bluuebunny/crossref_metadata_2025_split huggingface dataset:
Model for Quantitatively Estimating Marine Biogeographic Provinciality—A Case Study of the Permian Marine Biogeography Provincialism
Authors: Guangrong Shi 
Published: September 2010

AbstractThe relationship between the number, position and orientation of lithospheric plates and marine biogeographic provinciality may be quantified since the spatial distribution of organisms is primarily controlled by latitude—related temperature gradients and geographical barriers— two dynamic biogeographic determinants whose variation is closely related to the spatial disposition of continents and oceans. This paper modifies Schopf's (1976) model for quantitatively estimating shallow marine provinciality in recognition of latitude–related temperature gradients as the primary biogeographical factor. A test of the modified model against modern marine zoogeography reveals high consistency between them. Using this modified model and the Permian palaeogeographical reconstruction maps of Scotese and McKerrow (1990), fifteen shallow benthic marine provinces are estimated to be Early and Late Permian in age respectively. A comparison of the estimated Permian marine provinciality with previously recognised empirical provincial patterns reveals a high degree of congmity, which may imply that there existed moderate to high latitudinal thermal gradients during the Permian, a level probably similar to that of the present world.
On the Carboniferous Sequence Stratigraphy in the Tazhong Area, Xinjiang — A Model of the Sequence Stratigraphy Framework of Intracratonic Depressional Basins
Authors: Jianhua Guo , Yunfu Zeng , Yonghong Zhai , Zhenzhong Gao 
Published: September 2010

AbstractThe Carboniferous prototype sedimentary basin in the Tazhong (Central Tarim basin) area is recognized as a compressive intracratonic depressional one. Three type I sequence boundaries and three type II sequence boundaries can be identified in the Carboniferous System, which can accordingly be divided into five sedimentary sequences. These sequences possess stratigraphic characters of the standard sequence and correspond to the depositional stratigraphic unit of a third–order eustatic cycle. They can be regionally or globally correlated with each other. The framework of sequence stratigraphy of the intracratonict basin in the study area distinctly differs from that of the passive continental–margin basin in the lack of depositional systems of early–middle lowstand, poor development of the deeply incised valley and condensed section of the maximum sea—flood, good development of type II sequence boundaries and coastal plain depositional systems coexisting with shelf–type fan deltas under wet climatic conditions, which consequently led to the formation of a paralic lithofacies framework.
Quantitative Tectonic Markers of Large Coastal Earthquakes in Fujian, Guangdong, Taiwan and Hainan —with a Discussion of Qualitative Indicators
Authors: Fuzhi Bi , Youshen Yuan 
Published: September 2010

AbstractThis paper expounds the quantitative tectonic indicators and some qualitative indicators of large earthquakes in the coast areas of Fujian, Guangdong, Taiwan and Hainan. The main quantitative indicators include uplift amplitude of the Moho, Quaternary and Late Holocene coasts. The paper also gives a brief account of the research method on quantitative indicators of surface uplifted zones. Taiwan is a famous neotectonic zone and an area of large earthquakes in the world. There is only one large–earthquake area in each of Fujian, Guangdong and Hainan Provinces. Along the coast large earthquake areas there are certainly many remains of crustal activity. Among these remains, coast activity, taking the sea level as the accurate marker horizon, can determine not only the amplitude of coastal elevation and subsidence in a certain period, but also the cycle and rate of positive or negative movements.
Experimental Study of the Melting Reaction and Genetic Mechanism of Mineral Phase Transformation in Granulite Facies Metamorphism
Authors: Fulai Liu , Qihan Shen , Yuansheng Geng , Xuechun Xu , Rui Ma 
Published: September 2010

