bluuebunny/crossref_metadata_2025 huggingface dataset:
Extension of the Louzidian Metamorphic Core Complex and Development of Supradetachment Basins in Southern Chifeng, Inner Mongolia, China
Authors: Xinshe WANG , Yadong ZHENG , Wen JIA
Published: September 2010

Abstract The Louzidian metamorphic core complex (LMCC) in southern Chifeng is located on the northern margin of the North China craton. Structural analyses of the LMCC and its extensional detachment system indicate that the LMCC experienced two‐stage extension. The ductile regime experienced top‐to‐northeast shearing extension and the brittle detachment fault underwent top‐down‐outwards slipping. Between these two stages, a semi‐ductile regime recorded the transition from ductile to brittle. The hanging wall of the detachment fault is similar to those classic supradetachment basins in western North America. Analyses of provenance and paleocurrent directions in the basins show that there were two filling stages. In the early stage, materials came from the southwest margin of the basin and the hanging wall of the detachment system and were transported from southwest to northeast; while in the late stage, deposits were derived from the footwall of the detachment fault and transported outwards to the two sides of the core complex. Since the filling period of the basins is from the late Jurassic to the late Cretaceous and it is coeval with the extension, the two filling stages reflect the two‐stage history of the detachment fault. The large‐scale late Jurassic underplating in the deep crust of the Chifeng area led to thickening and heating of the middle‐upper crust and trigged the extension at depths and volcanism on the surface. In the early Cretaceous the upper plate of the detachment fault moved northeastwards and sediments were transported from southwest to northeast, while in the late Cretaceous the core complex was uplifted rapidly, the original basin was separated by the uplifted core, and lower‐plate‐derived debris was deposited in the adjacent upper‐plate basins of the detachment fault. Evidentially, the development of the supradetachment basins were controlled by the extension and in turn the fillings in the basins recorded information of the extension, which has provided new evidence for kinematic interpretation of the Louzidian core complex.
Formation Mechanism of “Drag Depressions” and Irregular Boundaries in Intraplate Deformation
Authors: Jun DENG , Dinghua HUANG , Qingfei WANG , Zengqian HOU , Qingtian LÜ , Lingqing YAO , Hongbo XIN , Qiang ZHANG , Yanguang WEI
Published: September 2010

Abstract Almost all intraplate caprocks experienced strong deformation during the convergence of microplates, and then disintegrated into many secondary geologic units with the special characters, such as irregular boundaries and particular structural assemblages. In order to understand the formation mechanism of these special phenomena, a rheological experiment on the structural scenery of the Tongling area is carried out. The result shows that the primary regular and uniform boundaries of the Tongling area becomes irregular because of the enclosing and confinement of surrounding geological units in the process of “compression‐shearing‐rotation‐drag”; simultaneously, two specific “drag depressions” developed at two opposite corners of the block. The former and the later phenomena can be regarded as a typical regional‐scale rheological effect and necessary outcome of intraplate deformation respectively.
Dynamic Features of Angular Unconformity Formation—Extensional and Compressional Angular Unconformities
Authors: Zhongquan LI , Shihai XU , Danlin YING , Jianhui Han
Published: September 2010

Abstract Angular unconformity is one of the most direct and strongest evidences for approving the tectonic movements of the earth's crust. Its dynamic genesis process has been understood to be mainly related to the compressional setting for a long time. Especially, in a detailed structural analysis for a specific region, when an angular unconformity is discovered people would regard it as the result of orogenic movements of a certain period or a certain episode and neglect the extensional facts. Based on a dialectical point of view of extension‐compression, this paper has proved that angular unconformities can be formed not only in compressional settings, but also in extensional ones. Further more, their geological features are compared and he possible genetic mechanisms for angular unconformity under different dynamic settings are studied.
Magmatic Event at the End of the Archean in Eastern Hebei Province and Its Geological Implication
Authors: Yuansheng GENG , Fulai LIU , Chonghui YANG
Published: September 2010

Abstract: By using the SHRIMP U‐Pb and single zircon stepwise evaporation methods, the authors have obtained some results for granitoids from eastern Hebei Province. The Yuhuzhai hyperthene tonalitic granite was formed 2550 Ma ago, the Qingyangshu gabbroic gneiss 2536 Ma, the Yinmahe granodioritic gneiss near Lücao, Lulong County, 2533 Ma, the gabbro‐dioritic gneiss near Longwan, Qianxi County, 2518‐2515 Ma, the Qiuhuayu trondjemitic gneiss at Zunhua 2515 Ma, the Xiaoguanzhuang tonalitic gneiss at Zunhua 2495 Ma, and the Cuizhangzi gneiss in Qianxi County 2492 Ma. These geochronilogical data demonstrate that, though diverse in composition, type and origin, the granitic gneisses in eastern Hebei Province were emplaced and crystallized in a rather short period of magmatic activity. The formation of such a great amount of gneisses in this small time gap suggests that it was a critical crust accretion stage at the end of Neoarchean. The fact that granitoids of various types occurred at the same time implies a large‐scale underplating (mantle plume) activity, which was then responsible for the crust accretion.
Paleoproterozoic Potassic Granitoids in the Sushui Complex from the Zhongtiao Mountains, Northern China: Geochronology, Geochemistry and Petrogenesis
Authors: Wei TIAN , Shuwen LIU , Huafeng ZHANG
Published: September 2010

