淮北煤田宿临矿区现今地温场分布特征及其影响因素

淮北煤田是我国华东地区最主要的能源供给基地之一,研究其现今地温场特征既是强烈的现实要求,也具有十分重要的理论意义.本文在淮北煤田宿临矿区区域地质研究的基础上,根据位于宿临矿区内不同构造单元中的8个主要煤矿井田及其邻近区域111个钻孔的测温数据,绘制了矿区现今地温\|深度关系图、现今地温梯度\|深度关系图以及不同构造单元的现今地温梯度分布图,分析了宿临矿区现今地温场的分布特征.研究表明,宿临矿区现今地温梯度分布范围介于1.50～3.80 ℃/hm,整个矿区平均现今地温梯度约为2.65 ℃/hm,与华北其他主要能源盆地相比有所差异.宿临矿区现今地温梯度在相同构造单元内分布具有褶皱隆起区高、断裂密集区域高的特点;不同构造单元中井田的平均现今地温梯度相比较则表现出由东部构造单元至西部构造单元逐步增高的趋势.分析表明,区内现今地温场主要受构造格局和岩性变化影响.     

Variations of heat flow and Pn - velocity in the continental area of China

Temperature is an important factor affecting seismic velocity, and terrestrial heat flow is the most direct indication of temperature distribution of the lithosphere. Some authors therefore suggested that Pn velocity should be inversely related with heat flow. The average heat flow values (q) and Pn velocities (V _Pn) in 22 areas have been calculated and collected from published literatures to investigate the possible correlation between these two parameters for the continental area of China. However, the results show that the variations ofq andV _Pn in the studied areas are far away from the expected inverse relation. The effects of pressure of seismic velocity and contribution of crustal radiogenic heat on heat flow have been taken into consideration in regressions respectively and simultaneously. However, all the corrections are of little help for the improvement of the expected inverse relation. The conclusion deduced from the present study is that in a large scale region with complex tectonic evolution history and complex deep structure framework such as the continental area of China, temperature at the Moho boundary is not the most important factor affecting Pn velocity. The conceptual inverse correlation between heat flow and Pn velocity might be masked by various “noises”. The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,14, 42–50, 1992.     

川东南焦石坝页岩气区现今地温场特征

四川盆地是我国重要的含油气区,关于盆地现今地温场的工作,前人已经做过一些研究.而对于近年来页岩气勘探取得突破性进展的川东南焦石坝地区,现今地温场的研究工作甚少.本文基于川东南高陡褶皱带焦石坝页岩气区新增的3口钻井的稳态测温数据和118块岩石样品热导率数据,计算了研究区的地温梯度和大地热流值.结合前人的研究成果,编制了研究区大地热流等值线图.结果表明,焦石坝页岩气区地温梯度介于24~34℃/km,大地热流值介于60~70 mW·m^-2之间,与川中古隆起相似,属于地温高异常区.地温高异常缘于隆起区相对高的岩石热导率引起的浅部热流的重新分配.其次,与位于研究区东侧边界的齐岳山大断裂在燕山和喜山期的构造引起的热液活动有关.焦石坝页岩气区地温高异常对页岩气的解吸附速率具有促进作用,对提高采收率具有一定意义.

     

Distribution characteristics of terrestrial heat flow density in Jiyang depression of Shengli Oilfield, East China

Terrestrialheatflowdensityistheamountofheatperunitareatransferringfromtheearthinteriortosurface,whichisanexteriorcharacteristicofthethermalandgeodynamicprocessesoccurringindeepmantle[1].Heatflow,asthemostdirectmannerofthermalprocessindeepearthandembodyingabundantinformationofgeology,geophysicsandgeodynamics,isasyntheticallythermalindexandplaysaveryimportantroleinstudyingnotonlytheactivityofcrust,thermalstructureofcrustanduppermantle,aswellasrheologicalstructureoflithosphere,butalsotheevaluation…     

