DISSOCIATIVE RECOMBINATION OF PROTONATED PROPIONITRILE, CH3CH2CNH+: IMPLICATIONS FOR TITAN'S UPPER ATMOSPHERE

The dissociative recombination of protonated propionitrile, CH3CH2CNH+, has been investigated at the heavy ion storage ring, CRYRING, at the Manne Siegbahn Laboratory, Stockholm University, Sweden. The thermal rate coefficient has been deduced to follow k(T) = (1.5 +/- 0.2) x 10(-6) (T/300)(-0.76) (+/-) (0.02) cm(3) s(-1) for electron temperatures ranging from similar to 10 to similar to 1000 K. Measurements of the branching fractions were performed at similar to 0 eV relative kinetic energy. It has been found that in 43% +/- 2% of the reactions the four heavy atoms remain in the same product fragment. An equal portion of the reactions leads to products where one of the heavy atoms is split off from the other three and 14% +/- 1% result in a breakup into two heavy fragments containing two heavy atoms each. We discuss the significance of the data to Titan's upper atmosphere.

Impacts of socio-economic factors on sediment yield in the Upper Yangtze River

In recent years, the role of human activities in changing sediment yield has become more apparent for the construction of hydraulic engineering and water conservation projections in the Upper Yangtze River, but it has not been evaluated at the macro scale. Taking Sichuan Province and Chongqing City as an example, this paper studies the relationship between socio-economic factors and sediment yield in the Upper Yangtze River based on section data in 1989 and 2007. The results show that sediment yield is significantly correlated with population density and cultivated area, in which the former appears to be more closely related to sediment yield. Moreover, in the relation of sediment yield vs. population density, a critical value of population density exists, below which the sediment yield increases with the increase of population density and over which the sediment yield increases with the decrease of population density. The phenomenon essentially reflects the influence of natural factors, such as topography, precipitation and soil property, and some human activities on sediment yield. The region with a higher population density than critical value is located in the east of the study area and is characterized by plains, hills and low mountains, whereas the opposite is located in the west and characterized by middle and high mountains. In the eastern region, more people live on the lands with a low slope where regional soil erosion is slight; therefore, sediment yield is negatively related with population density. In contrast, in the western region, the population tends to aggregate in the areas with abundant soil and water resources which usually lead to a higher intensity of natural erosion, and in turn, high-intensity agricultural practices in these areas may further strengthen local soil erosion. It is also found that population tends to move from the areas with bad environment and high sediment yield to the areas with more comfortable environment and less sediment yield. The natural factors have greater influence on sediment yield of western region than that of eastern region. Generally, the natural factors play a dominant role on sediment yield in the Upper Yangtze River.

Discovery of Late Cretaceous garnet two-pyroxene granulite in the southern Lhasa terrane, Tibet and its tectonic significances

The Lhasa terrane, located between the Bangonghu-Nujiang suture zone and the Indus-Yalung Tsangpo suture zone in the southern Tibetan Plateau, was considered previously as a Precambrian continental block. Mesozoic and Cenozoic tectonic evolution of the Lhasa terrane is closely related to the subduction of the Tethys ocean and the collision between the Indian and European continents; so it is one of the keys to reveal the formation and evolution of the Tibetan plateau. The garnet two-pyroxene granulite which was found at the Nyingtri rock group of the southeastern Lhasa terrene consists of garnet, clinopyroxene, orthopyroxene, labradorite, Ti-rich amphibolite and biotite, with a chemical composition of mafic rock. The metamorphic conditions were estimated to be at T = 747 similar to 834 degrees C and P = 0.90 similar to 1.35GPa, suggesting a formation depth of 45km. The zircon U-Pb dating for the garnet amphibolite and marble associated with the granulite give a metamorphic age of 85 similar to 90Ma. This granulite-facies metamorphic event together with a contemporaneous magmatism demonstrated that the southern Lhasa terrane has undergone an Andean-type orogeny at Late Mesozoic time.

