Abstract:The Yixian Formation becomes world well-known by fancy Jehol bita fossils,each signify headway of bita research would bring both here and abroad scientists' attention.As a result of deuteric tectonic destroy and weathering effect,the Jehol bita's palaeogeograpic and basin sedimentary characteristics are hard to make detailed field works and nethermore research.This systematic field sedimentary indicates that 6 sedimentary strata of Yixian formation formed in different phases of passive continental margin to foreland basin evolving process,depositional environment attributes to alluvial fan-braided channel-meander-lacustrine system.From lower Laogonggou stratum up to Jingangshan one,the sedimentary environment was continuously changed.The lithofacies and rock sets was frequently replaced.The sedimentary clast abundantly supply,so the basin was rapidly filled in.The full sedimentary history could be divided into channel and lacustrine types.Fluvial facies possesses main body of early period,each basin tectonic cycle begins in alluvial-channel facies,they are affected by region geologic,geographic and climatic diversities,then develop into freshwater and saltwater lacustrine environments.In Filling moment,basins of predominating fluvial facies consists of alluvial fan sets,flood plain sets and lakeshore plain-delta sets.Lacustrine sediment models make up of logged-depth and brackish water(gypsiferous)types.

Abstract:对山东兖州东滩补33孔(地理坐标北纬35°27'19"、东经116°51'32")采取孢粉样品并进行了分析,从太原组到下石盒子组都有大量孢粉化石,经分析鉴定和统计,共发现孢粉化石55属155种及部分未定种。根据孢粉属种的纵向分布规律及含量的变化,建立了本区早二叠世3个孢粉组合,自上而下为:.Florinites-Punctatisporites组合(428.36～369.10m);.Punctatisporites-Sinulatisporites组合(543.43～496.95m);.Thymospora pseudothiessenii-T.thiessenii组合(589.20～550m)。本孔孢粉组合与华北地区的孢粉组合以及其他地区的孢粉组合进行对比,由于华北地区石炭系—二叠系界线与国际接轨,移至Pseudoschwagerina带之底,因此,孢粉组合时代分别为早二叠世早期、早二叠世中期、早二叠世晚期。最后,结合层序地层划分分析了古气候变化。

Abstract:Biogenic gas is the product of methanogen in anaoxic environment.Its formation and occurrence is controlled by the distribution of methanogen.The present method in studying the distribution of methanogen is MPN(numbers of methanogen).Because methanogen is strict with its environment,especially with the occurrence of oxygen,trivial change should disturb the bacterial collects and make the number different from the reality.Otherwise,collection of the fresh groundwater is difficult for us.All those make MPN turn to be hard to be dealed with.The concentration of some special biomarkers of methanogen,especially its core membrane components,could reflect the distribution of methanogen for a time.This method is simple and easy to operate,could make up the deficiency.In this paper,the distribution of archaeol,the core membrane structure components,is analyzed in the sediment from two wells in the Sanhu depression Qaidam basin.The results showed a good relationship between methanogen and salinity.In high salt area,the activity of methanogens was depressed in the shallow(above 1000m),and then turned to active up to 2000m.While in the surrounding area like Sebei 1 area,the salinity of sediment is much lower,the depression of methanogen in the shallow is slight that make methanogen mainly concentrate above 1000m and is low below 1000m.In the final,combined with the sediment palaeoenvironment and salinity of the sediment,the activation of methanogen in Sanhu depression is characterized.

Abstract:Talas-Ferghana fault(TF)is is a major right-lateral strike-slip fault in the central Asia.One unresolved issue is the its southward extension and propagation across the Tarim basin.Based on remote sensing geology,field observation and and geophysical survey,it is suggested that the Cenozoic TF terminated in the Kashi depression(KD)by minor dextral strike-slip faults.The dextral shearing along TF is accommodated by thrusting systems at its eastern block,which resulted in contrasting structures on the both sides of TF in the western Tarim basin.The Kashi depression located between the Pamir and TF is a foreland basin filled by thick Cenozoic molasses sequence.With the northward thrusting of Pamir,a series of E-W to NW folds and thrusting faults developed in the Mesozoic to Cenozoic sequences.With the blocking of Bachu uplift,the dextral shearing with TF is transfered into horizontal shortening along Keping thrust belt to the east.Regional tectonic analysis indicates that the northward thrusting of Pamir plateau has reactivated TF in the Late Cenozoic,with dextral shearing and structural transferring.As a result,The pamir show asymmetric structural pattern on its both sides.