江汉盆地热流史、沉积构造演化与热事件

江汉盆地是我国前新生代海相油气勘探的重要领域之一,为研究海相烃源岩的热演化史提供地热学参数,以镜质体反射率(Ro)为古温标进行热史反演,获得了盆地的热流史.印支运动以前,盆地基底热流为50～55mW/m2;晚印支－早燕山期,热流整体升高;不同构造单元达到最高古热流的时间不同,潜北断裂以北,157Ma左右达到最高古热流（～72 mW/m2）,潜北断裂以南,43 Ma左右达到最高古热流（71～76 mW/m2）;晚喜山期,热流迅速降低,盆地快速冷却.盆地热流史和沉积构造演化、岩浆活动热事件的耦合关系表现为:印支运动以前,海相盆地稳定建造阶段为统一的低热流背景,岩浆活动微弱;晚印支－早燕山期,构造活动性增强产生深部热搅动,热流整体升高;中燕山期挤压改造变形阶段热流值的高低受控于岩浆活动热事件的分区表现,盆地基底热流表现为北降南升;晚燕山－早喜山期,陆相伸展盆地建造与叠加改造阶段,岩浆活动热事件的区域特征决定热背景分区;晚喜山期,盆地萎缩,为热流值降低的冷却过程.     

南海北部陆坡深水区的海底原位热流测量

海底热流数据是开展海洋地球动力学研究和油气资源评价的基础数据.南海北部陆坡深水区蕴含有丰富的油气和水合物资源,而该区热流站位很少.为了解陆坡深水区水合物有利区块的地热特征,利用剑鱼1型海底原位热流探针,在南海西沙海域和神狐海域成功获得了16个站位的热流值.测量结果表明,西沙海槽与白云凹陷都具有较高的热流值,西沙海槽区除1个站位结果不可信外,另2个站位所测海底表层地温梯度分别为105.3 和99.9℃·km-1,原位热流分别为89±1和87±1 mW·m-2;白云凹陷中部区域13个站位测得表层地温梯度变化于58.5~100.7 ℃·km-1,热流值除4个站位低于70 mW·m-2外,其余都变化于75±2~101±4 mW·m-2范围,比前人在白云凹陷东部获得的热流高.分析认为,西沙海槽和白云凹陷区域的高地热特征与陆坡深水区的高热背景、晚期断裂发育、底辟、岩浆侵入和热流体活动等有关.     

查干凹陷大地热流

查干凹陷是银根—额济纳旗盆地最具勘探潜力的凹陷, 但是查干凹陷及整个银根—额济纳旗盆地的大地热流研究仍为空白, 严重制约该盆地的油气资源的评价. 本文通过测试19口井107块岩芯的岩石热导率和岩石热导率原位校正, 利用协和平均公式计算得到查干凹陷各地层的岩石热导率大小; 并利用9口井的温度数据, 结合岩石热导率数据对查干凹陷的地温梯度和大地热流进行了计算. 研究结果表明查干凹陷具有构造稳定区和构造活动区之间的中温型地温场特征, 其平均地温梯度和大地热流分别为33.6℃/km, 74.5 mW/m2. 本文的研究成果为查干凹陷及银根—额济纳旗盆地油气资源评价提供地热参数.     

Heat flow in the Basin and Range province and thermal effects of tectonic extension

In regions of tectonic extension, vertical convective transport of heat in the lithosphere is inevitable. The resulting departure of lithosphere temperature and thickness from conduction-model estimates depends upon the mechanical mode of extension and upon how rapidly extension is (and has been) taking place. Present knowledge of these processes is insufficient to provide adequate constraints on thermal models. The high and variable regional heat flow and the intense local heat discharge at volcanic centers in the Basin and Range province of the United States could be accounted for by regional and local variations in extensional strain rate without invoking anomalous conductive heat flow from the asthenosphere. Anomalous surface heat flow typical of the province could be generated by distributed extension at average rates of about 1/2 to 1%/m.y., similar to rates estimated from structural evidence. To account for higher heat flow in subregions like the Battle mountain High, these rates would be increased by a factor of about 3, and locally at active bimodal volcanic centers, by an order of magnitude more.     

