Abstract:A new oviraptorid dinosaur Jiangxisaurus ganzhouensis gen. et sp. nov., is erected based on a partial skeleton from the Upper Cretaceous Nanxiong Formation of Ganzhou City, Jiangxi Province. The new taxon differs from other oviraptorids in the weakly downturned rostrum of the lower jaw, much-elongated mandible with a height-to-length ratio being about 20% and the length ratio of radius to humerus of about 0.70. This species not only adds a new member to oviraptorid dinosaurs, but also provides more information about oviraptorid paleogeographical distribution in southern China.

Abstract:As a more efficient quantitative method for morphological analysis, geometric morphometrics is applied to the flabellate fossils Flabellophyton including Flabellophyton lantianensis and Flabellophyton strigata from Neoproterozoic Ediacaran Lantian biota, South China. Both traditional morphometric analysis (including diverging angle, length, and width distribution) and geometric morphometric analysis [including superposition of normalized area analysis, non-metric multidimensional scaling (n-MDS), Bray-Curtis similarity cluster analysis (CLUSTER) and analysis of similarities (ANOSIM)] were performed. The results indicate there are great interspecific morphological differences between F. lantianensis and F. strigata, in addition to some intraspecific variations within each species. Here we preliminarily suggest that the previously defined Flabellophyton should be subdivided into 2 genera at least: one marked by the dark transverse striated structure, and the other without. This recharacterization and reclassification work still needs further careful observation and comprehensive analysis with large number of flabellate fossils combining morphology, structure, population, and community-ecology study.

Abstract:The abundant fossils of early angiosperms found in the Yixian Formation (125 Ma, Early Cretaceous) have demonstrated unexpectedly high diversity and various reproductive strategies, and thus have shed new light on early angiosperm evolution. Here, using light microscope and scanning electron microscope, we document several fructifications of Baicarpus gen. nov. from Liaoning province, China. Each fructification of the new taxon includes several apocarpous carpels/fruits attached in an urn-formed gynobase. Each fruit/carpel has a persistent straight style and an ovary enclosing a single seed. These fossil plants demonstrate a new floral organization and thus enhance our understanding of the diversity of angiosperms in the Yixian Formation. Together with previously reported ones, this fossil angiosperm suggests an origin time for angiosperms earlier than widely accepted.

Abstract:Biostratigraphic analysis is an essential element for understanding global tectonics and the evolution of life on Earth. Quantitative analysis of sedimentary sequences provides the precise age constraints on timing of significant events in Earth’s history. This paper presents results from quantitative stratigraphic analysis of Upper Cretaceous Tethyan Himalayan sequences. This analysis resulted in a new composite stratigraphic section for the Cretaceous strata of Tibet (TIBETKCS). The eight Upper Cretaceous sections were analyzed in this study and 12 planktonic foraminifera zones were recognized based on available data. Quantitative measurements were made using a Graphic Correlation with Graphcor 3.0 software and correlated to the world standard Cretaceous Composite Section (MIDKCS). The sections were also examined using Constrained Optimization software by CONOP9. Level Penalty was applied as the rule to measure misfit among automatically correlated sections. The new TIBETKCS correlates well with planktonic foraminifera ages from previous work in southern Tibet. A fitting equation of y=?0.19x+305 with a correlation coefficient of 0.94 was obtained from this work. The ages of the first and last appearances of 64 planktonic foraminifera can be calculated with this equation with ± 0.3 Ma precision. This level of precision is approximately 10 times higher than age determinations with traditional methods. Two extinction events were resolved within this analysis at ~93.5 Ma and ~85.5 Ma corresponding to the Ocean Anoxic Events at Cenomanian–Turonian and Coniacian–Santonian boundaries respectively.

