bluuebunny/crossref_metadata_2025 huggingface dataset:
Mechanical Research on Binucleus‐Type Vortex Structures
Authors: Zuoxun Zeng
Published: August 2010

Abstract A new type of vortex structure—binucleus‐type vortex structure—is presented in this paper. It is characterized by two nuclear columns which distinguish it from uninucleus‐type vortex structure. The vortical surfaces of the structure are commonly s‐ shaped and reversed s‐ shaped and subordinately of elliptic and hyperbolic shape, and sometimes turbine‐like surfaces are observed.

On the basis of field structural studies, a mechanical model of rotation around a binuclear column of crustal materials is presented in the paper. Burgers viscoelastic solutions of the stress field and deformation field of this structural type have been obtained using the principle and method of rheology, and simulation experiments have been performed. The results of the theoretical calculation and experiments indicate that the proposed mechanical model is applicable.
Investigation of a New Exsolved Cu‐Fe‐S Phase in “Abnormal Sphalerite”
Authors: Jiuling Li , Su Wang
Published: August 2010

Abstract A new exsolved copper‐iron‐sulfur phase in sphalerite has been found in the Dajing cassiterite‐sulfide copper‐silver‐tin deposit, Inner Mongolia, China. After investigating the optical properties, chemical composition, crystal structure and exsolved characters of the exsolved phase, the authors present important evidence for its being a new exsolved copper‐iron‐sulfur phase mineral. Its formation mechenism is discussed in considering heating experiments, phase equilibrium data and the geology of the deposit.
The Boundary Between Gondwana and Pacifica and the Suturing Ages of Their Allied Terranes in Southwestern China1
Authors: Fuxiang Guo
Published: August 2010

Abstract Two terranes formed since the Late Palaeozoic can be distinguished in southwestern China. One is characterized by the Permo‐Carboniferous ice‐rafted marine gravel‐bearing clastic formation and the cold‐water fauna of the Gondwana facies, including the Gangmar Co, Lhasa, Sa ' gya, Tengchong and Baoshan terranes and the other is marked by the Upper Palaeozoic of the Yangtze type with the Cathaysian flora and the Pacific‐type fusulinids, comprising the Changning‐Menglian, Shuangjiang‐Lancang, Qamdo and Bayan Har terranes. The Longmu Co‐Shuanghu‐Dêngqên‐North Lancang River‐Kejie‐Mengding suture zone between the two groups of terranes is the boundary between Gondwana and Pacifica in southwestern China. On the grounds of the sedimentary formation and successive southwestward migration of the Asian nonmarine Jurassic‐Cretaceous endemic bivalves, the ages of the suture and some terranes to the southwest of the suture zone are discussed. The Baoshan terrane and the Nyainrong‐Sog terrane in the Lhasa composite terrane were firstly pieced together with the Asian continent in the early Early Jurassic. The northern Tibet‐western Yunnan microplate, including the Gangmar Co, Lhasa and Tengchong terranes, collided with the Asian continent at the end of the Early Cretaceous Neocomian.
Geochemistry of a Rapakivi Granite Suite in a Proterozoic Rift Trough in Beijing and Its Vicinity
Authors: Jianhua Yu , Huiqin Fu , Fenglan Zhang , Meisheng Guan
Published: August 2010

Abstract Controlled by E‐W‐trending faults, a Proterozoic (1.4‐1.8 Ga old) rapakivi granite suite was intruded in Beijing and the area to its east (within Hebei Province), forming three parallel belts of igneous rocks. The isotopic, trace element and rare earth element geochemical data of a bimodal rock association made up of anorthosite, gabbro and alkali basalt and olivine‐bearing quartz‐syenite, rapakivi granite and trachyte as well as potassic A‐type granites and anorogenic granites— all suggest that there exists an incipient rift in the study area. Fractional crystallization of a mixed magma formed by the magma derived from the upper mantle and the magma derived by small degrees of fusion of the lower crust produced anorthosite cumulates. The water‐deficient granitic magma was differentiated into a subalkaline series. When the fractional crystallization was incomplete, rhythmic eruptions took place.
The Thermal Structure of the Upper Mantle in Eastern China—Inferred from the Petrological Model
Authors: Jinfu Deng , Hailing Zhao
Published: August 2010

