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The wind-water two-phase erosion and sediment-producing processes in the middle Yellow River basin. China

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Science China Earth Sciences 2000年第2期43卷 176-186页

作者：许炯心 Institute of Geography Chinese Academy of Sciences Beijing China

Based on data from the middle Yellow River basin. a wind-water two-phase mechanism for erosion and sediment-producing processes has been found. By using this mechanism, the extremely strong erosion and sediment yield in the study area can be better explained. The operation of wind and water forces is different in different seasons within a year. During winter and spring, strong wind blows large quantities of eolian sand to gullies and river channels, which are temporally stored there. During the next summer, rainstorms cause runoff that contains much fine loessic material and acts as a powerful force to carry the previously prepared coarse material. As a result, hyperconcentrated flows occur, resulting in high-intensity erosion and sediment yield.

关键词： erosion sediment yield wind-water two-phase processes middle Yellow River basin.

Thermal-rheological structure of lithosphere beneath the northern flank of Tarim basin. western China: Implications for geodynamics

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Science China Earth Sciences 2004年第7期47卷 659-672页

作者： LIU Shaowen1, WANG Liangshu1, LI Cheng1, LI Hua1, HAN Yongbing1, JIA Chengzao2 & WEI Guoqi2 1.Department of Earth Sciences, Nanjing University,Nanjing 210093, China 2.Chinese Petroleum Exploration and Development Institution,Beijing 100083,China Department of Earth Sciences Nanjing University Nanjing China Chinese Petroleum Exploration Development Institution Beijing China

Based on the data of geo-temperature and thermophysical parameters of rocks in the Kuqa Depression and the Tabei Uplift, northern flank of the Tarim basin. in terms of the analytical solution of 1-D heat transfer equation, the thermal structure of the lithosphere under this region is determined. Our results show that the average surface heat flow of the northern flank of the Tarim basin.is 45 mW/m2, and the mantle heat flow is between 20 and 23 mW/m2; the temperature at crust-mantle boundary (Moho) ranges from 514°C to 603°C and the thermal lithosphere where the heat conduction dominates is 138–182 km thick. Furthermore, in combination with the P wave velocity structure resulting from the deep seismic sounding profile across this region and rheological modeling, we have studied the local composition of the lithosphere and its rheological profile, as well as the strength distribution. We find that the rheological stratification of the lithosphere in this region is apparent. The lowermost of the lower crust is ductile; however, the uppermost of the mantle and the upper and middle parts of the crust are both brittle layers, which is typically the so-called sandwich-like structure. Lithospheric strength is also characterized by the lateral variation, and the uplift region is stronger than the depression region. The lithospheric strength of the northern flank of the Tarim basin.decreases gradually from south to north; the Kuqa Depression has the lowest strength and the south of the Tabei Uplift is strongest. The total lithospheric strength of this region is4.77×1012–5.03×1013 N/m under extension, and 6.5×1012–9.4×1013 N/m under compression. The lithospheric brittleductile transition depth is between 20 km and 33 km. In conclusion, the lithosphere of the northern flank of the Tarim basin.is relatively cold with higher strength, so it behaves rigidly and deforms as a whole, which is also supported by the seismic activity in this region. This rigidity of the Tarim lithosphe

关键词： thermal-rheological structure of lithosphere, rheological stratification, geodynamics, Tarim basin.

The formation and evolution of Chepaizi-Mosuowan paleo-uplift and its control on the distributions of sedimentary facies in the Junggar basin

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Science China Earth Sciences 2010年第6期53卷 818-831页

作者： JI YouLiang ZHOU Yong KUANG Jun WAN Lu ZHANG Rui LU ChunHong State Key Laboratory of Petroleum Resource and Prospecting China University of PetroleumBeijing 102249China Xinjiang Oil Field Urumqi 834000China

The Chepaizi-Mosuowan paleo-uplift is a large-scale uplift stretching across the Junggar basin.formed during the Yanshanian. It has experienced four evolutionary stages: the initial forming stage (J1), the intense development stage (J2+3), the waning and burial stage (K-E), and the tilting and extinction stage (N-Q). The most intense period of activities is the Middle Jurassic. Dur-ing the Early Jurassic, the Chepaizi-Mosuowan paleo-structure was a low amplitude uplift. Because of the subsequent strong uplifting during Middle-Late Jurassic, the Middle and Upper Jurassic were eroded. With the evolution of the Chepaizi-Mosuowan paleo-uplift, the sedimentary pattern of the basin.changed, and the paleo-uplift separated the northern depositional systems from those in the south side. As a result, the basin.tectonics controlled the distribution and evolution of the depositional systems. During Early Jurassic, while the paleo-uplift was low, its controlling effect on depositional systems was limited and sediments coming from the northwest could reach the central and southern parts of the basin. With the strong uplifting of the Chepaizi-Mosuowan paleo-structure during Middle-Late Jurassic, sediments from the northwest provenance could only deposit in the northern graben of the paleo-uplift. The intense erosion of the Middle-Upper Jurassic also changed the former sedimentary center of the basin.into a source area, supplying sediments for grabens on both sides of the paleo-uplift. In the Cretaceous, regional subsidence caused the paleo-uplift to be buried again and subsequently sediments accumulated on top of it. The depositional facies are dominated by fluvial in the Early Cretaceous and shallow lacustrine to deltaic in the Late Cretaceous. In the history of the long-lasting development of this paleo-uplift, large-scale erosions of the paleohigh not only provided sufficient sediments to the center of the Junggar basin. but also created favorable conditions for the formation o