AbstractThe high–temperature and high–pressure experiment on natural block rock indicates that dehydration–melting of hydrous biotite (Bi) and partial melting of felsic minerals in garnet–biotite–plagioclase gneiss are mainly controlled by temperature, while mineral phase transformation is not only controlled by temperature–pressure conditions but also genetically associated with hydrous mineral dehydration–melting and partial melting of felsic minerals. According to the characteristics of biotite dehydration–melting and garnet transformation reaction, three stages may be distinguished: (1) when the experimental temperature is 700°C, biotite transforms to ilmenite (Ilm) + magnetite (Mt) + H2O and garnet to magnetite (Mt); (2) when the temperature is 730–760°C, biotite is dehydrated and melted and transformed into K2O—rich melt + Ilm + Mt, and garnet, into hypersthene (Hy) + cordierite (Crd); (2) when the temperature is up to or higher than 790°C, biotite is dehydrated and melted and transformed into melt + Hy + Ilm + Mt, and garnet, into the hypersthene (Hy) + spinel (Sp) + cordierite (Crd) assemblage. The melt proportion and its evolutionary characteristics are mainly controlled by dehydration–melting of hydrous minerals and partial melting of felsic minerals besides P–T conditions; In addition to the traditional solid + solid (or fluid) reaction and dehydration—melting reaction, the metamorphic reaction involving melts (reaction between unmelted minerals and melts) is one of the most important reactions in granulite facies metamorphism and its attendant remelting (or regional migmatization). This experiment may provide dependable experimental data for an in–depth study of the genetic mechanism of mineral assemblage evolution and its geological dynamic significance in granulite facies metamorphism of the studied area.
Stable Carbon Isotope Geochemical and Hydrochemical Features in the System of Carbonate–H2O–CO2 and Their Implications—Evidence from Several Typical Karst Areas of China
Authors: Zaihua Liu , Daoxian Yuan , Shiyi He 
Published: September 2010

AbstractOn the basis of hydrochemical observation and experimental calculation, the features of stable carbon isotope geochemistry in the karst dynamic systems of the Guilin Karst Experimental Site, Huanglong Ravine and Wujiangdu Dam Site are summarized in this study. Furthermore, an attempt has been made to solve several geochemical problems, such as the origin of CO2 in the system, kinetic fractionation of carbon isotopes during calcite deposition, hydrochemistry and formation of tufa, and carbon—14 dating of tufa of hydrothermal origin. The results show that three kinds of karst dynamic system can be distinguished: (1) the shallow system, such as the Guilin Karst Experimental Site, in which soil CO2 provides the an active agent for karst processes; (2) the geothermal system, such as the Huanglong Ravine, in which metamorphic or/and juvenile CO2 is the source of activity for karst; (3) the anthropogenic system, such as the Wujiangdu Dam Site, in which the stable carbon isotope geochemical and hydrochemical features have been greatly affected by human activity.
Changchengite—A New Iridium Bismuthide–Sulphide from the Yanshan Mountains
Authors: Zuxiang Yu 
Published: September 2010

AbstractChangchengite occurs in chromite orebodies in dunite and in platinum placer deposits in chromite orebodies nearby. The mineral occurs as massive aggregates or veinlets on margins of iridisite (IrS2) and replaces it. Opaque. Lustre metallic. Colour steel–black. Streak black. Hm = 3.7. VHN20= 165 kg/mm2. Isotropic. Cleavage none. Density 11.96 g/cm3. Seven electron microprobe analyses give the following mean chemical results (wt. %): S 7.2, Cu 0.3, Te 0.4, Ir 41.2, Pt 2.8 and Bi 47.3 with total 99.1. The simplified formula is IrBiS. The strongest X–ray powder diffraction lines (hkl, d, f) are 210, 2.75 (70); 211, 2.51 (60); 311, 1.860 (100); 440, 1.090 (50) and 600, 1.027 (50). The X–ray powder diffraction pattern is similar to that of mayingite. After the diffraction data are indexed the mineral is determined to be cubic. The space group is P 213 with a = 0.6164(4) nm, V = 0.2342 nm3 and Z = 4.
Extreme Mantle Heterogeneity beneath the Jingpohu Area, Northeastern China—Geochemical Evidence of Holocene Basaltic Rock
Authors: Zhaochong ZHANG , Zong LIN , Zhaonai LI , Shucai LI , Zhaomu LI , Xianzheng WANG 
Published: September 2010