Origin, development and evolutionary model of shelf desertization environment in late stage of Upper Pleistocene

Based on the study of palaeo-environmental evolution in the shelves of the Eastern China Seas, the concept of ''shelf desertization'' in the late stage of Upper Pleistocene is defined; the environmental background and evolutionary process of shelf desertization are analysed. Study on the records of subbottom profiling and the data of core samples from shelf areas revealed that during low sea-level stages, the sedimentary environment in the exposed shelf plains was dominated by aeolian depositional process under cold and dry climatic conditions, i.e. under the action of strong winter-monsoon winds. Parts of the exposed marine strata were disintegrated, and aeolian sand dunes were formed on the disintegrated marine deposits, from which the finer sediment grains were blown away by wind and deposited in the downwind areas to form the derivative loess deposits. Thus a desertization environmental system was formed in the exposed shelf plains of the Eastern China Seas.

The variation of upper ocean structure and paleoproductivity in the Kuroshio source region during the last 200 kyr

A core from the source region of the Kuroshio warm current (east of the Luzon Island) was analyzed using several proxies in order to study the variability of the Western Pacific Warm Pool (WPWP) during the last two glacial-interglacial cycles. Primary productivity (PP) variations were deduced from variations in the coccolith flora. Primary productivity was higher during glacial periods (the end of Marine Isotope Stage [MIS] 3, some periods in MIS 2 and 6), and decreased during interglacial periods (MIS 7, MIS Se and probably MIS 5c-5d), with the lowest PP in MIS 5e. variations in the delta C-13 difference in benthic and bulk carbonate, thus in the vertical gradient of delta C-13 in dissolved inorganic carbon (Delta delta C-13(c). (wuellerstorfi-N. dutertrei) and Delta delta C-13(c.) (wuellerstorfi-coccolith)) Coincided With the PP Changes, showing that export productivity was low during interglacial periods (MIS 7, MIS 5e and Holocene) and high during glacial periods (MIS 6, probably MIS 5c-5d, late MIS 4 and late MIS 3). Comparison of foraminiferal carbonate dissolution indicators and PP changes reveals that nannofossil assemblage in core Ph05-5 is not sensitive to carbonate dissolution intensity. The depth of the thermocline (DOT) was estimated from planktonic forminiferal assemblages, and was relatively greater during interglacial periods (MIS 7, MIS 5e, probably MIS 5c and Holocene) than during glacials (middle MIS 6, probably MIS 5b and 5d, some periods in MIS 4, MIS 3 and MIS 2). Good coherence between the paleoproductivity records and the DOT suggests that the DOT changes could be the primary control factor in changes of paleoproductivity, and the glacial high productivity in the Kuroshio source region could be associated with a global increase of nutrient concentration in the intermediate waters that upwelled into the photic zone. The low CO2 values derived for intervals of high productivity and a relatively shallow DOT suggest that the changes in biological productivity and DOT in the equatorial Pacific could have modified atmospheric CO2 concentrations. High Sea Surface Temperatures (SSTs) during the warm MIS 5e in combination with intensified monsoonal rain fall could have resulted in a more intense stratification of the upper waters, resulting in low nutrient supply to the surface waters and a resulting decrease in productivity. (C) 2010 Elsevier B.V. All rights reserved.