Abstract:The Yishu fault zone (mid-segment of the Tanlu fault zone) was formed in the Presinian. Periodic tectonic activities and strong seismic events have occurred along the fault zone. During the initial stage of the Caledonian Movement, with the proceeding of the marine transgression from the Yishu paleo-channel to the western Shandong, uneven thick sediments, composed mainly of sand, mud and carbonates of littoral, lagoon, and neritic facies, were deposited in the Yishu fault zone and western Shandong, and constructed the bottom part of the Lower Cambrian consisting of the Liguan and Zhushadong formations. Through field observations and the lab-examinations, various paleoseismic records have been discovered in the Liguan Formation and the Zhushadong Formations of the Yishu fault zone and its vicinity, including some layers with syn-sedimentary deformation structures that were triggered by strong earthquakes (i.e. seismite, seismo-olistostrome, and seismo-turbidite). Paleoseismic records developed in the Zhushadong Formation are mainly seismites with soft-sediment deformation structures, such as liquefied diapir, small liquefied-carbonate lime-mud volcano, liquefied vein, liquefied breccia, convolute deformation (seismic fold), graded fault, soft siliceous vein, and deformation stromatolite, as well as seismites with brittle deformation structures of semiconsolidated sediments. Paleoseismic records preserved in the Liguan Formation are not only seismo-olistostrome with a slump fold, load structure, and ball-and-pillows, but also seismo-turbidite with convolution bedding, graded bedding and wavy-bedding. However, in the western Shandong area, the closer to the Yishu fault zone, the greater the thickness of the Liguan Formation and the Zhushadong Formation, the greater the number and type of layers with paleoseismic records, and the higher the earthquake intensity reflected by associations of seismic records. This evidence indicates that tectonic taphrogenesis accompanied by strong earthquake events occurred in the Yishu fault zone during the initial stage of the Caledonian Movement, which embodied the break-up of the Sino-Korean Plate along the Paleo-Tanlu fault zone at that time.

Abstract:Multistage deformation events have occurred in the northeastern Jiangshao Fault (Suture) Belt. The earliest two are ductile deformation events. The first is the ca. 820 Ma top-to-the-northwest ductile thrusting, which directly resulted from the collision between the Cathaysia Old Land and the Chencai Arc (?) during the Late Neoproterozoic, and the Jiangnan Orogenic Belt that formed as the ocean closed between the Yangtze Plate and the jointed Cathaysia Old Land and the Chencai Arc due to continuous compression. The second is the ductile left-lateral strike-slipping that occurred in the latest Early Paleozoic. Since the Jinning period, all deformation events represent the reactivation or inversion of intraplate structures due to the collisions between the North China and Yangtze plates during the Triassic and between the Philippine Sea and Eurasian plates during the Cenozoic. In the Triassic, brittle right-lateral strike-slipping and subsequent top-to-the south thrusting occurred along the whole northeastern Jiangshao Fault Zone because of the collision between the North China and Yangtze plates. In the Late Mesozoic, regional extension took place across southeastern China. In the Cenozoic, the collision between the Philippine Sea and Eurasian plates resulted in brittle thrusts along the whole Jiangnan Old land in the Miocene. The Jiangshao Fault Belt is a weak zone in the crust with long history, and its reactivation is one of important characteristics of the deformation in South China; however, late-stage deformation events did not occur beyond the Jiangnan Old Land and most of them are parallel to the strike of the Old Land, which is similar to the Cenozoic deformation in Central Asia. In addition, the Jiangnan old Land is not a collisional boundary between the Yangtze Plate and Cathaysia Old Land in the Triassic.

Abstract:Intervals of soft-sediment deformation structures are well-exposed in Jurassic lacustrine deposits in the western Qaidamu basin. Through field observation, many soft-sediment deformation structures can be identified, such as convoluted bedding, liquefied sand veins, load and flame structures, slump structures and sliding-overlapping structures. Based on their genesis, soft-sediment deformation structures can be classified as three types: seismic induced structures, vertical loading structures, and horizontal shear structures. Based on their geometry and genesis analysis, they are seismic-induced structures. According to the characteristics of convoluted bedding structures and liquefied sand veins, it can be inferred that there were earthquakes greater than magnitude 6 in the study area during the middle Jurassic. Furthermore, the study of the slump structures and sliding-overlapping structures indicates that there was a southeastern slope during the middle Jurassic. Since the distance from the study area to the Altyn Mountain and the Altyn fault is no more than 10km, it can be also inferred that the Altyn Mountain existed then and that the Altyn strike-slip fault was active during the middle Jurassic.