Abstract:Correlation between Tongbai and western Dabie orogenic belts has been discussed based on available data that suggest the Tongbai and western Dabie orogenic belts can be devided into 7 and 10 structural units,respectively.The north five units of the two orogenic belts can be correlated and resumed as the Paleozoic active continental margin of the North China plate,indicating both the Tongbai and western Dabie suffered a Paleozoic subduction of Yangtze plate.To the south,The Xiongdian ecologite in the Xiongdian-Huwan ductile shear zone implies the occurrence of the Paleozoic HP metamorphism.However it is difficult to recognize the exact distributing range and tectonic unit of the HP metamorphism.Whereas the other Mesozoic HP-UHP rocks occurred in belt-shaped and dome-shaped occupy the major part of the Mesozoic orogenic belt in Tongbai and western Dabie areas,forming the line and dome structural units that can be correlated each other.Because the frameworks of both the Tongbai and western Dabie are composed of the Paleozoic arc-continent collision orogenic belt in the north part and the Mesozoic orogenic belt formed by uplift of the HP-UHP rocks in the south part,both of them are characterized by the multiple Paleozoic and Mesozoic orogenic belt.In view of structural units and tectonic evolution,both of them are be correlated each other.

Abstract:The formation and evolution of landslips were closely to regional and local tectonics in the Yangtze Three Gorges Reservoir.Appearance of landslips were controlled by regional tectonic evolution and by local tectonic reform later also.The first,landslips were properly formed as a result of deformation of reverse structure controlled by thin structure.The second,fissure system and the Yangtze direction controlled the landslips formation and scale.The third,landslips appeared mostly in the compound place of structure in different times.The fourth,the formation and evolution of the landslips controlled by Neotectonic stress field are not casual,different development stages and different distribution types in time and place of landslips result from earth crust unbalance rising,sliding direction and breaking strength of landslips result from earth crust horizontal moving,and showed mainly on compound of Neotectonic stress field and superimposing gravity stress field.

Abstract:On the basis of actual analytical data of 767 composite samples collected mainly from about 750 large to middle representative granitoid bodies in China,the average chemical compositions and element abundances of about 70 chemical elements of SiO_2,Al_2O_3,Fe_2O_3,FeO,MgO,CaO,Na_2O,K_2O,H_2O ,CO_2,TFe_2O_3,Ag,As,Au,B,Ba,Be,Bi,Cd,Cl,Co,Cr,Cs,Cu,F,Ga,Ge,Hf,Hg,Li,Mn,Mo,Nb,Ni,P,Pb,Rb,S,Sb,Sc,Se,Sn,Sr,Ta,Th,Ti,Tl,U,V,W,Zn,Zr,La,Ce,Pr,Nd,Sm,Eu,Gd,Tb,Dy,Ho,Er,Tm,Yb,Lu and Y in alkalifeldspar granite,syenogranite and adamellite in 7 geotectonic units of China such as the Tianshan-Xingan orogenic series,Sino-Korean metaplatform,Kunlun-Qilian-Qinling orogenic series,Yunnan-Tibet orogenic series,Yangtze metaplatform,South China-Youjiang orogenic zone and Himalayan orogenic zone,are calculated and presented in this paper.It is sufficiently discussed on the characteristics of petrochemical parameters,trace element contents and rare earth element distributions of different rock types of granitoids in different geotectonic units.