Effect of low-frequency Rossby wave on thermal structure of the upper southwestern tropical Indian Ocean

We investigate the influence of low-frequency Rossby waves on the thermal structure of the upper southwestern tropical Indian Ocean (SWTIO) using Argo profiles, satellite altimetric data, sea surface temperature, wind field data and the theory of linear vertical normal mode decomposition. Our results show that the SWTIO is generally dominated by the first baroclinic mode motion. As strong downwelling Rossby waves reach the SWTIO, the contribution of the second baroclinic mode motion in this region can be increased mainly because of the reduction in the vertical stratification of the upper layer above thermocline, and the enhancement in the vertical stratification of the lower layer under thermocline also contributes to it. The vertical displacement of each isothermal is enlarged and the thermal structure of the upper level is modulated, which is indicative of strong vertical mixing. However, the cold Rossby waves increase the vertical stratification of the upper level, restricting the variability related to the second baroclinic mode. On the other hand, during decaying phase of warm Rossby waves, Ekman upwelling and advection processes associated with the surface cyclonic wind circulation can restrain the downwelling processes, carrying the relatively colder water to the near-surface, which results in an out-of-phase phenomenon between sea surface temperature anomaly (SSTA) and sea surface height anomaly (SSHA) in the SWTIO.

Effect of Stokes drift on upper ocean mixing

Stokes drift is the main source of vertical vorticity in the ocean mixed layer. In the ways of Coriolis - Stokes forcing and Langmuir circulations, Stokes drift can substantially affect the whole mixed layer. A modified Mellor-Yamada 2.5 level turbulence closure model is used to parameterize its effect on upper ocean mixing conventionally. Results show that comparing surface heating with wave breaking, Stokes drift plays the most important role in the entire ocean mixed layer, especially in the subsurface layer. As expected, Stokes drift elevates both the dissipation rate and the turbulence energy in the upper ocean mixing. Also, influence of the surface heating, wave breaking and wind speed on Stokes drift is investigated respectively. Research shows that it is significant and important to assessing the Stokes drift into ocean mixed layer studying. The laboratory observations are supporting numerical experiments quantitatively.

GEO-ECOLOGICAL TRANSECT STUDIES IN NORTHEAST TIBET (QINGHAI, CHINA) REVEAL HUMAN-MADE MID-HOLOCENE ENVIRONMENTAL CHANGES IN THE UPPER YELLOW RIVER CATCHMENT CHANGING FOREST TO GRASSLAND

Geo-ecological transect studies in the pastures of the upper catchment of the HuangHe (99 degrees 30'-100 degrees 00'E/35 degrees 30'-35 degrees 40'N'; 3,000-4,000 in a.s.l., Qinghai province, China) revealed evidence that pastures replace forests. Plot-based vegetation records and fenced grazing exclosure experiments enabled the identification of grazing indicator plants for the first time. The mapping of vegetation patterns of pastures with isolated juniper and Spruce forests raise questions as to the origin of the grasslands, which arc widely classified as "natural" at present. Soil investigations and charcoal fragments of Juniperus (8,153 +/- 63 uncal BP) and Picea (6,665 +/- 59 uncal BP) provide evidence of the wider presence of forests. As temperatures and rainfall records undoubtedly represent a forest climate, it is assumed that the present pastures have replaced forests. Circumstantial evidence arising from investigations into the environmental history of the Holocene effectively substantiates this theory.