Abstract:The Yunmeng Shan metamorphic core complex (MCC) is composed of the lower plate, the upper plate and the detachment zone. The detachment zone consists of ductile shear zone (mylonite zone), chloritized microbreccias zone and the brittle fault plane. The ductile shear zone contains mylonitic rocks, protomylonites, and mylonites. Finite strain measurements of feldspar porphyroclasts from those rocks using the Rf/φ method show that the strain intensities increase from mylonitic rocks (Es=0.66–0.72) to protomylonites (Es=0.66–0.83), and to mylonites (Es=0.71–1.2). The strain type is close to flatten strain. Kinematic vorticity estimated by Polar Mohr diagrams suggest that foliations and lineation of mylonite (0.47

Abstract:Late Cambrian to Early Ordovician sedimentary rocks in the western Tarim Basin, Northwest China, are composed of shallow-marine platform carbonates. The Keping Uplift is located in the northwest region of this basin. On the basis of petrographic and geochemical features, four matrix replacement dolomites and one type of cement dolomite are identified. Matrix replacement dolomites include (1) micritic dolomites (MD1); (2) fine–coarse euhedral floating dolomites (MD2); (3) fine–coarse euhedral dolomites (MD3); and (4) medium–very coarse anhedral mosaic dolomites (MD4). Dolomite cement occurs in minor amounts as coarse saddle dolomite cement (CD1) that mostly fills vugs and fractures in the matrix dolomites. These matrix dolomites have δ18O values of ?9.7‰ to ?3.0‰ VPDB (Vienna Pee Dee Belemnite); δ13C values of ?0.8‰ to 3.5‰ VPDB; 87Sr/86Sr ratios of 0.708516 to 0.709643; Sr concentrations of 50 to 257 ppm; Fe contents of 425 to 16878 ppm; and Mn contents of 28 to 144 ppm. Petrographic and geochemical data suggest that the matrix replacement dolomites were likely formed by normal and evaporative seawater in early stages prior to chemical compaction at shallow burial depths. Compared with matrix dolomites, dolomite cement yields lower δ18O values (?12.9‰ to ?9.1‰ VPDB); slightly lower δ13C values (?1.6‰–0.6‰ VPDB); higher 87Sr/86Sr ratios (0.709165–0.709764); and high homogenization temperature (Th) values (98°C–225°C) and salinities (6 wt%–24 wt% NaCl equivalent). Limited data from dolomite cement shows a low Sr concentration (58.6 ppm) and high Fe and Mn contents (1233 and 1250 ppm, respectively). These data imply that the dolomite cement precipitated from higher temperature hydrothermal salinity fluids. These fluids could be related to widespread igneous activities in the Tarim Basin occurring during Permian time when the host dolostones were deeply buried. Faults likely acted as important conduits that channeled dolomitizing fluids from the underlying strata into the basal carbonates, leading to intense dolomitization. Therefore, dolomitization, in the Keping Uplift area is likely related to evaporated seawater via seepage reflux in addition to burial processes and hydrothermal fluids.