Abstract: Paleoproterozoic potassic granitoids in the southern Sushui Complex from the Zhongtiao Mountains yielded SHRIMP zircon U‐Pb ages of 1968‐1944 Ma. Lithologically, the potassic granitoid series consists chiefly of monzodiorite, quartz monzonite and syenogranite. Their trace elements and Sm‐Nd isotope characteristics indicate that they were derived from partial melting of Archean TTG rocks in an overthickened continental crust. Petrogenesis of this potassic granitoid series implies a collisional environment within the Trans‐North China Orogen in the Paleoproterozoic, which supports a tectonic model of Eastern and Western Continental Blocks being amalgamated in the Paleoproterozoic.
U‐Pb Zircon Dating of the Granitic Conglomerates of the Hutuo Group: Affinities to the Wutai Granitoids and Significance to the Tectonic Evolution of the Trans‐North China Orogen
Authors: ZHANG Jian , ZHAO Guochun , Sanzhong LI , SUN Min , Shuwen LIU , XIA Xiaoping , HE Yanhong
Published: September 2010

Abstract: The Wutai Complex associated with the adjacent Fuping and Hengshan Complexes represents the best and classical cross‐section in the middle segment of the Trans‐North China Orogen, generally divided into Eastern and Western Blocks. Unconformably overlying the Wutai and Fuping Complexes is the Hutuo Group considered as the youngest lithostratigraphic unit in the region and important both for interpreting Precambrian history as well as the overall evolution of the Trans‐North China Orogen. Lack of knowledge about provenance of the sedimentary rocks in this group has hindered understanding of the depositional environments and tectonic significance. LA‐ICP‐MS was applied to obtain U‐Pb zircon ages for the granitic pebbles, the lowest lithostratigraphic rock of the Hutuo Group, which, combined with previous lithostratigraphic, geochronological, structural and metamorphic data, provides new constraints on the sedimentary provenance and tectonic evolution of the region. The sequence of the Hutuo Group ranges upward from lower basal conglomerates and volcaniclastic rocks (Doucun Subgroup), through clastic sediments, slates, dolomites and marbles (Dongye Subgroup), to sandstones and conglomerates at the top (Guojiazhai Subgroup). Zircons from granitic pebbles preserved in the Doucun Subgroup basal conglomerates give weighted mean 207Pb/206Pb ages between 2517 Ma and 2566 Ma, which are the same as those for the late Archean Wutai Granitoids, indicating that the pebbles were derived from the Wutai granitic intrusions (2566‐2515 Ma). Based on the new data and previous studies, combined with an igneous zircon crystallization age of 2087±9 Ma obtained for volcanics in the Hutuo Group, the Hutuo Group was deposited in a subduction‐related retro‐arc foreland basin environment that developed behind the Wutai arc during the eastward‐directed subduction of the Western Block beneath the western margin of the Eastern Block. This basin underwent long‐lived sedimentation and finally closed during the ∼1850 Ma collisional event that resulted in the final amalgamation of the North China Craton.
Tectonic Constraints on the Transformation of Paleozoic Framework of Uplift and Depression in the Ordos Area
Authors: Qingfei WANG , Jun DENG , Dinghua HUANG , Liqiang YANG , Bangfei GAO , Hao XU , Shaoqing JIANG
Published: September 2010

Abstract: During the Paleozoic, the Ordos area in the western North China Plate was located at the intersecting position of microplates and controlled by their interaction. The structural framework in the Ordos area, which underwent transformations in the Ordovician, the Carboniferous and the Permian respectively, was dominated by the alternation of uplift and depression. The transformations of structural framework are utilized as the clues to investigate the microplates' interacting type and its response in the Ordos area. According to the regional structural evolution, the Ordos area is simplified into an isopachous, isotropic and elastic shell model, and under proposed various boundary conditions, three series of numerical simulations corresponding to the three structural transformations are carried out to determine the detailed tectonic constraints. Numerical simulations reveal that the structure of the uplift and depression, which is similar to the actual pattern, develops only under one special boundary condition in each of the three series, indicating that the structural framework responds to the unique tectonic background. The simulation results show that in the Early Paleozoic, the L‐shaped paleouplift formed nearby the southwestern corner of the Ordos area because the intensity of the compressions in the southern and western boundaries resulting from the ocean‐continent collisions was similar. In the Late Paleozoic, it evolved into continent‐continent (or arc‐continent) interaction in the southern and northern boundaries; in the preliminary stage of the interaction, since the interface between the North China Plate and the plates on the south and north was narrow, the relative acting force was little and the regional western boundary immobile, and the structural framework in the basin was characterized by the N‐S trending slender‐waist—shaped uplift; as the interface between the plates expanded gradually, the extrusive force in the southern and northern boundaries of the North China Plate increased, resulting in the paleogeographic divisions showing E‐W trending, and, the western boundary of the basin was extruded westward due to the intense compression inducing the local NE trending of paleogeographic division in the central area. The simulation results further reflect that the symmetry of the uplift‐depression pattern is restricted by that of the boundary conditions, suggesting that the Paleozoic structural transformations of the Ordos area under boundary constraints accord with the universal physical symmetrical principle.
Spatial and Temporal Distribution of the Cryptospirifer Fauna (Middle Permian Brachiopods) in the Tethyan Realm and Its Paleogeographic Implications
Authors: Xiaochi JIN , Lipei ZHAN
Published: September 2010