AbstractHolocene basaltic rocks of the Jingpohu area are located in the “Crater Forest” and Hamatang districts to the northwest of the Jingpohu Lake. Although there is only a distance of 15 km between the two districts, their petrological characteristics are very different: alkaline olivine basalt without any megacrysts in the former, and leucite tephrite with Ti‐amphibole, phlogopite and anorthoclasite megacrysts in the latter. On the basis of their geochemical characteristics, the two types of basaltic rocks should belong to weakly sodian alkaline basalts. But leucite tephrite is characterized by higher Al2O3, Na2O and K2O, higher enrichment in light rare earth elements (LREE) and large ion lithophile elements (LILE), lower MgO and CaO, compatible elements and moderately compatible elements and lower Mg*values and Na/K ratios in comparison with alkaline olivine basalt. However, the two types of basaltic rocks have similar Sr, Nd, Pb isotopic compositions, which suggests that the mantle beneath the Jingpohu area was homogeneous before undergoing some geological processes about 3490 years ago. As the activity of the mantle plume led to different degrees of metasomatism, extreme mantle source heterogeneities occurred beneath the Jingpohu area. In comparison with alkaline olivine basalt, the leucite tephrite was derived from the more enriched mantle source region and resulted from strong metasomatism.
Evolution of Mesozoic Volcanic Basins and Red Basins in the Gan‐Hang Tectonic‐Volcanic Metallogenic Belt
Authors: Xinpu ZHANG 
Published: September 2010

AbstractThis paper mainly proposes six major regional geological events in the active continental‐margin mantle uplift zone and discusses the oscillation nature of the evolution of Mesozoic volcanic basins and red basins, origin of erosion in the late stage of red basins and mechanism of volcanism.
Palaeoclimatic Indicators of China's Quaternary Saline Lake Sediments and Hydrochemistry
Authors: Mianping ZHENG , Yuanyi ZHAO , Junying LIU 
Published: September 2010

AbstractIn this paper the authors classify saline lake sediments into the cold, warm and eurythermal phases, reveal the consistency between the zoning of hydrochemical types of modern saline lake water and climatic zoning and give climatic parameters under the conditions of typical cold phase (mirabilite and natron), warm phase (thenardite) and slightly warm phase (bloedite) saline lake deposition.
Quaternary Climate and Environment in the Lop Nur, Xinjiang
Authors: Mili WANG , Qingyu PU , Chenglin LIU , Yongzhi CHEN 
Published: September 2010

AbstractSince the middle Early Pleistocene (1.20 Ma B.P.), the desert steppe climate and environment have predominated in the Lop Nur area, Xinjiang, characterized by warm humid epochs interrupted by dry cold intervals. The grain‐size and magnetic susceptibility curves record 30 climatic oscillations, each with a ca. 40 ka cycle, in the area since 1.2 Ma B.P., which reflects the controlling effects exerted by the astronomic factor on the environment. The Quaternary sedimentary environment in the Lop Nur gradually changed from a fresh lake through a brackish lake to a saline lake, showing a spiral evolution, and finally it evolved into a playa.
Rb and Sr Geochemical Characterization of the Chinese Loess Stratigraphy and Its Implications for Palaeomonsoon Climate
Authors: Jun CHEN , Yongjin WANG , Yang CHEN , Lianwen LIU , Junfeng JI , Huayu LU 
Published: September 2010

AbstractConcentrations and distributions of Rb and Sr in loess and palaeosol samples from the Luochuan profile have been studied, in grain‐size fractions and chemical forms. Results show that Rb is quite rich in the fraction of less than 2 μm, and exits only in the residual phase, while Sr is distributed in sand and silt fractions, occurring in the residual and carbonate phases. Therefore, variations of the concentrations of Rb and Sr in loess and palaeosols are closely related not only to dustfall compositions depending on winter monsoon wind strength but also to summer monsoon‐induced pedogenic intensity. This indicates that variations of Rb/Sr ratio in Chinese loess sequences represent cyclic alternations of East Asian summer and winter monsoon climates on the orbital time‐scale. Variations in Sr concentrations along the sequence bear a high similarity to the oxygen isotope record of the deep sea sediments over the past 2.5 Ma, whereas variations in Rb concentrations are in good agreement with the record of magnetic susceptibility determined with the duplicated samples from the same profile. This suggests that (1) the high‐latitude ice volume is responsible for East Asian monsoon variations and (2) the signal of magnetic susceptibility depends dominantly on pedogenesis in Chinese loess sequences.
Pb Isotope Study of Some Nonferrous Metallic Deposits in China
Authors: Wenxin XU , Minyang CHEN , Chunyong PANG , Heng LI 
Published: September 2010