准噶尔盆地大地热流特征与岩石圈热结构

沉积盆地现今大地热流和岩石圈热结构特征是岩石圈构造-热演化过程的综合反映和盆地热史恢复的约束条件,对盆地动力学研究和油气资源评价具有重要意义.作者系统分析了准噶尔盆地2000年以来新增的102口钻孔的系统测井温度和400余口钻孔的试油温度资料,采用光学扫描法测试了15口钻孔共187块代表性岩石热导率,首次建立了准噶尔盆地岩石热导率柱,新增了11个高质量的(A类)大地热流数据,分析了准噶尔盆地大地热流分布特征,并揭示了其岩石圈热结构.研究表明,准噶尔盆地现今地温梯度介于 11.6~27.6℃/km,平均21.3±3.7℃/km,大地热流介于23.4~56.1 mW/m2,平均42.5±7.4 mW/m2,表现为低地温梯度、低大地热流的"冷"盆特征.准噶尔盆地大地热流与地温梯度分布规律基本一致,主要受控于基底的构造形态,东部隆起最高,陆梁隆起次之,乌伦古坳陷、中央坳陷和西部隆起较低,北天山山前坳陷最低.准噶尔盆地地壳热流介于18.8~26.0 mW/m2,地幔热流介于16.5~23.7 mW/m2,壳幔热流比值介于0.79~1.58,属于典型的"冷壳冷幔"型热结构.准噶尔盆地地幔热流值与莫霍面起伏一致,隆起区地幔热流高,坳陷区地幔热流低.     

我国陆区地壳生热率分布与壳幔热流特征研究

壳幔热流配分代表了一个地区的深部热量来源与最基础的地热背景,为区域地热资源的形成提供了重要的约束条件.本文依托CRUST1.0模型与地质资料,将中国陆区在平面上划分为19个构造区,在垂向上将这些区域从第四系沉积物至上地幔的地层划分为8个圈层,确定了这些圈层的分布范围和厚度.在全国范围内实测放射性生热率数据664组,收集地壳放射性生热率及U、Th、K元素含量数据约1000组,系统地完成了上述区域各圈层的放射性生热率填图,统计得出我国陆区上、中、下地壳生热率的平均值分别为1.31 μW·m^-3、0.57 μW·m^-3与0.22 μW·m^-3.在此基础上,结合最新的全国大地热流测量数据（1503组）完成了我国陆区地壳-地幔热流分布的研究.研究结果表明,我国陆区q_c/q_m>1的面积占80.1%、q_c/q_m>1.2的面积占65.8%.除我国东部、中部的一些盆地之外,在我国陆区大部分地区,地壳均为大地热流的最主要热源.地壳各圈层中,基底层至中地壳为地壳的主要的产热区域,贡献了平均约50%的大地热流值.本文以面积加权计算得我国陆区地壳热流平均值为39.1 mW·m^-2,其中青藏高原最高、东南沿海次之,两者分别得益于较大的地壳厚度与较高的基岩地层生热率.我国陆区地幔热流平均值为29.7 mW·m^-2,与全球地幔热流平均值接近,其中东部沿海地区、环鄂尔多斯地区、藏滇地热带分布区较高.地壳热流、地幔热流的高值区与我国的主要地热资源分布区均具有较好的一致性.

     

Controls on migration and aggregation for tectonically sensitive elements in tectonically deformed coal: An example from the Haizi mine,Huaibei coalfield,China