Abstract: The middle Permian Cryptospirifer fauna (brachiopod) has hitherto been found in more than 30 localities in the Yangtze Platform, South China. Examination of data from various localities shows that it occurs stratigraphically in three intervals in the range from the upper Kungurian to Wordian. In the Baoshan block in western Yunnan the fauna occurs in the basal part of the Daaozi Formation and is of possibly an early Wordian age. Outside China the Cryptospirifer fauna has been reported from central and northwest Iran and central Turkey, where the fauna may have an age around the Wordian\Capitanian boundary. Rapid global warming since the late Early Permian and possession of other suitable environmental factors such as proper substrate, clastic input and water depth enabled the Gondwana‐derived Baoshan Block and related tectono‐stratigraphic units in Iran and Turkey to host the Cryptospirifer fauna, a fauna evolved in the Yangtze Platform that is a type area of the Cathaysian province.
A New Mamenchisaurid Dinosaur from the Middle Jurassic of Yuanmou, Yunnan Province, China
Authors: Junchang Lü , Tianguang LI , Shimin ZHONG , Qiang JI , Shaoxue LI
Published: September 2010

Abstract: A new mamenchisaurid dinosaur, Eomamenchisaurus yuanmouensis gen et sp. nov. is erected based on an incomplete skeleton from the Zhanghe Formation, the Middle Jurassic of Yuanmou, Yunnan Province. The new taxon is characterized by absence of pleurocoels in dorsal vertebrae and the dorsal verterbrae with slightly convex anterior articular surfaces, moderately concave posterior articular surfaces; the fourth trochanter is developed posteromedially on the femur; length ratio of the tibia to the femur is approximately 0.64; and the shaft of the ischium is rod‐like. Two fused centra of the posterior dorsal vertebrae (the presumed 9th and the 10th dorsal vertebrae) are similar to those in other mamenchisaurid dinosaurs, including Mamenchisaurus hochuanesis, M. youngi and Chuanjiesaurus anaensis. Therefore, fusion of centra of the ninth and the tenth dorsal vertebrae can be recognized as a synapomorphic character of the Mamenchisauridae.
SHRIMP Zircon U‐Pb and Molybdenite Re‐Os Datings of the Superlarge Donggou Porphyry Molybdenum Deposit in the East Qinling, China, and Its Geological Implications
Authors: Huishou YE , Jingwen MAO , Yongfeng LI , Baojian GUO , Changqing ZHANG , Jun LIU , Quanren YAN , Guoyin LIU
Published: September 2010

Abstract: Located in the eastern part of the East Qinling molybdenum belt, the Donggou deposit is a superlarge porphyry molybdenum deposit discovered in recent years. The authors performed highly precise dating of the mineralized porphyry and ores in the Donggou molybdenum deposit. A SHRIMP U‐Pb zircon dating of the Donggou aluminous A‐type granite‐porphyry gave a rock‐forming age of 112±1 Ma, and the ICP‐MS Re‐Os analyses of molybdenite from the molybdenum deposit yielded Re‐Os model ages ranging from 116.5±1.7 to 115.5±1.7 Ma for the deposit. The ages obtained by the two methods are quite close, suggesting that the rocks and ores formed approximately at the same time. The Donggou molybdenum deposit formed at least 20 Ma later than the Jinduicheng, Nannihu, Shangfanggou and Leimengou porphyry molybdenum deposits in the same molybdenum belt, implying that these deposits were formed in different tectonic settings.
Three New Stoneflies (Insecta: Plecoptera) from the Yixian Formation of Liaoning, China
Authors: Yushuang LIU , Dong REN , SINITSHENKOVA Nina D. , Chungkun SHIH
Published: September 2010

Abstract: Three new genera and species Archaeoperla rarissimus gen. et sp. nov. (Perlidae), Liaotaenionema tenuitibia gen. et sp. nov. (Taeniopterygidae) and Parvinemoura parvus gen. et sp. nov. (?Nemouridae) are described and illustrated. All of them were collected from Yixian Formation of the western Liaoning, China. Hitherto, A. rarissimus is the oldest species possessing typical characters of Perlidae; the finding of L. tenuitibia indicates taeniopterygids once lived in the northeastern China in the late Mesozoic, but frequent volcanic activities, climate changes, or other environmental changes might have resulted in the disappearance of Taeniopterygidae in northern China after Mesozoic. Ancestral groups of Nemouridae have been abundant from Middle Jurassic, and male genitalia of P. parvus gen. et sp. nov. has been developed and similar to extant Nemouridae in the late Mesozoic. The stonefly fossils found from Yixian Formation are not divers at the species level, but rich at the family level. The diversity of stonefly implies different microclimate existed in the northeastern China at that time. A large old lacustrine basin existed in the western Liaoning, surrounded by hygrophilous plants on swampland and lake shore, warm and humid; tall arbor and boscage on the hillside nearby, mild and dry; mountains in the distance, rivulets running among the mountains, cool and wet. Many insects, prefer cool climate (e.g. stonefly, raphidiopterans, et al.), lived in the mountains with rivulets.
Jurassic Tectonic Revolution in China and New Interpretation of the “Yanshan Movement”
Authors: Shuwen DONG , Yueqiao ZHANG , Changxing LONG , Zhenyu YANG , Qiang JI , Tao WANG , Jianming HU , Xuanhua CHEN
Published: September 2010