青藏高原及邻区面波频散反演--岩石圈-软流层体系结构研究

The Qinghai-Tibet Plateau lies in the place of the continent-continent collision between Indian and Eurasian plates. Because of their interaction the shallow and deep structures are very complicated. The force system forming the tectonic patterns and driving tectonic movements is effected together by the deep part of the lithosphere and the asthenosphere. It is important to study the 3-D velocity structures, the spheres and layers structures, material properties and states of the lithosphere and the asthenosphere for getting knowledge of their formation and evolution, dynamic process, layers coupling and exchange of material and energy. Based on the Rayleigh wave dispersion theory, we study the 3-D velocity structures, the depths of interfaces and thicknesses of different layers, including the crust, the lithosphere and the asthenosphere, the lithosphere-asthenosphere system in the Qinghai-Tibet Plateau and its adjacent areas. The following tasks include: (1)The digital seismic records of 221 seismic events have been collected, whose magnitudes are larger than 5.0 over the Qinghai-Tibet Plateau and its adjacent areas. These records come from 31 digital seismic stations of GSN , CDSN、NCDSN and part of Indian stations. After making instrument response calibration and filtering, group velocities of fundamental mode of Rayleigh waves are measured using the frequency-time analysis (FTAN) to get the observed dispersions. Furthermore, we strike cluster average for those similar ray paths. Finally, 819 dispersion curves (8-150s) are ready for dispersion inversion. (2)From these dispersion curves, pure dispersion data in 2°×2° cells of the areas (18°N-42°N, 70°E-106°E) are calculated by using function expansion method, proposed by Yanovskaya. The average initial model has been constructed by taking account of global AK135 model along with geodetic, geological, geophysical, receiving function and wide-angle reflection data. Then, initial S-wave velocity structures of the crust and upper mantle in the research areas have been obtained by using linear inversion (SVD) method. (3)Taking the results of the linear inversion as the initial model, we simultaneously invert the S wave velocities and thicknesses by using non-linear inversion (improved Simulated Annealing algorithm). Moreover, during the temperature dropping the variable-scale models are used. Comparing with the linear results, the spheres and layers by the non-linear inversion can be recognized better from the velocity value and offset. (4)The Moho discontinuity and top interface of the asthenosphere are recognized from the velocity value and offset of the layers. The thicknesses of the crust, lithosphere and asthenosphere are gained. These thicknesses are helpful to studying the structural differentia between the Qinghai-Tibet Plateau and its adjacent areas and among geologic units of the plateau. The results of the inversion will provide deep geophysical evidences for studying deep dynamical mechanism and exploring metal mineral resource and oil and gas resources. The following conclusions are reached by the distributions of the S wave velocities and thicknesses of the crust, lithosphere and asthenosphere, combining with previous researches. (1)The crust is very thick in the Qinghai-Tibet Plateau, varying from 60 km to 80 km. The lithospheric thickness in the Qinghai-Tibet Plateau is thinner (130-160 km) than its adjacent areas. Its asthenosphere is relatively thicker, varies from 150 km to 230 km, and the thickest area lies in the western Qiangtang. India located in south of Main Boundary thrust has a thinner crust (32-38 km), a thicker lithosphere of about 190 km and a rather thin asthenosphere of only 60 km. Sichuan and Tarim basins have the crust thickness less than 50km. Their lithospheres are thicker than the Qinghai-Tibet Plateau, and their asthenospheres are thinner. (2)The S-wave velocity variation pattern in the lithosphere-asthenosphere system has band-belted distribution along east-westward. These variations correlate with geology structures sketched by sutures and major faults. These sutures include Main Boundary thrust (MBT), Yarlung-Zangbo River suture (YZS), Bangong Lake-Nujiang suture (BNS), Jinshajiang suture (JSJS), Kunlun edge suture (KL). In the velocity maps of the upper and middle crust, these sutures can be sketched. In velocity maps of 250-300 km depth, MBT, BNS and JSJS can be sketched. In maps of the crustal thickness, the lithospheric thickness and the asthenospheric thickness, these sutures can be still sketched. In particular, MBT can be obviously resolved in these velocity maps and thickness maps. (3)Since the collision between India and Eurasian plate, the “loss” of surface material arising from crustal shortening is caused not only by crustal thickening but also by lateral extrusion material. The source of lateral extrusion lies in the Qiangtang block. These materials extrude along the JSJS and BNS with both rotation and dispersion in Daguaiwan. Finally, it extends toward southeast direction. (4)There is the crust-mantle transition zone of no distinct velocity jump in the lithosphere beneath the Qiangtang Terrane. It has thinner lithosphere and developed thicker asthenosphere. It implies that the crust-mantle transition zone of partial melting is connected with the developed asthenosphere. The underplating of asthenosphere may thin the lithosphere. This buoyancy might be the main mechanism and deep dynamics of the uplift of the Qinghai-Tibet hinterland. At the same time, the transport of hot material with low velocity intrudes into the upper mantle and the lower crust along cracks and faults forming the crust-mantle transition zone.