Abstract:The Aghajari Formation, called also the Upper Fars, develops throughout the Folded Zagros Zone and its thickness in the type section in southwest of Iran is 2966 meters. To analyze the sedimentary basin of this Formation, lithofacies, architectural elements and petrofacies of the related deposits in a section in southeast of Sarvestan in Fars Province of Iran with a thickness of 2221.45 meters were examined. Microscopically studying thin sections, the petrography and the occurrence of the deposits were determined. In this section, 16 lithofacies, 10 architectural elements and 2 sandstone petrofacies were identified. The lithofacies were divided into two major and minor groups, in which the major lithofacies consist of coarse-grained (Gh, Gp, Gt and Gm), medium-grained (Sh, Sp, St, Sl, Sm, Sr and Ss and fine-grained ones (Fm, Fl and Fsm), and the minor lithofacies were evaporative and mixed silisiclastic-carbonate. The identified architectural elements are CH, SB, GB, LA, DA, CR, CS, LV, LS, CH (FF) and FF. By combining evidences from facies analysis and architectural elements together, the Aghajari Formation was divided into three parts in which the related sedimentation environments, from top to bottom, are gravel, gravel-sand and fine-grained meandering river respectively. There have also been playas and shoreface in the lower part. Based on petrography, the sandstones of this formation were classified into two groups: litharenite and sublitharenite. The origin of these deposits (sandstones) was appointed to the recycled orogeny and the source of quartz is low and medium to high metamorphic rank. Using the field evidences, the paleocurrent direction was achieved indicating the direction of the paleocurrent from northwest to southeast at the time of deposition. It is hoped that these data can be used in the interpretation of the basin and reconstruction of the paleogeography in the local and regional scales.

Abstract:The Kooh-Shah region located in a Tertiary volcanic–plutonic belt of the Lut Block in eastern Iran comprises several subvolcanic intermediate to acidic intrusive rocks, diorite to syenite in composition, which have intruded into volcanic rocks. The Kooh-Shah granitoid rocks are characterized by enrichment in large ion-lithophile elements (LILE: e.g. Sr, Ba, Rb) and depletion in high field-strength elements (HFSE: e.g. Nb, Ta, Ti). The chondrite-normalized REE patterns are characterized by moderate LREE enrichment (La/Yb)N=6.01–10.01, medium-heavy REE enrichment, and absence of Eu anomalies. The Kooh-Shah intrusive rocks are metaluminous, shoshonitic with calc-alkaline affinity and high values of magnetic susceptibility, and classified as the magnetite-series of oxidant I-type granitoids. The age of Kooh-Shah granitoid rocks based on zircon U–Pb age dating is 39.7±0.7 Ma (=Middle Eocene) and the ranges of their initial 87Sr/86Sr and 143Nd/144Nd ratios are from 0.704812 to 0.704920 and 0.512579 to 0.512644, respectively, when recalculated to an age of 39 Ma. The initial ?Nd isotope values for the Kooh-Shah intrusive rocks range from -0.18 to 1.09. This geochemical data indicates that the Kooh-Shah granitoid rocks formed from depleted mantle in an island arc setting. The geochemical signature of the studied granitoid rocks represents a characteristic guide for future exploration of copper-gold porphyry-type deposits in the Lut block.

Abstract:U-Pb zircon age, geochemical, and Sr-Nd-Pb isotopic data of mafic dykes from eastern Shandong Province, eastern China is reported herein. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) U-Pb zircon analyses of two samples from the investigated mafic dykes yield consistent ages ranging from 121.9 Ma ± 0.47 Ma to 122.9 Ma ± 0.61 Ma. The mafic dykes are characterized by high (87Sr/86Sr) i ranging from 0.7087 to 0.7089, low εNd(t) values ranging from -16.9 to -17.8, 206Pb/204Pb = 17.15 to 17.17, 207Pb/204Pb = 15.45 to 15.47, and 208Pb/204Pb = 37.59 to 37.68. Results from the current study suggest that the mafic dykes are derived from partial melting of ancient lithospheric mantle that was variably hybridized by melts derived from foundered lower crustal eclogite. The mafic dykes may have been generated through subsequent insignificant crystal fractionation and very minor crustal contamination during magma ascent. Combined with previous studies, the current findings provide new evidence that the intense lithospheric thinning beneath the eastern Shandong Province of eastern China occurred at ~120 Ma, and that this condition was caused by the removal of the lower lithosphere (mantle and lower crust).