Abstract: With acquisition and accumulation of new data of structural geological investigations and high‐resolution isotopic dating data, we have greatly improved our understanding of the tectonic events occurring in eastern China during the period from the Late Jurassic to Early Cretaceous and may give a new interpretation of the nature, timing and geodynamic settings of the “Yanshan Movement”. During the Mid‐Late Jurassic (165±5 Ma), great readjustment of plate amalgamation kinematics took place in East Asia and the tectonic regime underwent great transformation, thus initiating a new tectonic regime in which the North China Block was the center and different plates converged toward it from the north, east and southwest and forming the “East Asia convergent” tectonic system characterized by intracontinental subduction and orogeny. As a consequence, the crustal lithosphere of the East Asian continent thickened considerably during the Late Jurassic, followed immediately by Early Cretaceous substantial lithospheric thinning and craton destruction featured by drastic lithospheric extension and widespread volcano‐magmatic activities, resulting in a major biotic turnover from the Yanliao biota to Jehol Biota. Such a tremendous tectonic event that took place in the continent of China and East Asia is the basic connotation of the “Yanshan Movement”. In the paper, according to the deformation patterns, geodynamic settings and deep processes, the “Yanshan Movement” is redefined as the Late Jurassic East Asian multi‐directional plate convergent tectonic regime and its associated extensive intracontinental orogeny and great tectonic change that started at ˜165±5 Ma. The substantial lithospheric attenuation in East China is considered the post‐effect of the Yanshanian intracontinental orogeny and deformation.
Source Rocks for the Giant Puguang Gas Field Sichuan Basin: Implication for Petroleum Exploration in Marine Sequences in South China
Authors: Huayao ZOU , Fang HAO , Yangming ZHU , Tonglou GUO , Xunyu CAI , Pingping LI , Xuefeng ZHANG
Published: September 2010

Abstract: Detailed geochemistry studies were conducted to investigate the origin of solid bitumens and hydrocarbon gases in the giant Puguang gas field. Two types of solid bitumens were recognized: low sulfur content, low reflectance (LSLR) solid bitumens in sandstone reservoirs in the Xujiahe Formation and high sulfur content, high reflectance (HSHR) solid bitumens in the carbonate reservoirs in the Lower Triassic Feixianguan and Upper Permian Changxing formations. Solid bitumens in the Upper Triassic Xujiahe Formation correlate well with extracts from the Upper Triassic to Jurassic nonmarine source rocks in isotopic composition of the saturated and aromatic fractions and biomarker distribution. Solid bitumens in the Feixianguan and Changxing formations are distinctly different from extracts from the Cambrian and Silurian rocks but display reasonable correlation with extracts from the Upper Permian source rocks both in isotopic composition of the saturated and aromatic fractions and in biomarker distribution, suggesting that the Permian especially the Upper Permian Longtan Formation was the main source of solid bitumens in the carbonate reservoirs in the Feixianguan and Changxing formations in the Puguang gas field. Chemical and isotopic composition of natural gases indicates that the majority of hydrocarbon gases originated from sapropelic organic matter and was the products of thermal cracking of accumulated oils. This study indicates that source rock dominated by sapropelic organic matter existed in the Upper Permian and had made major contribution to the giant Puguang gas field, which has important implication for petroleum exploration in marine sequences in South China.
Kinetic Modeling the Formation of Low‐mature Gases and Analysis of the Possibility to Be Accumulated
Authors: Yanhua SHUAI , Hui WANG , Shuichang ZHANG , Aiguo SU
Published: September 2010

Abstract: At present, shallow gases have received much attention due to low cost in exploration and production. Low‐mature gases, as one significant origin to shallow gas, turns to be an important research topic. The present understanding of low‐mature gases is confined within some geological cases, and few laboratory studies have been reported. Therefore, the potential and characters of low‐mature gases are not clear up to now. Here, two premature samples (one coal and the other shale) were pyrolyzed in a gold confined system. The gaseous components including hydrocarbon gases and non‐hydrocarbon gases were analyzed. Based on kinetic modeling, the formation of low‐mature gases was modeled. The results showed that during low mature stage, about 178 mL/gTOC gas was generated from the shale and 100 mL/gTOC from the coal. Two third to three fourth of the generated gases are non‐hydrocarbon gases such as H2S and CO2. The total yields of C1–5 for the two samples are almost the same, 30–40 mL/gTOC, but individual gaseous hydrocarbon is different. The shale has much lower C1 but higher C2–5, whereas the coal has higher C1 but lower C2–5. Hydrocarbon gases formed during low‐mature stage are very wet. The stable carbon isotope ratios of methane range from −40% to −50% (PDB), in good consistence with empiric criterion for low‐mature gases summed up by the previous researchers. The generation characters suggest that the low‐mature gases could be accumulated to form an economic gas reservoir, but most of them occur only as associated gases.
The Occurrence of Oleananes in the Beibuwan Basin and Its Application to the Study of Maturity and Oil‐Source Rock Correlation
Authors: Meijun LI , Tieguan WANG , Ju LIU , Meizhu ZHANG , Hong LU , Qinglin MA , Lihui GAO
Published: September 2010

Abstract: The oleanane parameter, i.e., OP (oleananes/(oleananes+C30hopanes)) in the two sedimentary columns of the Beibuwan Basin, South China Sea, can be used to delimit the top of oil generation window, with Ro (/%) of 0.53 in Well M1 and 0.55 in Wells H1/Hd1/Hd2, respectively. Comparing with vitrinite reflectance (Ro/%), the OP features a dynamic range and can indicate the oil generation window more precisely. By using OP and other geochemical indices, the oil‐source correlation is also conducted. It suggests that the oils in wells M1 and M2 are derived from the source rocks in situ. The mudstone in Huachang uplift is not the main source rocks for oils in this area. The OP is also a useful oil‐source correlation parameter in some Tertiary lacustrine basins.
Metallogenic Epoch and Ore‐forming Environment of the Lamasu Skarn‐porphyritic Cu‐Zn deposit, western Tianshan, Xinjiang, NW China
Authors: Zuoheng ZHANG , Zhiliang WANG , Longsheng WANG , Guochao ZUO
Published: September 2010