边坡工程的极限分析上限法

Theory of limit analysis include upper bound theorem and lower bound theorem. To deal with slope stability analysis by limit analysis is to approximate the real solution from upper limit and lower limit. The most used method of limit analysis is upper bound theorem, therefore it is often applied to slope engineering in many cases. Although upper bound approach of limit analysis can keep away from vague constitutive relation and complex stress analyses, it also can obtain rigorous result. Assuming the critical surface is circular slip surface, two kinematically admissible velocity fields for perpendicular slice method and radial slice method can be established according to the limit analysis of upper bound theorem. By means of virtual work rate equation and strength reduction method, the upper-bound solution of limit analysis for homogeneous soil slope can be obtained. A log-spiral rotational failure mechanism for homogeneous slope is discussed from two different conditions which represent the position of shear crack passing the toe and below the toe. In the dissertition, the author also establishes a rotational failure mechanics with combination of different logarithmic spiral arcs. Furthermore, the calculation formula of upper bound solution for inhomogeneous soil slope stability problem can be deduced based on the upper bound approach of rigid elements. Through calculating the external work rate caused by soil nail, anti-slide pile, geotechnological grid and retaining wall, the upper bound solution of safety factor of soil nail structure slope, slip resistance of anti-slide pile, critical height of reinforced soil slope and active earth pressure of retaining wall can be obtained by upper bound limit analysis method. Taking accumulated body slope as subject investigated, with study on the limit analysis method to calculate slope safety factor, the kinematically admissible velocity fields of perpendicular slice method for slope with broken slip surface is proposed. Through calculating not only the energy dissipation rate produced in the broken slip surfaces and the vertical velocity discontinuity, but also the work rate produced by self-weight and external load, the upper bound solution of slope with broken slip surface is deduced. As a case study, the slope stability of the Sanmashan landslide in the area of the Three Gorges reservoir is analyzed. Based on the theory of limit analysis, the upper bound solution for rock slope with planar failure surface is obtained. By means of virtual work-rate equation, energy dissipation caused by dislocation of thin-layer and terrane can be calculated; furthermore, the formulas of safety factor for upper bound approach of limit analysis can be deduced. In the end, a new computational model of stability analysis for anchored rock slope is presented after taking into consideration the supporting effect of rock-bolts, the action of seismic force and fissure water pressure. By using the model, not only the external woke-rate done by self-weight, seismic force, fissure water pressure and anchorage force but also the internal energy dissipation produced in the slip surface and structural planes can be totally calculated. According to the condition of virtual work rate equation in limit state, the formula of safety factor for upper bound limit analysis can be deduced.

