩石圈地幔物质的更新,存在着“岩浆间隙”和强烈构造运动的现象,从而推断软流圈底辟体上涌、岩石圈减薄、岩浆活动间隙、强烈构造运动这四者之间的因果关系,其中被软流圈熔体带上来的物质和热能是主导因素,岩石圈减薄是关键;（2）106Ma与116Ma、93Ma、80Ma、45Ma火山岩之间的对比研究,表明106Ma开始的岩石圈地幔的更新是一个漫长的不可逆转的过程.（3）通过本区火山岩的演变与相邻大洋板块同期热扩张历史的对比研究,推测晚中生代（120～80Ma）大洋与大陆岩石圈板块同步的演化特征可能反映了它们共同受到岩石圈板块之下同一深部热扰动的控制.     

海洋和大陆岩石圈下的混合地幔对流模型

运用参量化模型方法,建立了海洋岩石圈板块和大陆岩石圈板块下混合地幔对流模型．计算结果表明：板块构造和地幔对流的相互作用,造成在地球演化的晚期海洋岩石圈板块和大陆岩石圈板块下的地幔幕式翻转不同步,导致海洋板块和大陆板块之间的边缘地带成为构造活跃地区．     

我国地热能开发利用现状与发展

我国地热资源相当丰富,应用潜力巨大,因此,大力发展地热能能够缓解能源供应紧张局面,很大程度上解决因大量使用化石能源所造成严重的空气污染问题。在我国,应根据资源分布特点制定地热发展规划,在资源品质较好的地区发展地热发电,在有条件的地区发展各种地热直接利用技术,采用综合梯级利用提高资源利用效率。今后开发利用地热能,政府应加大对地热能利用的政策支持,鼓励企业加大资金投入;同时开发商应做好规划和布局,优选技术路线,使得地热能的利用由无序变有序,朝着更加科学合理的方向发展。     

热泉地区岩浆侵入过程的热演化特征

参照腾冲－梁河地热系统的特点及岩浆活动的一般特征,应用二维有限单元法定量模拟了热泉地区岩浆侵入的热演化过程．计算中,采用等效比热方法处理潜热释放问题,同时建立了大气降水对热液循环的补给模型．计算结果表明：半宽度为０．０５～１ｋｍ的侵入体产生的热扰动对热泉地区的影响大致在４ｋｍ的距离范围内     

刘河煤矿地温预测及分析

随着我国煤矿开采深度的增加,地热现已成为制约煤矿企业发展的第六大灾害。为保障刘河煤矿今后深部开采能够安全可靠的进行,必须准确掌握刘河煤矿的地温情况,本文主要通过现场简易测温,对该矿的地温进行预测,并通过数据分析,为今后解决地热问题提供了技术支撑。     

雄安新区地热资源与开发利用研究

雄安新区地热资源丰富且比较容易开采,在生态文明建设中可发挥重要作用。雄安新区浅层(200米)地热能宜于开采;深层(200—3000米)地热能中的砂岩储层和碳酸盐岩储层热量大,宜于开采;超深层(3000米)地热能也具有开采潜力。雄安新区的雄县在利用大型岩溶热储开展规模化供暖方面,单一项目已实现世界最大(450万平方米)供暖能力。文章认为,雄安新区应该加大地热资源勘查力度,重点是超深层碳酸盐岩热储;在利用上,要做到因地制宜,深、浅资源合理配置,还要重视环境保护,协调好与其他资源利用的关系;同时,要发展地热储能技术,形成以地热为主体,多能互补的"地热+"的清洁能源利用新格局。     

Thermal mixing of two miscible fluids in a T-shaped microchannel

In this paper, thermal mixing characteristics of two miscible fluids in a T-shaped microchannel are investigated theoretically, experimentally, and numerically. Thermal mixing processes in a T-shaped microchannel are divided into two zones, consisting of a T-junction and a mixing channel. An analytical two-dimensional model was first built to describe the heat transfer processes in the mixing channel. In the experiments, de-ionized water was employed as the working fluid. Laser induced fluorescence method was used to measure the fluid temperature field in the microchannel. Different combinations of flow rate ratios were studied to investigate the thermal mixing characteristics in the microchannel. At the T-junction, thermal diffusion is found to be dominant in this area due to the striation in the temperature contours. In the mixing channel, heat transfer processes are found to be controlled by thermal diffusion and convection. Measured temperature profiles at the T-junction and mixing channel are compared with analytical model and numerical simulation, respectively.     