关键词： Chepaizi-Mosuowan paleo-uplift formation and evolution depositional systems Junggar basin.

Molecular structure of kerogens from source rocks of the Tarim basin. A study by Py-GC-MS and methylation-Py-GC-MS

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Science China Earth Sciences 2005年第3期48卷 313-325页

作者： JIA Wanglu PENG Ping'an State Key Laboratory of Organic Geochemistry Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou 510640 China State Key Laboratory of Organic Geochemistry Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou 510640 China

Flash pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) and in situ methylation-pyrolysis-gas chromatography-mass spectrometry (methylation-Py-GC-MS) have been employed for a study of molecular structure of kerogens from source rocks of the Tarim basin. The main products from Py-GC-MS of the Ordovician and Triassic kerogens from the Tarim basin.are n-alkanes and n-alk-1-enes which decrease in relative abundance with in- creased carbon number. The major products from methylation-Py-GC-MS are normal saturated fatty acid methyl esters which show maxima at C16 and C18. These aliphatic compounds are mainly from lipids of planktonic algae. Moreover, there are more abundant long-chain fatty acids (C20-C26) and normal n-alkanes and n-alk-1-enes (C15-C25) in pyrolysates of Triassic kerogens than that of Ordovician kerogens, reflecting the discrepancies in sources of the Triassic kerogens and the Ordovician kerogens. Besides these aliphatic compounds, methoxyl benzoic acid methyl esters were detected only in products from methylation-Py-GC-MS of late Ordovician kerogen TAC1-1, which possibly was the first molecular evidence for the appearance of moss or other terrestrial plants in the Tarim basin. In addition, the relative intensity of 17β(H)-trisnorhopane, 17 β(H),21 α(H)-30-normoretane and 17 β(H)-moretane is lower, but 17α(H)-trisnorhopane and 17 α(H)-30-norhopane is higher in the pyrolysates of the Ordovician kerogens in comparison with the pyrolysates of the Triassic kerogens. Moreover, Pr-1-ene has been detected in pyrolysates of Triassic kerogens. These differences in pyrolysates consist with maturity of kerogens. In conclu- sion, combination of methylation-Py-GC-MS and Py-GC-MS are useful tools to investigate the molecular structure of geomacromolecules and can be subject to type the organic matter, com- pare the maturity of kerogens and carry out the oil-source correlation.

关键词： methylation-Py-GC-MS, kerogens, molecular structure, maturity, source material, Tarim basin.

Seasonal water storage change of the Yangtze River basin.detected by GRACE

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Science China Earth Sciences 2006年第5期49卷 483-491页

作者： HU Xiaogong1, CHEN Jianli1,2, ZHOU Yonghong1, HUANG Cheng1 & LIAO Xinhao1 1. Center for Astro-geodynamics Research, Shanghai Astronomical Observatory, National Astronomical Observatories, Shanghai 200030, China 2. Center for Space Research, University of Texas at Austin, 3925 W. Braker Lane, Suite 200, Austin, TX78750, USA Center for Astro-geodynamics Research Shanghai Astronomical Observatory National Astronomical Observatories Shanghai China Center for Space Research University of Texas at Austin Austin USA