Abstract Cenozoic basalt in eastern China contains abundant ultramafic xenoliths which are specimens of pyrolites released during basaltic magma eruption. A total of 405 P‐T data of pyroxene in the ultramafic rocks have been collected, which present a more precise pyroxene geotherm. The average geothermal gradient in the upper mantle represented by the pyroxene geotherm is about 3.3°C / km, which is much less than that derived from the conductive thermal model (≡ 14°C / km), implying the great significance of convective heat transfer. The calculation shows that the contributions of convective and conductive heat transfers are 79% and 21%, respectively. The perturbation in the thermal structure of the upper mantle is an important manifestation of the tectonothermal event of Cenozoic continental rifting and intense basaltic volcanism in eastern China. Based on the pyroxene geotherm and its comparison with the current geothermal field derived from the measurements of the surface heat flows, it is suggested that the Moho may be a secondary thermal boundary. The current geothermal field and the thermal structure of the lithosphere in eastern China may mainly reflect the result of the tectonothermal disturbance in the Neogene‐Quaternary, in other words, the lithosphere has just begun to cool.
Mineralogy and Mode of Occurrence of Gold, Silver and Bismuth of the Caijiaying Lead‐Zine‐Silver Deposit, Hebei Province
Authors: Dianhao Huang , Xiaoshi Ding , Chengyu Wu , Changjiang Zhang
Published: August 2010

Abstract The deposit under study is a hydrothermal filling‐metasomatic vein type lead‐zinc‐silver deposit, in which gold and silver can be recovered as by‐products. These metals mainly occur as microgranular native gold, electrum, stephanite, acanthite, pyraragyrite, freibergite, and native silver. Gold minerals tend to be associated with galenobismutite, native bismuth and unnamed Bi2Te. They are either enclosed in pyrite, marmatite, iron‐bearing sphalerite and galens or fill the microfissures of these minerals. Silver minerals usually occur in cleavages or fissures of galena, marmatite and pyrite, but are not associated with gold and bismuth minerals. Gold and silver mineralizations occurred later than lead and zinc, while the silver mineralization was preceded by that of gold.
The Middle Devonian Bimodal Association of Volcanic Rocks in the Northern Area of East Junggar, Xinjiang
Authors: Baofu Han
Published: August 2010

Abstract The Middle Devonian volcanic rocks in the northern area of East Junggar, located between the Ertix and Ulungur rivers of northern Xinjiang, may be divided into basic and acid ones. It is evident that a compositional gap exists between the two groups so that the volcanic rocks are not in line with a calc‐alkaline series because the intermediate rocks are absent in the area. The fact shows that the volcanic rocks are a typical bimodal association. The formation of the bimodal association of volcanic rocks in the area was closely related to continental rifting or continental extension in the Middle Devonian. In such a tectonic setting, magmas were first produced by partial melting of the mantle. Where crustal thinning was greater, the magmas ascended and erupted on the surface directly so that the basic volcanic rocks formed, but olivine and / or partial pyroxene fractionation occurred in the magmas during their ascent through the thinning crust. On the other hand, where crustal thinning was less, ascending mantle‐derived magmas reached the lower crust and accumulated there, resulting in partial melting of the lower crust and thus giving rise to the contaminated magma which was consolidated as acid volcanic rocks on the surface.
Clinopyroxenes in Kimberlites of China
Authors: Zhenxin Dong
Published: August 2010

Abstract The author studied the grain size, shape, colour, altered coat, mineral species, chemical composition, end‐ member components and infrared spectra of clinopyroxenes occurring as megacryst, macrocryst and groundmass minerals, intergrowths with pyrope and ilmenite and minerals in deep‐seated xenoliths and inclusions in diamonds in kimberlites of China. The clinopyroxenes under study were compared with megacryst clinopyroxenes in basalts and minerals in their deep‐seated xenoliths and clinopyroxenes in lamproites and minettes. The coexisting clinopyroxene‐pyrope pair was studied. Besides the author also studied the origin of clinopyroxenes in kimberlites, P‐T conditions for their formation and their reflected tectonic environments of the kimberlite formation. He suggests that this mineral is an indicator for diamond exploration.
Discovery of the Changtu Fauna in the Xia' ertai and Hulan Groups in Liaoning and Jilin and Its Significance
Authors: Xiaoliang Liu , Congyun Chen , Xuezeng Yang , Sen Yang , Jiongfei Zhang , Yuhua Gao
Published: August 2010

Abstract The Ordovician Changtu Fauna is recently discovered in the Xia' ertai and Hulan Groups in northern Liaoning‐central Jilin. The fauna, containing 10 genera and 14 species (including 3 new genera, 9 new species and an unidentified species), is closely related in evolution with the Early Cambrian Qinghezhen Fauna. The discovery of this fauna is significant to the study on the age of the strata, Ordovician biostratigraphy and geological evolution of the tectonostratigraphical terrane on the northern margin of the Sino‐Korean plate.
The Orogeny in the Altaides1
Authors: Guosheng Qu , Guoqi He
Published: August 2010