Granitic rocks, widely developed in the Lamasu copper ore region, western Tianshan were formed at 390.5±7.7 Ma according to the SHRIMP zircon U‐Pb dating of the plagioclase granite porphyry. Based on the regional tectonic evolution and published chronological data of both diagenesis and mineralization, the Biezhentao‐ Kokirqin region was rolled into the orogen associated with the closure of Yili Ocean during early Devonian. The N‐S‐trending thrust faults were formed during this period and accompanied by the intrusion of granitic rocks. On this stage, the paleo‐Asian Ocean Plate entered into the early collision orogenic phase and the plagioclase granite porphyry intruded (390.5±7.7 Ma) and replaced with limestone of the Mesoproterozoic Kusongmuqieke Group, Jixianian System and formed the early phase of skarn‐type copper mineralization in the Lamasu region. Furthermore, the subduction‐melting of Bayingou Ocean Plate during Carboniferous generated a deep‐seated magmatic chamber in the Lamasu copper ore region which located in the northwestern part of the Paleozoic Biezhentao‐Kokirqin island arc. The magmatic chamber segregated Cu‐bearing magmas, which transported upward to the shallow earth crust along the faults or fractures and formed the Cu‐hosting porphyry. According to the research on the characteristics of the ore deposit and the ore‐forming environment as mentioned above, the Lamasu Cu‐Zn deposit was characterized by the superposing of mineralization at different geological settings and it was skarn‐porphyritic type.
Exhalative Lead‐Zinc Deposits in Shallow Sea, Southern Xicheng Belt, Gansu Province
Authors: Xinyou ZHU , Dongbo WANG , Zhiguo WEI , Xiaoping QIU , Ruiting WANG
Published: September 2010

SEDEX‐type lead‐zinc deposits in the southern belt of the Xicheng Devonian basin, Gansu Province has been already identified. However, the sedimentary environment of the limestone and philite of the Xihanshui Group within which the lead‐zinc deposits occur is littoral and shallow sea. This is different from those in the northern belt such as the Changba‐Lijiagou lead‐zinc deposits, which were formed in deep sea. The reef and bioclastic limestone are widespread in the southern belt. Particularly they are associated with lead‐zinc ores and there are no striae and banding but massive or disseminated structures. It is discovered that the black chimney consists of sphalerite, ankerite, pyrite and galena, in which black, coarse and radial sphalerite occurs as irregularly veins or cylindricality with a width of 10–40 cm in the center, and it is surround by fine ankerite and minor celestite with ribbon structure. The immediate wall rock of the chimney, reef limestone, was unaltered and the outside reef and bioclastic limestone were intensively silicified. Those silicified reef and bioclastic limestone host disseminated lead‐zinc ores of the Luoba and Bijiashan type. It is concluded that the exhalative system occurred in a shallow sea in the Givetian of the middle Devonian. Brine is boiled due to low pressure, and a great deal of lead and zinc was dispersed in the interface between the limestone and phyllite and formed a source bed. In the Triassic period, meta‐hydrothermal fluids leached and extracted metals from the source bed, and then moved and mineralized in open space such as arches and inverse limbs of anticlines, and formed massive and vein ores such as the Jianyagou and Dengjiashan type deposits.
Experimental Study of the Distribution of Au and Cu in Aqueous Vapor Phase at High Temperatures and Its Role on Ore‐forming Transportation
Authors: Ronghua ZHANG , Shumin HU , Xuetong ZHANG
Published: September 2010

This study focuses on experiments of Au and Cu dissolved in vapor phase in hydrothermal fluids. Experiments prove that Au and Cu can re‐distribute in vapor phase and liquid phase during separation of Au‐ and Cu‐bearing supercritical fluids to vapor and liquid phases. These experimental results can illustrate some ore geneses, where boiling phenomena of ore fluids were found. Au‐ and Cu‐ bearing NaHCO3‐HCl solutions were heated up to more than 350°C in the main vessel, and then passed through a phase separator in a temperature range from 250°C to 300°C, separated into vapor and liquid phases. We collected and analyzed the liquid and vapor samples separately, and found that Au and Cu dissolved and distributed in vapor phase. In some cases, the concentrations of Au and Cu in vapor are higher than those in liquid phase. Those experiments are used to interpret field observations of fluid inclusion data of some Au and Cu deposits, and demonstrate that some Au and Cu ore deposits are derived from metals transportation in vapor phase.
Permafrost Characteristics of the Qinghai‐Tibet Plateau and Methods of Roadbed Construction of Railway
Authors: Fujun NIU , Jian XU , Zhanju LIN , Qingbai WU , Guodong CHENG
Published: September 2010