Abstract:Petrographical and geochemical methods were combined to investigate the provenance, geodynamic and weathering history of the Shurijeh sandstones, Kopet-Dagh Basin. The point-counting method and XRF technique are used for modal and geochemical analyses. Based on petrographical examinations, it seems that the Shurijeh sandstones are mainly deposited in the craton interior and recycled orogen belts. In addition to petrographical investigation, geochemical analyses (major oxides and trace elements) of Late Jurassic-Early Cretaceous rocks reveal that the sedimentation processes are performed in a passive continental margin. Such interpretation is supported with geodynamic and paleogeographical studies of the Kopeh-Dagh basin during this time. The geochemical investigations suggested that the composition of probable source rocks mostly was acidic-intermediate with minor mafic igneous rocks. Based on the above, Paleo-Tethys remnants and their collision-related granitoids, in the south and west of Mashhad, may have been the source area for these rocks. CIA values, which range from 63.8 to 94.9 in samples, are suggesting a moderate to relatively high degree of alteration (weathering) in the source area. Therefore, petrographical and paleogeographical studies of siliciclastic rocks can be used for the provenance, tectonic setting and paleoweathering studies in the source area.

Abstract:Natural gas exploration in Nanpu sag, Bohai Bay Basin, has achieved breakthroughs in recent years, and a number of natural gas and condensate wells with high yield have been found in several structures in the beach area. Daily gas production of single wells is up to 170,000 m3, and high-yield wells are mainly distributed in?the Nanpu No. 1 structural belt.?Studies have shown that these natural gases are mainly hydrocarbon gases, with methane content about 80% to 90% and ethane 6%–9%, so they are mainly wet gas; and non-hydrocarbons are at a low level.?Carbon isotopes of methane range from –42‰ to –36‰, and ethane from –28‰ to –26‰. Calculated maturity based on the relationship between δ13C and Ro of natural gas, the gases are equivalent to those generated from organic matter when Ro is 1.0%–1.7% (mainly 1.25%–1.32%). The natural gas is oil-type gas generated from the source rocks at mature to high mature stage, associated with condensate, so carbon isotopes of the gases are heavier. Natural gas in the Nanpu No.1 structural belt is mainly associated gas with condensate. The analysis of the origin and source of natural gas and condensate, combined with the monomer hydrocarbon carbon isotopes and biomarker, indicated that the main source rocks in the Nanpu No.1 structural belt were Es3 (the lower member of the Shahejie Formation), followed by Es1 (the upper member of the Shahejie Formation).?The high-mature hydrocarbons from source rocks in the deep sag mainly migrated through deep inherited faults into shallow traps and accumulated to form oil and gas pools. Therefore, there is a great potential for exploring gas in deep layers.

Abstract:Total 138 coal samples and 14 parting samples were taken from the No. 6 Seam of the Jungar Coalfield, Inner Mongolia. These samples were analysed by optical microscopy, sequential chemical extraction procedure (SCEP), inductively coupled plasma mass spectrometry (ICP–MS), X–ray powder diffraction (XRD), and scanning electron microscope in conjunction with an energy–dispersive X–ray spectrometer (SEM–EDX) analysis. The results indicate that the Li contents have reached the industrial grade of the coal associated Li deposit, and the total Li reserves have reached 2406600 tons, that is, 5157000 tons Li2O in the No. 6 seam in the Jungar Coalfield. The sequential chemical extraction procedure results suggest that the Li concentration is mainly related to inorganic matter. The minerals in the coals consist of kaolinite, boehmite, chlorite–group mineral, quartz, calcite, pyrite, siderite and amorphous clay material. Some Li could be absorbed by clay minerals in the Li–bearing coal seam. The chlorite phase?could be?most likely the host for a part of Li. The Yinshan Oldland should be the most possible source of Li of the coal.