Tectonically deformed coal(TDC)develops because of the superimposed deformation and metamorphism of a coal seam by tectonic movements.The migration and accumulation of trace elements in TDC is largely in response to stress-strain conditions.To develop a law governing the migration and aggregation of sensitive elements and investigate the geological controls on TDC,coal samples from different deformation sequences were collected from the Haizi mine,in the Huaibei coalfield in Anhui Province,China,and the concentrations of 49 elements were determined by XRF and ICP-MS,and then microscopically analyzed.The results show that the distribution and morphology of minerals in coal is related to the deformation degree of TDC.The evolutionary process runs from orderly distribution of minerals in a weak brittle deformed coal to disordered distributions in ductile deformed coal.According to the elemental distribution characteristics in TDC,four types of element migration can be identified:stable,aggregate,declining,and undulate types,which are closely related to the deformation degree of TDC.Present data indicate that the overall distribution of rare earth elements(REE)does not change with metamorphism and deformation,but it shows obvious dynamic differentiation phenomena along with the deformation of TDC.Tectonic action after coal-formation,brittle or ductile deformation,and the metamorphic mechanism and its accompanying dynamic thermal effects are the main factors that influence the redistribution of elements in TDC.We conclude that tectonic movements provide the motivation and basis for the redistribution of elements and the paths and modes of element migration are controlled by brittle and ductile deformation metamorphic processes.The dynamic thermal effect has the most significant effect on coal metamorphism and tectonic-stress-accelerated element migration and accumulation.These factors then induce the tectonic-dynamic differentiation phenomenon of element migration.     

南海三维热岩石圈结构及地表构造响应

为系统了解南海海底热流特征和岩石圈热结构与地表构造的关系,本文首先以最新海底热流为约束,采用三维数值模拟方法计算得到整个南海的"热"岩石圈底部边界（底界）的埋深,然后开展详细分析壳、幔热流贡献以及岩石圈热结构与地表不同构造单元之间的对应关系.结果显示南海岩石圈底部边界埋深为30~100 km,最浅埋深集中分布在南海海盆水深大于3000 m的区域（如南海西北次海盆、西南次海盆和东部次海盆西侧）,以及南海北部陆缘中部、莺歌海盆地、中建南盆地和南薇西盆地,体现了南海深部结构对地表不同构造单元的控制作用;靠近海盆东侧的马尼拉海沟具有较低的海底热流,对应岩石圈底界埋藏也较深,可能与南海和古南海洋壳俯冲有关;吕宋岛弧（119°E-122°E和13°N-17°N）表现出较高的海底热流,同时具有较浅的热岩石圈底界埋深,可能与南海板块和菲律宾海板块双向俯冲有关.     

Sap flow of Artemisia ordosica and the influence of environmental factors in a revegetated desert area: Tengger Desert,China

Artemisia ordosica is considered as an excellent sand‐fixing plant in revegetated desert areas, which plays a pertinent role in stabilizing the mobile dunes and sustaining the desert ecosystems. Stem sap flows of about 10‐year‐old Artemisia ordosica plants were monitored continuously with heat balance method for the entire growing season in order to understand the water requirement and the effects of environmental factors on its transpiration and growth. Environment factors such as solar radiation, air temperatures, relative humidity, wind speed and precipitation were measured by the eddy covariance. Diurnal and seasonal variations of sap flow rate with different stem diameters and their correlation with meteorological factors and reference evapotranspiration were analysed. At the daily time scale, there was a significantly linear relationship between sap flow rate and reference evapotranspiration with a correlation coefficient of R² = 0·6368. But at the hourly time scale, the relationship of measured sap flow rate and calculated reference evapotranspiration (ET₀) was affected by the precipitation. A small precipitation would increase the sap flow and the ET₀; however, when the precipitation is large, the sap flow and ET₀ decrease. Leaf area index had a coincident variation with soil water content; both were determined by the precipitation, and meteorological factors were the most significant factors that affected the sap flow of Artemisia ordosica in the following order: solar radiation > vapour pressure deficit > relative humidity > air temperature > wind speed. The close correlation between daily sap flow rate and meteorological factors in the whole growing season would provide us an accurate estimation of the transpiration of Artemisia ordosica and rational water‐carrying capacity of sand dunes in the revegetated desert areas. Copyright © 2010 John Wiley & Sons, Ltd.     

Present geotemperature and its suggestion to natural gas generation in Xujiaweizi fault-depression of the northern Songliao Basin

According to stastistic of present geotemperatures at the depths of 1000,2000,3000 and 4000 m,respectively in the Xujiaweizi fault-depression of the north Songliao Basin,the result indicates that Xujiaweizi fault-depression falls in the high geotemperature area,with the higher geothermal gradient in the depression layer than that in the fault-depression layer.The geothermal gradient decreases with the increasing of the depth.The thermal conductivity of rock greatly controls the geothermal gradient.The main factors constraining the current geotemperature include thermal configuration of the earth's crust, deep faults,distribution and abundance of radioelements.The high geotemperature is in favour of generation of deep gas.     