Permafrost along the Qinghai‐Tibet railway is featured by abundant ground ice and high ground temperature. Under the influence of climate warming and engineering activities, the permafrost is under degradation process. The main difficulty in railway roadbed construction is how to prevent thawing settlement caused by degradation of permafrost Therefore the proactively cooling methods based on controlling solar radiation, heat conductivity and heat convection were adopted instead of the traditional passive methods, which is simply increasing thermal resistance. The cooling methods used in the Qinghai‐Tibet railway construction include sunshine‐shielding roadbeds, crushed rock based roadbeds, roadbeds with rock revetments, duct‐ventilated roadbeds, thermosyphon installed roadbeds and land bridges. The field monitored data show that the cooling methods are effective in protecting the underlying permafrost, the permafrost table was uplifted under the embankments and therefore the roadbed stability was guaranteed.
Distribution of Palygorskite in the Lingtai Profile of Chinese Loess Plateau: Its Paleoclimatic Implications
Authors: Qiaoqin XIE , Tianhu CHEN , Jun CHEN , Junfeng JI , Huifang XU , Xiaochun XU
Published: September 2010

Palygorskite is a typical indicator mineral of the arid and strong evaporation environment. Distribution of palygorskite in loess‐red clay sequences may act as an important indicator for reconstruction of the paleoenvironment and paleoclimate. In this paper, field emission scanning electron microscope and high‐resolution transmission electron microscope observations on the red clay‐loess‐paleosol of the Renjiapo profile at Lingtai, Gansu Province indicate that palygorskite occurs widely in red clay sequences formed before 3.6 Ma, but no occurrence has been found in eolian sediments since 3.2 Ma. Micromorphological features and microstructure of palygorskite show that it is an autogenic mineral formed during pedogenesis, and transformed from illite‐montmorillonite under the pore water action. In the Lingtai profile, the disappearance horizon of palygorskite is consistent with those of increasing magnetic susceptibility, dust flux and depositional rate. The distribution of palygorskite in the profile indicates that the interval of around 3.6 Ma was an important transformation period of the East Asian paleomonsoon, when changes took place in the East Asia paleoclimate pattern, i.e. a high‐frequency strong fluctuation alternative evolution of the environment. Therefore, palygorskite is a key indicator mineral of the East Asian paleomonsoon evolution of that time.
Removal of Arsenic(V) from Aqueous Solutions by Lanthanum‐loaded Zeolite
Authors: Hongping PU , Jiangbo HUANG , Zhe JIANG
Published: September 2010

A new adsorption process for the removal of As(V) ion from aqueous solutions is studied in this paper using lanthanum‐loaded zeolite. The removal efficiency of different adsorbents, activated alumina and activated carbon are obtained in the study for comparison. The results show that lanthanum‐loaded zeolite is an effective adsorbent for the removal of As(V) from aqueous solutions. Then, the pH effect and regeneration of modified zeolite on the As(V) removing efficiency are also assessed. It functions with a wide range of pH (2–8). After adsorption, zeolite adsorbed with As(V) ions can be regenerated successfully with 1M NaOH. Based on the data obtained, an adsorption mechanism and the possible complex structure are tentatively presented. Compare to other adsorbents, easy availability of this adsorbent, excellent adsorption capacity, wide optimum pH range, and regeneration are expected to be utilized in practical operations.
Three Practical Methods for Analyzing Slope Stability
Authors: Shiguang XU , Shitao ZHANG , Chuanbing ZHU , Ying YIN
Published: September 2010

Since the environmental capacity and the arable as well as the inhabitant lands have actually reached a full balance, the slopes are becoming the more and more important options for various engineering constructions. Because of the geological complexity of the slope, the design and the decision‐making of a slope‐based engineering is still not practical to rely solely on the theoretical analysis and numerical calculation, but mainly on the experience of the experts. Therefore, it has important practical significance to turn some successful experience into mathematic equations. Based upon the abundant typical slope engineering construction cases in Yunnan, Southwestern China, 3 methods for analyzing the slope stability have been developed in this paper. First of all, the corresponded analogous mathematic equation for analyzing slope stability has been established through case studies. Then, artificial neural network and multivariate regression analysis have also been set up when 7 main influencing factors are adopted.
The Diagenesis of Plant Lipids during the Formation of the Krepoljin Coal Basin (Serbia) — Using Multivariate Statistical Analysis in the Saturated Biomarkers
Authors: DEVIĆ Gordana , JOVANĈIĆEVIĆ Branimir
Published: September 2010

Abstract: The composition of the saturated hydrocarbon fraction of soluble organic matter (bitumen) from the Krepoljin brown coal basin (East Serbia) of Miocene age was investigated. The Krepoljin basin is especially interesting from a geochemical point of view. Namely, by the end of Tertiary Period, the basin was covered by powerful Mesozoic formations of great possibilities, the bedding became hermetically enclosed and protected from subsequent external influences. The nature of early diagenetic processes in the environment with abundant accumulation of organic substance is defined by the molecular content of bitumen through the connections of molecular structures to potential precursors in paleoplant phylla, as well as by the degree of their diagenetic transformations. The hierarchy of parameters based on molecules of saturated hydrocarbons was determined by applying the principal component analysis to the soluble organic matter. The most significant, most “loadings” values of component C1, are the plant types such as precursors or participants in early diagenetic transformations of steranes Cs27‐algal precursor material, Cs28‐moulds, Cs29‐higher land and water plants; resinous from the group of higher plant gymnosperms (G); also triterpanes a and β‐amirin‐dicotyledonous angiosperms (A) and bacterial and/or terrestrial plants population represented by hopanes/moretanes; as well as the parameters which describe the degree of diagenetic/maturation transformation of precursor biomass, and based on next reactions: (1) shifting of methyl group, influenced by the inorganic sediment constitutents, sterane‐rearranged steranes, (2) isomerization in the ring system, αααr̊βββ C29 sterane as well as (3) isomerization on chiral center of the side chain sequence Rr̊S C29 sterane S/(S+R). Additionally, a pyrite‐derived inhibitory effect on the rearrangment of C29 steranes must be taken into account, but not on triterpanes reaction. Nonappearance of statistically important correlations, before all with maturational depended parameters, and after all also with source indicators contributies to the affirmation of the newly‐suggested parameter α‐Phyllocladane/S27 as the real source biomarker of coal. Indicators derived from the distribution and abundance of n‐alkanes and isoprenoid alkanes are of less significance in hierarchy of parameters.
Early Cretaceous Tectonism and Diatoms in Korea
Authors: CHANG Ki‐Hong , PARK Sun‐Ok
Published: September 2010