Abstract:藏南江孜—哲古一带广泛分布有北西向和近东西向产出的基性—中基性岩墙群,它们是新特提斯洋晚期发生大规模扩张的产物。本文对这些基性岩脉进行了较为系统的元素地球化学和Pb-Sr-Nd同位素研究。元素地球化学研究表明,该岩体略为富集LREE,Eu的亏损不明显,表明岩浆结晶分异作用较弱;LILE的富集和HFSE的亏损均不明显,所有样品均以相对富集Ta、Ce和亏损La、Y和Yb为特点。铅同位素206Pb/204Pb比值和207Pb/204Pb比值变化范围较小,分别为18.330～18.717和15.504～15.674;而208Pb/204Pb值和μ值相对变化较大,分别为37.664～39.156和9.296～9.931;初始87Sr/86Sr值变化范围较大,为0.7044～0.7105;岩石的εNd(t)值变化范围为-4.49～ 6.77,绝大多数为正值。微量元素地球化学和Nd-Sr-Pb同位素研究结果表明,藏南地区基性岩墙群可能是由来自亏损地幔源的岩浆与来自富集地幔源(EM)的岩浆混合的产物,其快速侵位造成岩浆分异作用较差,而岩浆的不均匀混合导致LILE富集与HFSE亏损均不明显,并产生较大的初始87Sr/86Sr比值变化范围。藏南基性岩墙群的研究结果表明了青藏高原地区复杂的地幔结构特征,这也为研究该区的地幔演化积累了丰富的资料。

Abstract:甘肃马衔山侵入杂岩体位于祁连造山带的东部,侵入于新太古代—古元古代变质基底岩系(马衔山岩群)中,主体岩石类型为片麻状二长花岗岩,其次为侵入于片麻状二长花岗岩中的钾长花岗岩。利用LA-ICPMS(激光剥蚀等离子体质谱)测年设备,对片麻状二长花岗岩进行单颗粒锆石微区U-Pb同位素测定,获得1192±38Ma的年龄,为中元古代晚期;岩石地球化学特征显示二长花岗岩侵入体具有火山弧-同碰撞花岗岩特征。马衔山变形侵入体所代表的热—构造事件与格林威尔造山运动时代(1190～980Ma)相当,可能与Rodinia超大陆形成有一定的成因联系。这一新的资料,对研究祁连造山带元古宙大地构造格局、构造演化及中国大陆动力学具有重要意义。

Abstract:甘肃天水东岔镇一带出露的宽坪岩群位于北祁连—北秦岭—华北板块交界地带,呈残留体状分布于花岗岩之中,主体为一套低角闪岩相变质的片麻岩、片岩夹斜长角闪岩。利用西北大学大陆动力学重点实验室LA-ICP-MS(激光剥蚀等离子体质谱)方法,对其中的斜长角闪岩进行单颗粒锆石微区U-Pb同位素测定,获得1753±14Ma的上交点年龄,为古元古代晚期;并反映出415±2Ma～383±2Ma的变质年龄信息。结合前人研究成果,认为区域上宽坪岩群主体形成年龄为中元古代,而研究区的宽坪岩群形成于古元古代,受到加里东晚期和华力西早期构造—热事件的改造。推测研究区的宽坪岩群可能属于华北古老基底南缘的组成部分。

Abstract:云南大坪金矿是哀牢山金矿带中最重要的金矿之一,主要赋存在受到强烈韧性剪切和水-岩反应的加里东期闪长岩中,是典型的韧性剪切带控矿型金矿。本文对大坪金矿绢英岩化近矿围岩中的热液绢云母进行了40Ar-39Ar定年,得到其坪年龄为33.76±0.65Ma,相应的反等时线和正等时线年龄分别为33.55±0.74Ma和33.57±0.74Ma,显示大坪属于喜马拉雅早期金矿。这些年龄数据与哀牢山金矿带中广泛出现的喜马拉雅期煌斑岩脉年龄(33～34Ma)非常接近,显示金矿与上地幔部分熔融形成的煌斑岩之间可能存在成因上的联系。喜马拉雅早期,本区在地壳拉张和强烈韧性剪切条件下,Moho面上升,地幔物质部分熔融并上涌,形成大量煌斑岩等基性岩脉,地幔排气形成的深源地幔流体和下地壳脱水形成的富CO2流体混合,沿韧性剪切带上升,并与糜棱岩化的加里东期闪长岩围岩发生水-岩反应,局部发生流体沸腾作用,导致成矿流体物理化学条件的改变和矿石矿物的沉淀,在剪切带脆性构造中形成含金石英脉。