印度与欧亚板块强烈相互作用区深部结构特征研究

The central-south Tibet is a part of the products of the continental plate collision between Eurasia and India. To study the deep structure of the study area is significant for understanding the dynamics of the continental-continental collision. A 3-D density model matched well with the observations in the central-south Tibet was proposed in this study. In addition, this study has also used numerical simulation method to prove that Quasi-Love (QL) wave is deduced by anisotropy variation but not by lateral heterogeneity. Meanwhile, anisotropy variation in the upper mantle of the Qiangtang terrane and Lhasa terrane is detected by the QL waves observed in recorded seismograms. Based on the gravity modeling, some results are summarized as follows: 1) Under the constrain of geometrical structure detected by seismic data, a 3-D density model and Moho interface are proposed by gravity inversion of the central-south Tibet. 2) The fact that the lower crustal densities are smaller than 3.2 g/cm3, suggests absence of eclogite or partial eclogitization due to delamination under the central-south Tibet. 3) Seismicity will be strong or weak in the most negative Bouguer gravity anomaly. So there is no a certain relationship between seismicity and Bouguer gravity anomaly. 4) Crustal composition are determined after temperature-pressure calibration of seismic P wave velocity. The composition of lower crust might be one or a mixture of: 1. amphibolite and greenschist facies basalt beneath the Qiangtang terrane; 2. gabbro-norite-troctolite and mafic granulite beneath the Lhasa terrane. Because the composition of the middle crust cannot be well constrained by the above data set, the data set published by Rudnick & Fountain (1995) is used for comparison. It indicated the composition of the middle crust is granulite facies and might be pelitic gneisses.Granulite facies used to be interpreted as residues of partial melting, which coincidences with the previous study on partial melting middle crust. Amphibolite facies are thought to be produced after delamination, when underplating works in the rebound of the lower crust and lithospheric mantle. From the seismology study, I have made several followed conclusions: 1) Through the numerical simulation experiment of surface wave propagating in heterogeneity media, we can find that amplitude and polarization of surface wave only change a little when considering heterogeneity. Furthermore, it is proved that QL waves, generated by surface wave scattering, are caused by lateral variation of anisotropy but not by heterogeneity. 2) QL waves are utilized to determine the variation of uppermost mantle anisotropy of the Tibetan plateau. QL waves are identified from the seismograms of the selected paths recorded by the CAD station. The location of azimuth anisotropy gradient is estimated from the group velocities of Rayleigh wave, Love wave and QL wave. It suggests that south-north lateral variation of azimuthal anisotropy locates in Tanggula mountain, and east-west lateral variation in the north of Gandese mountain with 85°E longitude and near the Jinsha river fault with 85°E longitude.

荣成基底片麻岩原岩岩石成因及其构造意义

Extensive high to ultrahigh pressure metamorphic rocks are outcropped in the the Dabie-Sulu UHP orogenic belt. Disputes still exist about for protolith nature of metamorphic rocks, petrogenesis, tectonic setting, and influence on upper mantle during the Triassic deep subduction. In this study, a combined study of petrology, geochemistry, isotope geochemistry and zircon chronology was accomplished for high-grade gneisses in the basement of the ultrahigh-pressure metamorphic Rongcheng terrane to reveal protolith nature and petrogenesis of the gneisses and to disucss the magmatic succession along the northern margin of the Yangtze block in Neoproterozoic. Gneisses in the Rongcheng terrane are characterized by negative Nb, Ta, P and Ti anomalies, relatively low Sr/Y ratios and relatively high Ba/La, Ba/Nb and Ba/Zr ratios, mostly displaying geochemical affinity to Phanerozoic volcanic arc. Neoproterozoic protolith ages (0.7 ~ 0.8 Ga) and Paleoproterozoic average crustal residence time (1.92 ~ 2.21 Ga) favour a Yangtze affinity. The gneisses mostly display characteristics of enrichment of LREE, flat heavy rare earth elements (REE) patterns, moderately fractionation between LREE and HREE and slight negative or positive Eu anomalies, probably reflecting that melting took place in the middle to low crust (26 ~ 33 km), where amphibole fractionated from the melts and/or inherited from source material as major mineral phases in the source area. Sr-Nd isotopic composition of the gneisses supports this conclusion. According to εNd(t) and εHf(t) values, the gneisses can be divided into three groups. Gneisses of group I have the highest εNd(t) and εHf(t) values, corresponding to the range of -6 ~ -3 and -2.9 ~ 13.4, respectively. This suggests obvious influx of depleted mantle or juvenile crust in the formation of protoliths. Gneisses of group II have medium εNd(t) (-9 ~ -7) and εHf(t) values (-15.8 ~ -1.4), corresponding to relatively high TDM2(Nd) (1.99 ~ 2.31 Ga) and TDM2(Hf) (1.76 ~ 2.67 Ga) , respectively. This suggests these gneisses were formed by partial melting of Paleoproterozoic crust. Gneisses of group III have the lowest εNd(t) (-15 ~ -10) and εHf(t) values (-15.8 ~ -1.4), corresponding to the largest TDM2(Nd) (1.99 ~ 2.31 Ga) and TDM2(Hf) ( 1.76 ~ 2.67 Ga), respectively. This indicates that gneisses of group III were formed by remelting of Archean crustal material and further demonstrates existence of an Archean basement probably of the Yangtze affinity beneath the Rongcheng terrane. Gneisses of three groups have also certain different geochemical characteristics. Contents of REEs and trace elements reduce gradually from group I to group III. Zirconium saturation temperatures also show similar tendency. Compared to gneisses of group II and group III, gneisses of group I display geochemical feature similar to extensional tectonic setting, having relatively little influence by the source area. Therefore, geochemical characteristics for gneisses of group I can indictate that the protoliths of the Rongcheng gneisses formed in an extensional rifting tectonic setting. This conclusion is supported by the results of eclogites and gabbros previously reported in the Dabie-Sulu orogenic belt. Statistical results of the protolith ages of the Rongcheng gneisses show two age peaks around ~728 Ma and ~783 Ma with an about 50 Ma gap. Extensive magatism in abou 750 Ma along the northern margin of the Yangtze block can hardly be observed in the Rongcheng terrane. This phenomenon likely suggests discontinuous Neoproterozoic magmatism along the northern margin of the Yangtze block.