AbstractBased on Pb‐Pb isochron data of more than 40 Precambrian polymetallic deposits, the authors consider that there are four mineralization periods for the Precambrian copper deposits in China, and the major copper deposits were formed at about 1800 Ma; there are three mineralization periods for gold deposits formed from Archaean to Proterozoic. By studying hundreds of lead isotope data from some Mesozoic continental subvolcanic Cu and Ag polymetallic deposits and fine‐disseminated gold deposits, the authors found that the calculation based on the lead single‐stage evolution model or two‐stage evolution model cannot give the true ore‐forming ages but can provide more information about mineralization and material sources of the deposits.
The Mechanism of Groundwater Salinization and Its Control in the Yaoba Oasis, Inner Mongolia
Authors: Bingchen WANG , Hanxue QIU , Qian XU , Xilai ZHENG , Guanqun LIU 
Published: September 2010

AbstractThe arid area is one of the most concerned areas among the water resources researchers and economists. Northwest China will be an important developing region of China in the 21st century. Yaoba is a well‐irrigation oasis within this arid area, which is located in the Alxa area west of the Helan Mountains and next to the Tengger desert in the east. It has contributed greatly to the local stock raising and agriculture since its development in 1970. However, the groundwater which the oasis depends on to survive has been getting salinized gradually and more serious in recent years.A comprehensive study was carried out using the methods of groundwater environment isotope analysis, lithofacies and palaeogeography, calculations of water‐rock interaction and the existing form of chemical components in groundwater etc. It has been found that the salinization of groundwater is mainly caused by reinfiltration water solving the salt in soil which is deposited simultaneously with the sediments and accumulated in the vadose zone due to strong evaporation in the arid climate for the running of an irrigation scheme.The saline groundwater in the Taosu Lake area southwest of the oasis is preliminarily regarded as the main source of groundwater salinization. However, it has been found that the groundwater has great differences in the D, 18O, H3and NO3 concentrations with that in the oasis, that is, the former plays only a limited role in the salinization of groundwater in the oasis.The HST3D model (a computer code for the simulation of heat and solute transport in a three‐dimensional groundwater system) was used to simulate the TDS movement in the oasis. A good simulation result has been obtained with the mean simulation error of 4.7% and the simulation trend is reasonable. It is proved that there is 3.0–4.0times105m3/a of reinfiltrated irrigation water in 3 main spots in the oasis. The oasis irrigation manner, winter irrigation to wash salt, the increase of wheat planting area, and no amount limit to water users (the farmers) are the main factors for causing the increase of water consumption as well as the groundwater salinization. The control measures on the groundwater salinization should include the establishement of reasonable irrigation regulations, water use limitation measures, flood utilization project, saltwater discharge, sealing of the upper layers to prevent the saline water to enter the pumping wells.
A Study of Near‐ and Super‐Critical Fluids Using Diamond Anvil Cell and in‐Situ FT‐IR Spectroscopy
Authors: Shumin HU , Ronghua ZHANG , Xuetong ZHANG 
Published: September 2010