Abstract:The Kuqa and the Southern Junggar foreland thrust belts, which lie to the southern and northern Tianshan, respectively, were formed under a strong compressional tectonic setting. Due to the differential propagation and deformation under the control of the décollement horizon, the structural deformation styles differ in the Kuqa and Southern Junggar thrust belts. Imbricated stacking is developed in the Kuqa thrust belt, forming a piggyback imbricated pattern of faulted anticline and fault-block structural assemblage dominated by salt structures. In contrast, wedge-shaped thrusts are developed in Southern Junggar, mainly forming vertical laminated patterns of multi-wedge-structure stacks strongly influenced by the décollement horizons. The different deformation patterns and structural styles of the north and south of Tian Shan control the contrasting characteristics of hydrocarbon accumulation in the foreland thrust belts of the Kuqa and the Southern Junggar thrust belts, including the variance in the hydrocarbon trap types, pathway systems and hydrocarbon-bearing horizons. Proven by the hydrocarbon accumulation research and exploration achievements, recent exploration targets should focus on sub-salt piggyback imbricated structural patterns in the Kuqa and the deep laminated patterns in the Southern Junggar thrust belt.

Abstract:The variation of in situ stress before and after earthquakes is an issue studied by geologists. In this paper, on the basis of the fault slip dislocation model of Wenchuan Ms8.0 earthquake, the changes of co-seismic displacement and the distribution functions of stress tensor around the Longmen Shan fault zone are calculated. The results show that the co-seismic maximum surface displacement is 4.9 m in the horizontal direction and 6.5 m in the vertical direction, which is almost consistent with the on-site survey and GPS observations. The co-seismic maximum horizontal stress in the hanging wall and footwall decreased sharply as the distance from the Longmen Shan fault zone increased. However, the vertical stress and minimum horizontal stress increased in the footwall and in some areas of the hanging wall. The study of the co-seismic displacement and stress was mainly focused on the long and narrow region along the Longmen Shan fault zone, which coincides with the distribution of the earthquake aftershocks. Therefore, the co-seismic stress only affects the aftershocks, and does not affect distant faults and seismic activities. The results are almost consistent with in situ stress measurements at the two sites before and after Wenchuan Ms8.0 earthquake. Along the fault plane, the co-seismic shear stress in the dip direction is larger than that in the strike direction, which indicates that the faulting mechanism of the Longmen Shan fault zone is a dominant thrust with minor strike-slipping. The results can be used as a reference value for future studies of earthquake mechanisms.

Abstract:The Jiweishan landslide illustrates the failure pattern of an apparent dip slide of an oblique thick-bedded rockslide. Centrifugal modeling was performed using a model slope consisting of four sets of joints to investigate the landslide initiation mechanism. Crack strain gauges pasted between the slide blocks and the base failed in sequence from the rear to the front as the centrifugal acceleration increased. When the acceleration reached 16.3g, the instantaneous failure of the key block in the front triggered the apparent dip slide of all blocks. The physical modeling results and previous studies suggest that the strength reduction in the weak layer and the failure of the key block are the main reasons for the Jiweishan landslide. The centrifuge experiment validated the previously proposed driving-blocks–key-block model of apparent dip slide in oblique with inclined bedding rock slopes. In addition, the results from limit equilibrium method and centrifuge test suggest that even though the failure of the key block in the front is instantaneous, a progressive stable–unstable transition exists.

Abstract:This paper takes the South Yellow Sea as an example to show a new method for comprehensive geological-geophysical research such as residual basin and tectonolayering using airborne gravity and magnetic data in China. Based on airborne gravity and magnetic data, by measuring and analyzing stratigraphic density and susceptibility, the depths to the pre-Sinian magnetic basement top, the pre-Jurassic top and the Cenozoic bottom, are obtained by forward and inverse methods constrained by seismic and drilling data; and furthermore, the residual thicknesses of the Sinian–Triassic, the Jurassic–Cretaceous and the Cenozoic are calculated. Based on airborne gravity and magnetic anomalies, the faults in the pre-Sinian magnetic basement, the Jurassic-Cretaceous and the Cenozoic are respectively interpreted by the qualitative and quantitative methods. On the basis of the above study, and combining regional important tectonic events, four tectonolayers are divided in the vertical succession in South Yellow Sea, namely the pre-Sinian magnetic basement, the Sinian-Triassic, the Jurassic-Cretaceous and the Cenozoic. The result shows that there are thick Cenozoic and Jurassic-Cretaceous strata and thin residual Sinian-Triassic strata in the Suzhong-Huangnan depression area, but there are thin or only sporadic Mesozoic-Cenozoic terrestrial strata and thick Sinian-Triassic marine strata reserved in Subei-Huangzhong uplift area and Sunan-Wunansha uplift area. The four tectonolayers are very different in structures as well as distributions in plane.