Abstract: The Early Cretaceous Sindong Group, a non‐marine molasse, unconformably overlies the folded earliest Cretaceous Myogok Formation. The tectonism that folded the Jaseong Synthem including the Myogok and other formations is here called the Nakdong‐Jaeryeonggang (N‐J) tectonism. The Oknyeobong and Dabokni Formations are discussed to show that they belong to the Jaseong Synthem. The Dabokni Formation yielded fossil diatoms whose age has been referred as the “earliest Cretaceous” based on the geologically constrained age of the fossil‐bearing deposit. The age of the N‐J tectonism appears Barremian as it is between the Hauterivian Myogok Formation and the Aptian Sindong Group with the TPN (Trigonioides‐Plicatounio‐Nippononaia) fauna. The N‐J tectonism, an orogeny, quite deformed pre‐Aptian strata in Korea, but can hardly find its reported equivalent in NE China. A revised correlation table shows that the Jaseong‐Sindong sequence corresponds to the Jehol Group of China. The Sindong‐Hayang transition was characterized by basin migration and dextral rotation probably caused by the Tan‐Lu fault system in a broad sense.
Soft‐sediment Deformation Structures Related to Earthquake from the Devonian of the Eastern North Qilian Mts. and Its Tectonic Significance
Authors: Yuansheng DU , Yajun XU , Jianghai YANG
Published: September 2010

Abstract: Devonian in the North Qilian orogenic belt and Hexi Corridor developed terrestrial molasse of later stage of foreland basin caused by collision between the North China plate and Qaidam microplate. The foreland basin triggered a intense earthquake, and formed seismites and earthquake‐related soft‐sediment deformation. The soft‐sediment deformation structures of Devonian in the eastern North Qilian Mts. consist of seismo‐cracks, sandstone dykes, syn‐depositional faults, microfolds (micro‐corrugated lamination), fluidized veins, load casts, flame structures, pillow structures and brecciation. The seismo‐cracks, syn‐depositional faults and microfolds are cracks, faults and folds formed directly by oscillation of earthquake. The seismic dykes formed by sediment instilling into seismic cracks. Fluidized veins were made by instilling into the seismo‐fissures of the fluidized sands. The load casts, flame structures and pillow structures were formed by sinking and instilling caused from oscillation of earthquake along the face between sandy and muddy beds. The brecciation resulted from the oscillation of earthquake and cracking of sedimentary layers. The seismites and soft‐sediment deformations in Devonian triggered the earthquake related to tectonic activities during the orogeny and uplift of North Qilian Mts.
Cretaceous Volcanic Events in Southeastern Jilin Province, China: Evidence from Single Zircon U‐Pb Ages
Authors: Yuejun CHEN , Chunlin SUN , Yuewu SUN , Wei SUN
Published: September 2010

Abstract: Mesozoic volcanic rocks in southeastern Jilin Province are an important component of the huge Mesozoic volcanic belt in the northeastern area. Study of the age of their formation is of great significance to recognize Mesozoic volcanic rule in northeastern China. Along with the research of rare Mesozoic biota and extensive Mesozoic mineralization in western Liaoning, a number of researchers have focused on Mesozoic volcanic events. The authors studied the ages of the Cretaceous volcanic rocks in southeastern Jilin Province using single Zircon U‐Pb. The result shows that the Sankeyushu Formation volcanic rocks in the Tonghua area are 119.2 Ma in age, the Yingcheng Formation in the Jiutai area 113.4±3.1 Ma, the Jinjiatun Formation in Pinggang Town of Liaoyuan City and the Wufeng volcanic rocks in the Yanji area 103.2±4.7 Ma and 103.6±1 Ma, respectively. Combined with the data of recent publication on volcanic rocks ages; the Cretaceous volcanic events in southeastern Jilin Province can be tentatively subdivided into three eruption periods: 119 Ma, 113 Ma and 103 Ma. The result not only provides important chronology data for subdividing Mesozoic strata in southeastern Jilin Province, establishing Mesozoic volcanic event sequence, discussing geological tectonic background, and surveying the relation between noble metals to the Cretaceous volcanic rocks, but also offers important information of Mesozoic volcanism in northeastern China.
Sedimentation History of Neogene Lacustrine Sediments of Suŝeoĉka Bela Stena Based on Geochemical Parameters (Valjevo‐Mionica Basin, Serbia)
Authors: ŜAJNOVIĆ Aleksandra , SMIĆ Vladimir , JOVANĈIĆEVIĆ Branimir , CVETKOVIĆ Olga , DIMITRIJEVIĆ Radovan , GRUBIN Nenad
Published: September 2010