博兴洼陷西部砂体成因与油气成藏研究

Based on achievements of thirty years of hydrocarbon exploration, this paper uses the modern theories and methods of sedimentology and oil accumulation to study the origin and distribution features of four sandbodies of Gaoqing, Fanjia, Zhenglizhuang and Jinjia from the third member to the lower second member of Shahejie Formation in detail. Various geophysical methods are also used to explain and to predict the spatial distribution of sandbodies, which further shows mechanism and the model of oil accumulation and illuminates the disciplinarians of oil enrichment and its controlling factors in the study area. The most favourable oil pools predicted by this paper have significant economic and social benefits, which has been confirmed by the exploration. The main conclusions and knowledge includes: (1) Resolving the problems, which remain unresolvable for a long time in the western area of Boxing depression, about the original environment and the spatial distribution of sandbodies of Gaoqing, Fanjia, Zhenglizhuang and Jinjia, and illuminating their relationships. It is suggested that two deltas or delta-related sandbody sediments, which include the delta sandbodies of Jinjia and Gaoqing and their frontal turbidite fan sandbody, are developed in the second and third members of Shahejie Formation. The sandbodies of Fanjia, Gaoqing and Zhenglizhuang are components of Gaoqing delta and belong to the sediments of various periods in different part of the delta. Whereas, the sandbody of Jinjia belong to the Jinjia delta or fan-delta created by the uplift of the Western Shandong and in some areas shows the features of juxtaposition, superimposed deposition and fingeration with the sandbodies of Gaoqing and Zhenglizhuang. (2)Proposing that the sandbodies of different origins in the deltas of Gaoqing and Jinjia have obvious different reservoir qualities, among which the delta frontal bedded sandbodies in the second member of Shahejie Formation in Zhenglizhuang are the best ones and the turbidite sandbody of Fanjia is relatively worse. This shows the direction of further reservoir prediction. (3) According to modern petroleum system theory and continental pool-formation theory, the author divided the western area of Boxing depression into the Jinjia—Zhenglizhuang—Fanjia nose structure belt pool-formation system and the Gaoqing fracture belt pool-formation system. The study area is predominantly located in the former belt and subdivided into pool-formation sub-systems of Zhenglizhuang-Fanjia and Jinjia, which have the source rock of mudstone and oil shale from the upper forth member and the third member of Shahejie Formation in Boxing depression. The hydrocarbon migration and accumulation are controlled by Jinjia-Zhenglizhuang-fanjia nose structure and Gaoqing fracture. (4)Proposing that compared with the best developed sandbodies and traps in the west area of Boxing, the source from the Boxing depression is not sufficient, which is the fundamental reason that the hydrocarbon resources in mid-west area is less than in the east of Boxing. (5) Under the direction of the new theory (fluid compartments theory) and new method of modern pool-formation mechanism, two kinds of pool-formation model are established in study, i.e. inner-compartment model and outer-compartment model. The former has abnormal pressure and is the antigenic source seal pool-forming mechanism, whereas the latter has normal pressure and is of the allochthonous source opening pool-formation mechanism. (6)The study shows that the four sandbodies of Gaoqing, Fanjia, Jinjia and Zhenglizhuang sand are all very benefit for pool-formation, among which the Fanjia sandbody is the best favourable one and is likely to form lithological reservoir and fault-lithological reservoir. But the main step of exploration in Gaoqing, Zhenglizhuang sandbodies should be finding out the fault block, reversed roof and stratum-lithological oil reservoir. (7)Established a set of guidelines and techniques for the research and exploration in the large scale of sandbodies. Proposing that the various traps related to reversed fault and basin-ward fault should be found in step slopes and gentle slopes respectively, and the lithological oil reservoir should mainly be found in the sandstone updip pinch out. It is also suggested that Fanjia sandbody is most favourable to form the lithological and fault-lithological and the Gaoqing, Zhenglizhuang and Jinjia sandbodies have the potential of forming fault block, reversed roof and stratum-lithological oil reservoir. (8) Interpretation and prediction the spatial distribution of main sandbodies based on various geophysical methods suggestion that Fanxi, Gao28 south and Gao27 east have better exploration potential.