太阳能热发电系统基础理论与关键技术战略研究

太阳能热发电技术是将太阳能转化为热能,然后利用热力循环的方法带动发电机发电的热发电技术的简称,是太阳能的高品位利用方式.本文总结了我国在太阳能热发电研究领域的总体布局,分析了太阳能通过热的形式转换成电能需要经过的多个能量转换环节及其涉及的大量基础科学问题,指出了各个能量传递与转换环节的热传递机理及热流特性,光一热一电转换系统的集成理论以及关键材料和技术是太阳能热发电技术中急需解决的重要基础问题,最后给出了国家自然科学基金委员会今后在太阳能热发电领域的优先资助方向.     

Water in the upper mantle and deep crust of eastern China: concentration,distribution and implications

Understanding the concentration and distribution of water in the Earth''s mantle plays a substantial role in studying its chemical, physical and dynamic processes. After a decade of research, a comprehensive dataset of water content in upper-mantle samples has been built for eastern China, which is now the only place with water-content data from such diverse types of natural samples, and provides an integrated picture of the water content and its distribution in the upper mantle at a continental scale. The main findings include the following: (i) the temporal heterogeneity of the water content in the lithospheric mantle from early Cretaceous (∼120 Ma) to Cenozoic (<40 Ma) was tightly connected with the stability of the North China Craton (from its destruction to its consolidation); (ii) the heterogeneous water content in the Cenozoic lithospheric mantle beneath different blocks of eastern China was not only inherited from tectonic settings from which they came, but was also affected later by geological processes they experienced; (iii) the distinct water content between the lowermost crust and lithospheric mantle of eastern China and its induced rheological contrast at the base of the crust indicate that the continental crust–mantle boundary could behave either in a coupled or decoupled manner beneath different areas and/or at different stages; (iv) the alkali basalts of eastern China demonstrate a heterogeneous distribution of water content in the mantle; local and regional comparisons of the water content between the lithospheric mantle and basalts'' source indicate that the Cenozoic alkali basalts in eastern China were not sourced from the lithospheric mantle. Instead, the inferred high water contents in the mantle sources suggest that the Cenozoic eastern China basalts were likely sourced from the mantle transition zone (MTZ); and (v) both oceanic and continental crusts may carry a certain amount of water back into the deep mantle of eastern China by plate subduction. Such recycled crustal materials have not only created a local water-rich zone, but have also introduced crustal geochemical signatures into the mantle, both accounting for crustal geochemical imprints in the intra-plate magmatic rocks of eastern China.     

A quantitative study of the lithosphere and gravity anomalies along the atlantic coast

The principle of isobaric equilibrium is quantitatively applied to a strong lithosphere near a continental boundary. Following methods outlined in earlier papers, the deformation of the lithosphere near Cape Henry is determined from the magnitude and distribution of the sedimentary and fluid load superimposed on the original crystalline basement. From the calculated figure and the equivalent load, the resulting distribution of vertical stress and gravity defect are estimated. Except for the prediction of appreciable positive gravity defects at the continental shelf the calculated and observed gravity distributions are quite similar. The fibre stress due to the deformation is evaluated and it is shown that the position of the calculated maximum stress in tension on the landward side coincides with the observed position of lithospheric failure or the Fall Line. The strength in tension of the upper lithosphere here is shown to be less than 8.5 X 10⁸ dynes/cm². The simultaneous prediction of the approximate magnitudes of the gravity anomalies, their distribution and the location of the Fall line appears to show that a strong elastic lithosphere characterized by the constant b = 8.4 ± 2 × 10^?8 cm^?1 has a real and important geological existence.The investigation shows that due to the finite strength of the lithosphere, long linear areas parallel to continental coast lines are usually regions of disturbed gravity.