Abstract: Sediments of the western part of the Valjevo‐Mionica basin (Serbia) were examined both geochemically and mineralogically to explain, on the basis of their sedimentological characteristics, the causes of changes in their qualitative and quantitative composition. A total of 62 samples obtained from the drillhole at depths up to 400 m was investigated. Using correlation of the obtained data, six geochemical zones were defined, two of which being specially distinguished by their mineralogical, geochemical and sedimentological characteristics. The first one, upper zone A, consists of banded marlstones interbedded with clay and oil shales and is characterized by presence of analcite and searlesite. These minerals and very high contents of Na2O indicate sedimentation in alkaline conditions with increased salinity in arid climate. That provided pronounced water stratification, as well as higher bioproductivity in the basin and sedimentary organic matter preservation. Therefore, the zone A sediments are characterized by high organic matter contents of the type which provides good potential for production of liquid hydrocarbons. Another specific zone, zone F, contains sediments with very high MgO, K2O and Li concentrations. Their geochemical correlation, as well as almost complete absence of illite in this zone, indicates the presence of interstratified clay mineral type illite‐saponite (lithium‐bearing Mg‐smectite).
Temporo‐spatial Coordinates of Evolution of the Ordos Basin and Its Mineralization Responses
Authors: Chiyang LIU , Hongge ZHAO , Junfeng ZHAO , Jianqiang WANG , Dongdong ZHANG , Minghui YANG
Published: September 2010

Abstract: The Ordos basin was developed from Mid‐Late Triassic to Early Cretaceous, and then entered into its later reformation period since the Late Cretaceous. Its main body bears the features of an intra‐cratonic basin. The basin also belongs to a multi‐superposed basin which has overlapped on the large‐scale basins of the Early and Late Paleozoic. Currently, Ordos basin has become a residual basin experienced reformation of various styles since the Late Cretaceous. It's suggested that there were at least four obvious stages of tectonic deformations existing during the basin's evolution, dividing the evolution and sedimentation into four stages. The prior two stages were of the most prosperous, during which the lake basin was broad, the deposition range was more than twice larger than the current residual basin, resulting in major oil‐ and coal‐bearing strata. The two stages were separated by regional uplift fluctuations in the area. At the end of the Yan'an Stage, the depositional interruption and erosion were lasting for a short period of time. The third one is the Mid‐ Jurassic Zhiluo‐Anding stage, in which the sedimentation extent was still broad but the lake area was obviously reduced. In the Late Jurassic tectonic deformation was intensive. A thrust‐nappe belt was formed on the basin's western margin while conglomerate of different thickness were accumulated within the foredeep of the eastern side. The central and eastern parts of the basin were subject to erosion and reformation. A regional framework with “uplift in the east and depression in the west” took shape in the area west of the Yellow River. In the Early Cretaceous sediments were widely distributed, unconformably overlapping the former western margin thrust belt and the ridges on the northern and southern borders. There are abundant energy resources such as oil, natural gas, coal and uranium deposits formed in Ordos Basin. The main stages of generation, mineralization and positioning of the multiple energy resources have obvious responding connection and close coupling relationships with those of the Mesozoic and Cenozoic evolution and reformation in Ordos Basin.
Cucina Roma
Authors: CHINSAM NATALIE , SPRAAKMAN GARY
Published: September 2010

Focusing on a client organization wanting to outsource its food services, this case provides the opportunity for students to analyze the issues from the perspectives of both the outsourcing company and the food service company (Cucina Roma). The client wants employees to increase their use of the café in order to improve employee morale, productivity, and work‐life balance. The Cucina Roma case requires students to use a budget to dynamically plan tactics that will encourage employees to use the company café. Students are tested for budgeting and planning, both quantitatively and qualitatively. The challenge for students is to convert the qualitative analysis into numbers.
Cultural Preferences in Hotel Guestroom Lighting Design
Authors: Park Nam–Kyu , Pae Joo Youl , Meneely Jason
Published: September 2010

This study examined North American and South Korean preferences for different lighting conditions in a hotel guestroom. A sample of 87 North Americans and 88 Koreans ( N = 175) rated their preference for different intensities and color temperatures of light within a digitally generated hotel guestroom design. A mixed between–within analysis of variance ( Kuehl, 1999 ) evaluated three dependent variables (preference, arousal, and pleasure) against three independent variables (two culture groups × two light colors × two light intensities). Findings indicated that North American subjects preferred the hotel guestroom with low intensity and warm color lighting the most, whereas the Korean group preferred high intensity and warm color lighting the most. North American participants also perceived dim lighting as more arousing than bright lighting, whereas Korean participants perceived bright lighting as more arousing than dim lighting. Overall, the findings suggest that design criteria for hotel guestroom lighting should be revised to account for distinct cultural differences.
The Price of Democracy: Vote Buying and Village Elections in China
Authors: Kennedy John James
Published: September 2010

Local elections have been occurring in most villages for over a decade in rural China, and competitive elections are one of the key indicators of the democratic process. Indeed, competition is an important aspect of any democracy, and it increases the value of a villager's vote—so much so that in some villages, a farmer's vote can be worth a small fortune. As village elections become more competitive, reports of vote buying are on the rise, and a number of journalists and academic researchers have condemned this growing practice in rural China. Accordingly, vote buying subverts democratic development and hinders democratization efforts. However, vote buying has a long history in well‐established democracies, such as the United States and Great Britain. Rather than subverting democratization, vote buying can be viewed as part of the process or the price of democracy. While policies and laws are needed to control vote buying in the long run, initially it is a positive indicator that voting is an important and valuable process in rural China.