Abstract:金宝山和白马寨铜镍硫化物矿床均主要赋存在峨眉山大火山岩省中,但其矿化特征存在许多不同。本文着重对比了金宝山铂钯矿床和白马寨铜镍矿床的铂族元素(PGE)地球化学特征,发现前者表现为高ΣPGE及低的(Cu Ni)、Pd/Ir(3.84~26.49)、Cu/Pd(46.91~1309.58)值和Au/Pd值,相反,后者表现为低ΣPGE、高(Cu Ni)、Pd/Ir(4.72~297.2)、Cu/Pd(10875.13~974788.55)值和较高的Au/Pd值。金宝山和白马寨PGE原始地幔标准化配分模式均主要表现为左倾型,但二者表现为镜像关系。金宝山较白马寨的PGE间相关性好,可能说明白马寨母岩浆经历了较为复杂的地质过程,其铂族元素体系因此受到较大的扰动。结合前人有关杨柳坪铜镍铂族元素矿床的铂族元素数据,认为峨眉地幔柱形成铜镍铂族元素矿床大致可以分成3个阶段:1金宝山阶段:即为S的低度饱和阶段,为峨嵋地幔柱上升初期,吸收少量壳源物质,由于PGE在硫化物中很高的分配系数,导致少量硫化物熔体从硅酸盐中萃取大量PGE和少量Cu-Ni熔离出来,与铬铁矿、橄榄石和辉石等,于高温下结晶分异堆积而成金宝山岩体,形成独立铂钯矿床。金宝山岩体为富含PGE硫化物熔体的主要接受者;2杨柳坪阶段:即S的中度饱和阶段,为峨嵋地幔柱上升的中期,吸收较多的壳源物质,发生较强的硫化物熔离作用,较多的Cu、Ni和PGE随硫化物熔体向下运移堆积而成杨柳坪铜镍铂族元素矿床,杨柳坪岩体为富含铂族元素硫化物熔体的次要接受者;3白马寨阶段:即S的高度饱和阶段,为峨眉地幔柱上升的后期,由于吸收大量的壳源物质,自身温度降低,发生强烈的硫化物熔离作用,大量铜镍及少量残余在硅酸盐中的PGE随硫化物熔体熔离出来堆积而成。由于PGE数量稀少,达不到工业品味,因此只能形成独立的铜镍矿床,白马寨母岩浆为铂族元素的给予者。

Abstract:Through analyzing the sedimentary dynamics in meandering stream, a model of the Xujiahe Formation parasequence in river facies was established in central Sichuan. Fining-upward and coarsening-upward parasequences occurred usually in meandering stream sediments. There was fining-upward parasequence in braided stream, but coarsening-upward parasequence was not in braided stream sediments. The fining-upward parasequence boundary of meandering stream and braided stream is the ravinement surface of river course. The coarsening-upward parasequence boundary of meandering stream was the exposure mudstone of flooding plain and root clay. By the correlation of parasequence and short-term base level cycles in river facies, they had the same time limit. The time limit was 0.01~0.05 Ma. And the boundary of them has the same lithologic character: the ravinement surface of river course or exposure mudstone of flooding plain and root clay. The sediment was of the same age in parasequence and short-term base level cycles, and it was just one thing. From different analyses, the differences of them are revealed: one is the classic sequence stratigraphy, and the other is the high-resolution sequence stratigraphy. The focus of parasequence and short-term base level cycles in river facies is that, when the base-level in meandering stream changes, the sediment relative to the stream stage gets shallow upward. The sediments in the stream stage was getting shallower to the natural levee and the flooding plain.