Abstract Studies of the deformation styles, formation types and isotopic age data indicate that the Altaides has successively experienced 5 stages of orogeny: (1) the Kanas orogeny forming the angular unconformity between the Baihaba Formation (O3) and the Habahe Group (Z‐O2); (2) the Daqiao orogeny (S3‐D1‐2) giving rise to the early Hercynian quasi‐aulacogen extensional continental crust of the area; (3) the Altay orogeny (middle‐ late Hercynian) leading to the oblique intracontinental collision and the formation of large shear arc‐shaped thrust system and representing a strong orogeny stage; (4) the pan‐Altay orogeny (latest Hercynian‐Indosinian) resulting in the uplifting and erosion of the mountains as a whole; (5) the Himalayan movement causing the rejuvenation of fault systems and block uplift of the Altaides since the Cenozoic.
The Evolution of Alpine Ultramafic Rocks and Partial Melting of the Upper Mantle1
Authors: Peisheng Bao , Xibin Wang , Ziguo Hao , Genyong Peng
Published: August 2010

Abstract Ultramafic rocks of Tibet and Xinjiang are the products of partial melting of the upper mantle. The evolution of their mineral composition is marked by two parallel evolutionary series: one is the progressive increase of the 100 Mg / (Mg+Fe2+) ratio of silicate minerals in order of lherzolite?harzburgite?dunite, i.e. the increase in magnesium; the other is the increase of the 100 Cr/(Cr+Al) ratio of accessory chrome spinel in the same order, i.e. the increase in Chromium. The above‐ mentioned evolutionary trends are contrary to that of magmatic differentiation. The evolution of fabrics of ultramafic rocks is characterized by progressive variation in order of protogranular texture? melted residual texture, symplectic texture and clastophyritic texture? equigranular mosaic texture and tabular mosaic texture. Experiments of partial melting of lherzolite have convincingly shown that the evolution of Alpine ultramafic rocks resulted from the partial melting of pyrolite. Various subtypes of them represent different degrees of partial melting. The vertical zoning marked by more basic rocks in the upper part and more acid rocks in the lower actually belongs to the fusion zoning of pyrolite.
Features of Geophysical Fields and Geodynamics of the China Sea
Authors: Guangding Liu
Published: August 2010

Abstract During 1960–1990, an extensive geological‐geophysical investigation was carried out in the marine areas of China. According to the materials obtained, the “Geological — Geophysical Serial Maps of the China Seas and the Adjacent Areas (1:2,000,000 )” was compiled. In fact, it is a systematic summary of the geological and geophysical work of the China Seas in the past 30 years.

In this paper, the author explains the guiding thought and methodology of the compilation of the serial maps, and then briefly discusses the characteristics of geophysical fields and geodynamics, stratigraphy, tectonics and magmatism.
Tectonic Interpretation of the Earthquake Distribution in the Contiguous Continent of the United States
Authors: Zongjin Ma , Xianglin Gao , Qi Wang , Seeber L. , Armbruster J.
Published: August 2010

Abstract With increasing high‐quality geological and geophysical data it becomes clear that seismicity of the continents is characterized by linear patterns which are closely associated with tectonic features. The aim of this paper is to give reasonable interpretation for the earthquake distribution in the contiguous continent of the United States. Seismic lines and earthquake concentrated zones are defined, which reflect the characteristics of the continental seismotectonics. Similarities and differences in seismotectonics between the continental part of China and the contiguous continent of US are analysed. It is demonstrated that the spatial distribution of earthquakes can provide the information of the active structures in the earth's crust. The authors consider that the patterns of continental seismotectonics are not only controlled by the pre—existing tectonic frameworks and the current boundary dynamic conditions, but also possibly affected by dynamic factors of global tectonics at a higher level.
Burial Metamorphism of the Ordos Basin in Northern Shaanxi
Authors: Lifei Zhang
Published: August 2010

Abstract Burial metamorphism has been found in the Ordos basin of northern Shaanxi. On the basis of a rather intensive study of burial metamorphism of sandstone, it has been shown that the evolution from diagenesis to metamorphism involves four stages: cementation of clay minerals, regrowth of pressolved quartz and feldspar, cementation of carbonates and formation of laumontite. On that basis it has been put forward that the laumontite is formed by burial metamorphism of clay and carbonate minerals. According to the thermodynamic data of minerals, the conditions under which laumontite is formed are T<250°C and Xco2<0.17. High‐resolution SEM and TEM studies of clay minerals in mudstone show that there occur a mixed layer assemblage of bertherine and illite/chlorite and trapsformation from bertherine to chlorite. On that basis coupled by the X‐ray diffraction analysis the author suggests the following transformation of clay minerals during burial metamorphism: the earliest smectite‐kaolinite assemblage changes into the bertherine‐illite mixture with increasing depth, then into the illite/chlorite mixed layer assemblage and finally into dispersed individual illite and chlorite. The reaction of the transformation is:

smectite+kaolinite+K+ = illite+chlorite+quartz

According to the study of the oxygen isotope thermometry of the coexisting illite‐quartz pair, the temperature of the above transformation is lower than 180°C.
Geological Evidence for the Presence of the Emperor Event in China
Authors: Tongming Ge , Limin Fan , Jian Liu
Published: August 2010

Abstract The presence of the reversals of the geomagnetic field within the Brunhes is indicated by paleomagnetic stuides on Cenozoic volcanic rocks in the Leizhou Peninsula, loess strata and Quaternary marine sediments in the Pearl River Mouth basin in China. These regional reversals occured at 0.58±0.13 Ma, 0.45 Ma and 0.47‐0.48 Ma respectively according to the results of K‐Ar isotopic dating and climatostratigraphic and biostratigraphic analyses. The reversals equivalent to the Emperor Event is suggested.