青藏高原东部电性结构特征及地球动力学意义

As the largest and highest plateau on the Earth, the Tibetan Plateau has been a key location for understanding the processes of mountain building and plateau formation during India-Asia continent-continent collision. As the front-end of the collision, the geological structure of eastern Tibetan Plateau is very complex. It is ideal as a natural laboratory for investigating the formation and evolution of the Tibetan Plateau. Institute of Geophysics, Chinese Academy of Sciences (CAS) carried out MT survey from XiaZayii to Qingshuihe in the east part of the plateau in 1998. After error analysis and distortion analysis, the Non-linear Conjugate Gradient inversion(NLCG), Rapid Relaxation Inversin (RRI) and 2D OCCAM Inversion algorithms were used to invert the data. The three models obtained from 3 algorithms provided similar electrical structure and the NLCG model fit the observed data better than the other two models. According to the analysis of skin depth, the exploration depth of MT in Tibet is much more shallow than in stable continent. For example, the Schmucker depth at period 100s is less than 50km in Tibet, but more than 100km in Canadian Shield. There is a high conductivity layer at the depth of several kilometers beneath middle Qiangtang terrane, and almost 30 kilometers beneath northern Qiangtang terrane. The sensitivity analysis of the data predicates that the depth and resistivity of the crustal high conductivity layer are reliable. The MT results provide a high conductivity layer at 20~40km depth, where the seismic data show a low velocity zone. The experiments show that the rock will dehydrate and partially melt in the relative temperature and pressure. Fluids originated from dehydration and partial melting will seriously change rheological characteristics of rock. Therefore, This layer with low velocity and high conductivity layer in the crust is a weak layer. There is a low velocity path at the depth of 90-110 km beneath southeastern Tibetan Plateau and adjacent areas from seismology results. The analysis on the temperature and rheological property of the lithosphere show that the low velocity path is also weak. GPS measurements and the numerical simulation of the crust-mantle deformation show that the movement rate is different for different terranes. The regional strike derived from decomposition analysis for different frequency band and seismic anisotropy indicate that the crust and upper mantle move separately instead of as a whole. There are material flow in the eastern and southeastern Tibetan Plateau. Therefore, the faults, the crustal and upper mantle weak layers are three different boundaries for relatively movement. Those results support the "two layer wedge plates" geodynamic model on Tibetan formation and evolution.