Fluid flow and mineralization of Youjiang Basin in the Yunnan-Guizhou-Guangxi area, China

Comprehensive studies, based on isotope geochemistry of C, H, O, S and Sr, chronology, common element and trace element geochemistry of fluid inclusions for the epithermal Au, As, Sb and Hg deposits in the Youjiang Basin and its peripheral areas, suggested that the ore fluid was the basin fluid with abundant metallic elements and the large-scale fluid flow of the same source in the late Yenshan stage was responsible for huge epithermal mineralization and silicification. The ore fluid flowed from the basin to the platform between the basin and the platform and migrated from the inter-platform basin to the isolated platform in the Youjiang Basin. The synsedimentary faults and paleokast surface acted respectively as main conduits for vertical and lateral fluid flow.     

Tectonic thermal history and its significance on the formation of oil and gas accumulation and mineral deposit in Ordos Basin

The analyzing data on stratigraphic temperature measurement , thermal conductivity of the strata and radioactive heat production rate show that the present average geothermal gradient in the Ordos Basin is 2.93℃/100 m, and the average heat flow value is 61.78 mW/m2, which belongs to the mesothermal basin, and the value of the present geothermal gradient and heat flow in the east is higher than that in the west. The sandstone radioactive heat production rate of Zhiluo Group in Dongsheng Uranium deposits of Yimeng uplift is obviously higher in the mudstone, indicating that there exists a uranium anomaly. Based on studies of the present thermal field of the basin, the late-Mesozoic paleotemperature and paleogeothermal gradient are determined by using different kinds of paleotemperature methods. According to the anomaly of the late-Mesozoic paleotemperature gradient and magmatic event age, there was a tectonic thermal event in the early Cretaceous epoch of late-Mesozoic. This article rebuilds tectonic thermal history of different tectonic units by thermal history simulation using basin simulating software. The evolution of oil-gas and coal, and accumulation (mineralization) of mineral uranium are all controlled by the tectonic thermal history in the Ordos basin, especially by the tectonic thermal event that happened in the late Mesozoic. For both the gas source rocks of upper Paleozoic group and lower paleozoic group, the gas was largely generated in the early Cretaceous epoch of the late Mesozoic. The main petroleum generation period for Yanchang Group in Triassic system is the early Cretaceous epoch too, and the highest thermal maturity of the coal of Permo-Carboniferous, Triassic, and Jurassic reaches is the early Cretaceous epoch also. Early Cretaceous epoch is still one of the most important mineralizing periods of uranium.     

共和盆地恰卜恰地热区现今地热特征

恰卜恰地热区位于青海共和盆地的东北部,是我国重要的具有干热岩地热资源勘探开发潜力的地区之一.自2013年起,不同的研究者针对该区开展了大量地球物理探测工作,然而现今地热场的研究相对较少.本文基于4口干热岩钻孔的稳态测温资料和81块岩芯样品的热导率测试数据,计算了研究区4个大地热流值.研究结果表明：研究区基底花岗岩层现今地温梯度为39.0~45.2℃·km^-1,平均值为41.3℃·km^-1,大地热流值介于93.3~111.0 mW·m^-2之间,平均值为102.2 mW·m^-2,与我国主要的克拉通型盆地（如柴达木盆地、四川盆地和鄂尔多斯盆地）和新生代裂谷型盆地（如渤海湾盆地）相比,该区属于青藏高原高热流背景下的局部异常高地温梯度和高大地热流区.分析认为,研究区高地热异常可能暗示共和盆地浅部（20 km以浅）存在局部异常热源体（岩浆囊）.