US-Germany co-sponsered satellite gravimetry mission GRACE (Gravity Recovery And Climate Experiment), launched in March 2002, has been producing monthly time series of Earth gravity models up to degree and order of 120. The GRACE mission consists of two identical satellites flying on an almost polar orbit with an altitude of about 300-500 km and satelite-to-satellite ranging of about 220 km. Thanks to the payloads of space-borne GPS receivers, accelerometers and high-precision K-band satelite-to-satellite ranging mesurements, GRACE gravity models are expected to achieve more than one order of magnitude of improvement over previous models at spatial scales of a few hundred kilometers or larger. Recovery of surface mass re-distribution based on GRACE’s time-varying gravity models is applied to studies in solid Earth geophysics, oceanography, climatology and geodesy. At secular time scales, GRACE is expected to provide valuable information on global ice changes, whose variations have profound influences on global climate, and in particular, on sea level changes. At seasonal time scales, GRACE is expected to reveal surface water changes with an ac- curacy of less than 1 cm, or ocean bottom pressure changes with an accuracy of less than 1 mbar (1 mbar =102 Pa). These surface mass redistribution measurements would impove our understanding of the global and regional mass and energy cycles that are critical to human life. Using 15 GRACE monthly gravity models covering the period from April 2002 to December 2003, this study compares seasonal water storage changes recovered from GRACE data and hydrology models at global and regional scales, with particular focus on the Yangtze River basin.of China. Annual amplitude of 3.4 cm of equivalent water height change is found for the Yangtze River basin.with maximum in Spring and Autumn, agreeing with two state-of-the-art hydrology models. The differences between GRACE re- sults and model predictions are less than 1-2 cm. We conclude

关键词： GRACE, earth gravity, water storage, Yangtze River basin.

The control of syndepositional faulting on the Eogene sedimentary basin.fills of the Dongying and Zhanhua sags, Bohai Bay basin

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Science China Earth Sciences 2004年第9期47卷 769-782页

作者： LIN Changsong1, ZHENG Herong2, REN Jianye1, LIU Jingyan1 & Qiu Yigang1 1. Department of Energy Geology, China University of Geosciences, Beijing 100083, China 2. Petroleum Exploration and Production Institute, Sino-Petroleum and Chemistry Cooperation, Beijing 100083, China Department of Energy Geology China University of Geosciences Beijing China Petroleum Exploration and Production Institute Sino-Petroleum and Chemistry Cooperation Beijing China

The Dongying and Zhanhua sags are the major hydrocarbon exploration and produc- tion subbasin. in the Bohai Bay basin. Integrated analysis of the sedimentary basin.fills has shown that the syndepositional faults and their arrangement styles exerted an important influ- ence on the development and distribution of the Eogene depositional systems. The sedimentary filling evolution of the subbasin. reflects the general control of the episodic rifting process. The major long-term active normal faults formed a series of paleogeomorphic accident or slopebreak zones that commonly delineated the subsidiary palaeostructural units and the depositional facies tracts and constrained the general distribution of sedimentary facies zones. The central sag boundary fault slopebreak zones usually determined the distribution of the depocenters of ter- restrial clastic depositional systems, particularly the lowstand fans or deltaic depositional sys- tems, and have proven to be the economically important targets for the exploration of subtle sandstone reservoirs. A variety of syndepositional fault arrangement patterns, including the par- allel, en echelon, combo-like, broom-like fault systems and the fault overlap or transfer zones, have been recognized in the subbasin.. They generated distinctive geomorphic features and exerted a direct influence on sediment dispersal and sandbody distribution during the Eogene synrift stage. It is the key for the prediction of depositional systems tracts and reservoir sand- stones to investigate the activity and distribution of the fault slopebreak zones and reconstruct the structural paleogeomorphy in different basin.filling stages of the basin.evolution.

关键词： episodic rifting, fault slopebreak zone, depositional pattern, Bohai Bay basin.

Miocene Bahean stratigraphy in the Longzhong basin. northern central China and its implications in environmental change

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Science China Earth Sciences 2006年第12期49卷 1270-1279页

作者： LI Jijun1,2, ZHANG Jun1, SONG Chunhui1, ZHAO Zhijun2, ZHANG Yong1, WANG Xiuxi 1, ZHANG Jianming1 & CUI Qiaoyu1 1. Key Laboratory of Western China’s Environmental Systems (Ministry of Education) & College of Earth and Environment Sciences, Lanzhou University, Lanzhou 730000, China 2. Jiangsu Key Laboratory of Environmental Change and Ecological Construction & College of Geography, Nanjing Normal University, Nanjing 210097, China Key Laboratory of Western China’s Environmental Systems (Ministry of Education) & College of Earth and Environment Sciences Lanzhou University Lanzhou China Jiangsu Key Laboratory of Environmental Change and Ecological Construction & College of Geography Nanjing Normal University Nanjing China