Abstract:The Dabashan nappe structural belt links the Hannan block to the west with the Huangling block to the east between Yangxian and Xiangfan. The Dabashan arc-shaped fold belt formed during late Jurassic and was superposed on earlier Triassic folds. To achieve an improved understanding of the deep tectonics of the Dabashan nappe structural belt, we processed and interpreted the gravity and magnetic data for this area using new deep reflection seismic and other geophysical data as constraints. The results show that the Sichuan basin and Daba Mountains lie between the Longmenshan and Wulingshan gravity gradient belts. The positive magnetic anomalies around Nanchong-Tongjiang-Wanyuan-Langao and around Shizhu result from the crystalline basement. Modeling of the gravity and magnetic anomalies in the Daba Mountains and the Sichuan basin shows that the crystalline basement around Nanchong-Tongjiang-Wanyuan-Langao extends to the northeast underneath the Wafangdian fault near Ziyang. The magnetic field boundary in the Zhenba-Wanyuan-Chengkou-Zhenping area is the major boundary of the Dabashan nappe thrusting above the Sichuan Basin. This boundary might be the demarcation between the south Dabashan and the north Dabashan structural elements. The low gravity anomaly between Tongjiang and Chengkou might be partly caused by thickened lower crust. The local low gravity anomaly to the south of Chengkou-Wanyuan might result from Mesozoic strata of low density in the Dabashan foreland depression area.

Abstract:In order to study the characters of chemical kinetics for organophosphorus migration in clay with different pH, waste of organophosphorus was put under pressure to leakage permeating the cohesive soil, and simulate the process of organophosphorus leakage permeating the Aquitard, searching the characters of chemical kinetics for organophosphorus migration in clay with different pH. It is shown that the ability of migration of organophosphorus leakage permeating the cohesive soil fall with increase of pH; the penetration rate of organophosphorus is about 1.25% when pH is 7.5, organophosphorus has not penetrated the cohesive soil when pH is equal or greater than 8.5. The effect of retardarce is obvious. Concentration of PO43? that comes from the mineralization of organophosphorus is lowered slightly with increases of pH of clay, and rise with extension of time. The Chemical Kinetics equation is log c=-0.1pH+0.2172k1t+S.

Abstract:Dune fields at the northern margin of the East Asian monsoon (EAM), are mosaics of mobile and vegetation-stabilized aeolian dunes. These sand dunes are highly sensitive to environmental change, thus the distribution and the timing of their development may provide important clues to past environmental dynamics. Due to the strong wind erosion and dune migration, long and continuous stratigraphic records are seldom preserved. Synthesizing a large body of events, ultimately producing a relatively complete and high-resolution record, may be a proper method to investigate the dune development history and climate change. In this study, we synthesized a large body of luminescence ages for aeolian deposits from the Mu Us, Otindag, Horqin dune fields at the northern margin of the EAM. The results show that these dune fields, as a whole experienced a most extensive mobility during the early Holocene, followed by a widespread shift toward limited mobility and soil development in the mid-Holocene, and widespread reactivation occurred during late Holocene. The dune developments are directly linked to the effective moisture change controlled by the EAM changes, which respond to the low latitude summer insolation variation. The increased subsidence at the margin contrary to the core EAM, the delay from the feedback of the soil-vegetation-air coupled system, the increased evaporation due to the high temperature all play partial role in the lag of the margin EAM effective moisture change to the low latitude summer insolation. The asynchronous end of the wetter mid-Holocene mainly responds to the southeastwardly shift of the precipitation belt, while the regional sensitivity, response speed and internal feedback also contributed. The correspondence between dune records and North Atlantic drift-ice records of the rapid climate changes implies a close relationship between North Atlantic climate and the frequent dune activity at the northern margin of EAM.

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