AbstractThe phase relation and solution structure of water and NaCl aqueous solution have been observed and examined by using the hydrothermal diamond anvil cell (HDAC) at elevated temperatures and pressures and the in situ FT‐IR spectroscopy. The temperature of observations ranges from 25 to 850°C and the pressure up to 10 or 30 kb. At first, we observed the phase transition process from halite+liquid+vapour (H+L+V) to L+H, then to L (or supercritical fluid, SCF), and another path: H+L+V→L+V→L (or SCF) in heating process. By means of the visual microscope, the authors found that in the L+V immiscibility field L+V exhibits an ordered structure, i.e. a large visual cluster of solvent around ions. The liquid phase is manifested by vapour bubbles. When phase transitions are observed, the authors examined their infrared spectra by using the FT‐IR microscopy simultaneously. In the case of the phase transition from liquid (L) to liquid + vapor (L+V) immisciblity field of NaCl solutions, a sudden change (strong frequency shift) of infrared spectra of the aqueous solution is observed near the critical temperature of water as the temperature is raised from 25 to 650°C. The frequency of the maximum intensity of OH symmetric and asymmetric vibration varies with respect to temperature. The sharp peak of the OH stretching vibration of the maximum intensity appears in an interval from 300 to 400°C. It is indicated that the hydrogen bonding network is weakened and broken at last near the critical point of water, which causes the aqueous solution to become more associated. Besides, a pressure indicator (a mineral or compound) was introduced to the HDAC.
A Study of Devonian Reefs from Southern China
Authors: Tianqiu HONG , Ming HUANG , FLAJS G. 
Published: September 2010

AbstractThree Devonian reefs (bioherms) from Yunnan and Guangxi, southern China, are studied in detail. Six microfacies types are differentiated. Colonial rugose corals (Columnaria, Disphyllum and Hexagonaria) at Qujing, tabulate corals (Alveolites) with massive stromatoporoids (Actinostroma and Stromatoporella) and sponges at Panxi, and massive stromatoporoids (Actinostroma, Trupetostroma and Stromatoporella) at Yangshuo belong to the most important reef builders. All the three reefs studied clearly reveal a successive evolution history. They developed on the carbonate banks, shallow carbonate platforms and platform margins in the Late Givetian and terminated in the Frasnian due to sea‐level falls related to local uplifts of platforms. This coincides with a eustatic fall of relative sea level at the Frasnian/Famennian transition.
Sedimentary Environments of the Cangfanggou Group in Junggar Basin, Xinjiang, in Response to Climate and Tectonic Regime
Authors: Zhanghua LOU , Rong ZHU , Zhonghua TANG , Zhigang LIU , Xiafei ZHAO , Zhongcai CHEN 
Published: September 2010

AbstractDetailed studies of petrology, palaeocurrent direction, palaeogeomorphology and palaeohydrodynamics have been conducted for the Permian‐Triassic Cangfanggou Group in the foredeep of the Bogda Mountains in the southeastern Junggar Basin, Xinjiang. Sedimentary environments and facies of alluvial fans and pebbly braided rivers, sandy braided rivers, meandering rivers, low‐sinuosity rivers, swamps and fresh‐water lakes are recognized in the group. Climate and tectonics of source areas strongly controlled the evolution of the sedimentary environments and facies in the foredeep. The block faulting in the Bogda Mountains increased the ground slope, which led to a drastic increase in the grain size of the sediments. Humid climate, being beneficial to plant growth, would provide protection of channel banks and at the same time weaken chemical weathering in the source area, thus large amounts of clay materials are available for the formation of clay plugs. As a result, stable banks and meandering river belts are formed. Conversely, increasing aridity would strengthen mechanical weathering and reduce the number of clay plugs. Besides, plants would diminish gradually and channels would become more mobile. In this case the decrease of transported clay materials would reduce the stability of the bank and result in a wider and shallower channel. Therefore, humid climate is beneficial to the formation of meandering rivers even if there is strong block faulting in the source areas and the ground slope is very large. As aridity further increases, plants would diminish and vanish at last, the meandering rivers prevalent under humid climate conditions would be transformed to low‐sinuosity rivers even if the ground is gentle and the land is tectonically stable. And as the climate became more arid and the source area uplifted intensively to provide more sedimentary materials, low‐sinuosity rivers would be transformed to braided ones quickly, and wedge‐like sedimentary bodies of the braided rivers would then advance towards the lower reaches. The increasingly arid climate led to prevailing mechanical and diminishing plant protection to the banks. Both active tectonic regime and humid climate resulted in very shallow and mobile channels, i.e. a braided river system.The climate plays an important role in the evolution of rivers and lakes. The sinuosity and braiding parameters of channels are a result of complex interaction between climate (clay material supply, plant protection of the banks, flood events and so on) and tectonic regime (lithology of the source area, slopes and so on). Both factors can be estimated by sedimentological studies in the foothill belt.