Fossil mammal-riched Neogene strata are widely distributed in the southeast corner of the huge Longzhong basin.at Tianshui, Gansu Province, northern central China. Hipparion weihoense, a typical member of late Middle Miocene Bahean stage, was recently excavated at Yaodian along a well-exposed outcrop. Owing to the importance of the Bahean stage in the mammalian evolution and its potential for environmental change, we suggested a name of Yaodian Formation for the stratigra- phy, which is correlated to the Bahe Formation at Lantian, Shaanxi. High resolution paleomagnetic dating of the section shows that the Yaodian Formation covers the period between 11.67 Ma and 7.43 Ma, with the site bearing Hipparion weihoense being estimated at about 10.54―10.30 Ma, providing first magnetostratigraphic chronology for the Bahean Stage. The Yaodian Formation consists of fluvial channel deposits (11.67―10.40 Ma) at the bottom, floodplain deposits in the middle (10.40―9.23 Ma) and shallow lake sediments at the top (9.23―7.43 Ma). This upward fining sequence suggests that the relief in nearby mountain ranges such as West Qinling to the south and Huajia Ling to the north was greatly reduced after long-term denudation, fluvial transport capacity was low, and finally the drainage system was disintegrated, replaced with broad-shallow lakes in which only fine sediments like mud and marlite were deposited, indicating an old stage of development of a planation surface. A remarkable shift in ecology and climatic environment was found at 7.4―7.7 Ma when paleoclimate changed from early warm humid to late dry as indicated by sedimentary facies changed from early shallow lake sequence to late eolian red clays and a former coniferous-deciduous mixed forest was replaced by grassland, leading to great growth of Hipparion Fauna of Baodean stage in the region. Therefore, it is estimated that the present high relief of Qinling and drainage pattern did not come into being until Late Pliocene in response

关键词： Bahean stage,magnetostratigraphy,Yaodian Formation,Neogene,Longzhong basin.

Carbon isotope composition and its implications of Lower Cretaceous Aptian-Albian shallow water carbonates in the Cuoqin basin. North Tibet

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Science China Earth Sciences 2004年第3期47卷 247-254页

作者： ZHU Jingquan1, LI Yongtie2, JIANG Maosheng1 & CHEN Daizhao1 1. Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China 2. Research Institute of Petroleum Exploration and Development, CNPC, Beijing 100083, China Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China Res. Inst. Petroleum Explor./Devt. CNPC Beijing 100083 China

The d 13C values of Lower Cretaceous Aptian-Albian platform-type carbonates in the Cuoqin basin. North Tibet vary between 2.48 and 5.46. The mean value is 3.93. The values are not only provided with positive excursion, but also 1.17 higher than those of con-temporaneous pelagic carbonates which possess pretty high d 13C values. The origin is ap-proached. During the oceanic anoxic events, a great number of organisms were rapidly buried, causing the increase of the d 13C value of oceanic total dissolved carbon (TDC) and generally promoting the values of marine carbonates. After that, owing to the organisms undergoing dif-ferent isotopic fractionation in the paleo-ocean with stratified structure, d 13C values of shallow sea carbonate were obviously higher than those of pelagic carbonates.

关键词： shallow water carbonate, stable carbon isotope, paleooceanography, Aptian-Albian stage, Cuoqin basin.

Study on consumption efficiency of soil water resources in the Yellow River basin.based on regional ET structure

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Science China Earth Sciences 2008年第3期51卷 456-468页

作者： WANG Hao YANG GuiYu JIA YangWen QIN DaYong Department of Water Resources Institute of Water Resources and Hydropower ResearchBeijing 100044China

Based on the regional water resources character, the concept of soil water resources is first redefined, and then associated with their transfer relationship in the hydrological cycle, Evapotranspiration (ET)-based consumption structure and consumption efficiency of soil water resources are analyzed. According to ET 's function in productivity, the consumption efficiency of soil water resources is di- vided into three classes: high efficient consumption from vegetation transpiration, low efficient con- sumption from soil evaporation among plants with high vegetation coverage and inefficient consump- tion from soil evaporation among plants with low vegetation coverage and bare soil evaporation. The high efficient and low efficient consumption were further classified as productive consumption. The ineffi- cient consumption is considered non-productive consumption because it is significant in the whole hydrological cycle process. Finally, according to these categories, and employing a WEP-L dis- tributed hydrological model, this paper analyzes the consumption efficiency of soil water resources in the Yel- low River basin. The results show that there are 2078.89×108 m3 soil water resources in the whole basin. From the viewpoint of consumption structure, the soil water resources are comprised of 381.89×108 m3 transpiration consumption from vegetation and 1697.09×108 m3 evaporation consumption from soil among plants and bare soil. From the viewpoint of consumption efficiency, soil water re- sources are composed of 920.11×108 m3 efficient consumption and 1158.86×108 m3 of inefficient con- sumption. High efficient consumption accounts for 41.5 percent of the total efficient consumption of the whole basin. low efficient for 58.5 percent. Furthermore, consumption efficiency varies by region. Compared with ET from different land use conditions, the whole basin.appears to follow the trend of having the greatest proportion of consumption as inefficient consumption, followed by l

关键词： soil water resources evapotranspiration (ET) consumption efficiency Yellow River basin.