Abstract:Gas geochemistry, fluid inclusion salinity, core observation and thin section analysis indicate that the Permian-Triassic Changxing-Feixianguan gas reservoir experienced chemical alteration of thermochemical sulfate reduction (TSR) since the middle Yanshanian period. The TSR alteration is mainly shown in three aspects: (1) The C_ 2 and 12C relationships to CH_4 and 13C are preferentially consumed, resulting in the gas dryness coefficient to be larger and carbon isotope heavier; (2) A great deal of water produced by TSR makes the original formation water in the gas reservoir diluted, so that the salinity of formation water is reduced correspondingly; (3) TSR and its products, CO_2 and H_2S, make the dolomite and anhydrite dissolved, which increases the porosity and then improve the physical property of reservoir.

Abstract:Owing to differential erosion, the red weathering crusts of carbonate rocks usually show special profile structures that are characteristic of thick-bedded, intensely weathered profiles and strongly undulate basement rock surface (i.e. alternate distribution of solution grooves and stone teeth). In this work a typical red weathering crust of dolomite rock (i.e. Pingba profile) is selected in a karst terrace in Guizhou Province, China. Via field geology, geochemistry, mineralogy, grain size analyses, and in comparison with two neighboring limestone soils (i.e. Luoli profile and Longdongbao profile) as well, we discussed the formation process of the red weathering crusts of carbonate rocks, and demonstrated that micro-area transportation of acid-insoluble residues of carbonate rocks is a style of forming the red weathering crusts, especially the thick-bedded those of carbonate rocks. The weathering crusts at solution grooves, at the scope of the depth upwards from weathering front, are in-situ weathering residues (i.e. residual layers); over this depth upwards, are accumulated deposits of different weathering intensity (i.e. accumulation layers) from upper adjacent stone teeth situation by micro-area transportation. This process is a direct cause leading to intense undulation of weathering indices with the depth. The latter generally compose the principal part of the profiles. At solution grooves, the chronostratigraphy of the red weathering crusts of carbonate rocks shows that, at residual layers, upwards from weathering front, the weathering age is from new to old; at accumulation layers, from bottom to top, the weathering age is from old to new. The weathering front is a main place of geochemical reaction, and at this limited-thick interface, with quick dissolution of carbonates, acid-insoluble residues begin to obviously decompose. However, ensuing evolvement of weathering crusts is very slow. When they is up to gravity balance (i.e. flat surface and no micro-area transportation), under the action of weathering from exterior to interior, at the scope of the depth from the surface downwards, the weathering profiles are gradually reconstructed and take on the developing feature of normal weathering crusts.

Abstract:利用中法1995年布设在跨过阿尔金断裂剖面上的18个流动三分量地震台站记录到的近5个月的天然地震记录,经筛选得到533个高质量接收函数。通过速度分析和接收函数成像处理,得到了阿尔金断裂附近地壳结构的清晰图像。塔里木盆地的Moho界面非常清楚,近水平地位于~44km深度上。该界面以低缓的角度一直向南延伸到了阿尔金断裂附近的~70km的深度。阿尔金断裂以南柴达木盆地下面的Moho界面也十分清楚,近水平地位于~55km的深度上,在阿尔金断裂附近存在向上挠曲,并抬升到了~45km的深度上。在阿尔金断裂下方,Moho界面存在~15km的错断。塔里木盆地Moho之下还存在另一个震相,我们解释为沉积层多次波与可能来自Hales间断面转换波的复合震相。接收函数成像结果表明阿尔金断裂是一个超壳的岩石圈断裂,具有比较直立的产状和很狭窄的剪切变形带。根据这些结果,我们推测塔里木的下地壳可能要比柴达木的下地壳更硬,柴达木地壳增厚的原因可以部分归结于它有一个相对弱的下地壳,青藏高原隆升没有扩展到塔里木盆地是因为塔里木盆地具有更刚性的下地壳和岩石圈地幔。高原北部地壳变形应该是所谓青藏高原隆升的“硬”变形模式(Tapponnieretal.,2001)和“软”变形模式(EnglandandHouseman,1989;ClarkandRoyden,2000)共同作用的结果。