     

Temperature and Pressure Dependencies of Thermal Transport Properties of Rocks: Implications for Uncertainties in Thermal Lithosphere Models and new Laboratory Measurements of High-Grade Rocks in the Central Fennoscandian Shield

Measurements on thermal conductivity and diffusivity as functions of temperature (up to 1150 K) and pressure (up to 1000 MPa) are presented for Archaean and Proterozoic mafic high-grade rocks metamorphosed in middle and lower crustal pressures, and situated in eastern Finland, central Fennoscandian Shield. Decrease of 12–20% in conductivity and 40–55% in diffusivity was recorded between room temperature and 1150 K, which can be considered as typical of phonon conductivity. Radiative heat transfer effects were not detected in these samples. Pressure dependencies of the samples are weak if compared to crystalline rocks in general, but relatively typical for mafic rocks.The temperature and pressure dependencies of thermal transport properties (data from literature and the present study) were applied in an uncertainty analysis of lithospheric conductive thermal modellings with random (Monte Carlo) simulations using a 4-layer model representative of shield lithosphere. Model parameters were varied according to predetermined probability functions and standard deviations were calculated for lithospheric temperature and heat flow density after 1500 independent simulations. The results suggest that the variations (uncertainties) in calculated temperature and heat flow density values due to variations in the temperature and pressure dependencies of conductivity are minor in comparison to the effects produced by typical variations in the room temperature value of conductivity, heat production rate or lower boundary condition values.     

华南陆缘高热流区的壳幔温度结构与动力学背景

华南陆缘是我国重要的矿产、地热资源区.晚中生代以来,在太平洋板块西向俯冲,地幔热对流活动共同作用下,该区出现多期岩浆-热事件和大规模爆发式成矿作用.在前人研究基础上,本文利用地表热流观测资料、地震剪切波资料、重力位球谐系数,计算了壳-幔温度结构,分析了动力学背景.计算结果表明：华南陆缘东南沿海地带,地壳10 km以浅温度达200℃以上,居里点温度475℃,莫霍面平均温度550℃.地壳浅层较热,花岗岩中放射性元素衰变放热是地壳浅层地下水热活动的重要热源,但地壳总体温度不高,为"冷壳热幔"型热结构.地幔中,90 km深度,温度950~1250℃;120 km深度,温度1050~1400℃;150 km深度,温度1200~1450℃;220 km深度,温度1500~1700℃."热"岩石圈底界深度在110~150 km之间,西深东浅.岩石圈内,地幔应力场为挤压-伸展相间格局;岩石圈之下,地幔应力场为一个以南昌为中心、长轴NE-SW向的椭圆.分析认为,晚中生代以来,太平洋板块的西向俯冲,导致华南陆缘在区域性SE向地幔对流背景上叠加局域性不稳定热扰动,在175~85Ma期间,上地幔物质向上流动,形成不同的岩浆活动高峰期.同时,岩石圈地幔受俯冲洋壳流体的影响,含水量高,黏度小,在地幔流切向应力场作用下,岩石圈底界由西向东"波浪"状减薄.现今岩石圈之下仍具备地幔小尺度热对流温度条件,但除地表浅层外,地壳整体温度不高,岩石圈构造稳定.     

南海北部大陆边缘盆地地热特征与油气富集

本文报道了莺歌海盆地、北部湾盆地共148个新测热导率数据,根据收集的钻井温度数据新增计算65个大地热流数据;结合前人研究成果绘制了南海北部大陆边缘沉积盆地的地温梯度图、大地热流分布图;系统归纳了南海北部大陆边缘油气勘探成果.结果表明,南海北部大陆边缘珠江口盆地、琼东南盆地、北部湾盆地、莺歌海盆地的平均热流值分别为68.7±11 mW/m2、71.1±13 mW/m2、65.7±8.9 mW/m2、74.7±10 mW/m2,属于典型的“热盆”.热流区域分布特征总体上受大地构造背景控制,随地壳厚度从北向南,由陆架到陆坡区逐渐减薄而增高,水热活动与岩浆活动等是引起局部高热流异常的原因.盆地地温场的差异控制和约束了油气分布富集规律,从研究区油气勘探成果中可以发现,该区域的气田多发育于高热流盆地（凹陷）,而中-低热流盆地（凹陷）则多孕育油田,油气田具有“北油南气”的分布特征.