The reversals revealed in different regions with various lithologic characters in China prove that the Emperor Event is a global reversal event rather than a geomagnetic excursion, and its confirmation will permit a precise definition of the Middle/Late Pleistocene boundary.
Seismic Activity and Fuzzy Comprehensive Evaluation of Crustal Stability in the Beijing Region
Authors: Qinghua Huang , Yinsheng Ma , Xinchu Song
Published: August 2010

Abstract This paper discusses the seismic activity in Beijing Municipality and its adjacent areas (which are referred to as the Beijing region in the paper). By using fuzzy mathematics, the factors controlling regional crustal stability are transformed into fuzzy information and then a model of fuzzy diagnosis is established. A fuzzy comprehensive evaluation of regional crustal stability in the Beijing region is made according to the seismic and geological conditions of the region.
Archaean Greenstone Belts in China
Authors: Baofeng Shen , Xiaoliang Peng , Hui Luo , Debao Mao
Published: August 2010

Abstract Chinese Achaean greenstone belts are mainly distributed along the northern and southwestern margins of the North China platform. In terms of their geological characteristics, the greenstone belts in China are comparable to those in other countries but at the same time have unique features of their own. In view of their geochemistry, the Chinese greenstone belts may be grouped into three types: the Jiapigou type, Qingyuan type and Xiaoqinling type. The greenstone belts were formed possibly in a rift‐type palaeo ‐ tectonic setting, similar to that of the modern island arc‐continental margin mobile belts.
Relationships Between the North China Plate and the Tarim Plate1
Authors: Tingyin Jinrong Jinkun Wang, Wang, Liu , Shizheng Wang , Jiahong Wu
Published: August 2010

Abstract The relationships and boundary between the North China and Tarim plates have been unclear for a long time; however, the two plates occupy a prominent position in the formation and evolution of the continental lithosphere of China. It is proposed that the Engger Us ophiolitic mélange zone discovered recently north of Alaxa is a typical suture between the two plates. The ophiolitic mélange zone is composed mainly of a mixture of fragments of ancient oceanic crust and sedimentary rocks of active and passive continental margins. The mélange may be divided into tectonic inclusions and matrix. The suture extends northeastwards into the Republic of Mongolia and probably westwards to meet the Altun fault. With the Engger Us ophiolitic mélange zone as the boundary the Alaxa area may be divided into two parts: the northern part (AN) belongs to the Tarim plate, while the southern part (AS) the North China plate. Geological evidence shows that the two plates were amalgamated in the Late Permian or a bit later.
The Yagan Metamorphic Core Complex and Extensional Detachment Fault in Inner Mangolia, China1
Authors: Yadong Zheng , Qing Zhang
Published: August 2010

Abstract The article describes the characteristics of the Yagan metamorphic core complex, especially the associated detachment fault and various extensional structures in its footwall. The age of the complex is discussed in some detail as well. The basic features of the Yagan metamorphic complex (Jurassic in age) are similar to those of the metamorphic core complex (Tertiary in age) in the Cordilleran area; they are as follows: (a) mylonitic gneisses in the footwall, (b) chloritized sheared mylonitic rocks, (c) pseudotachylites and flinty cataclasites or microbreccias, (d) unmetamorphosed or epimetamorphic rocks in the hanging wall with a layer of fault gouges or incohesive fault breccia next to the detachment fault. In contrast to its Cordilleran counterpart, however, there are many extensional faults with different styles (from dactile low‐angle normal faults through brittle — ductile to brittle high — angle normal faults) in the footwall.
Trace Elements and Sr, Nd Isotope Geochemistry of the Lajimiao Norite‐Gabbro from the North Qinling Belt1
Authors: Shuguang Li , Yizhi Chen , Zongqing Zhang , Xiaojing Ye , Guowei Zhang , Anlin Guo , Hart S. R.
Published: August 2010

Abstract The Lajimiao norite‐gabbro complex, as a part of the ophiolites on the southern side of the North Qinling belt, consists of gabbro and norite‐gabbro. They were derived from different magma series: the gabbro was derived from tholeiitic magma series with higher TiO2, REE abundance and Fe3+ / Fe2+ ratio; norite‐gabbro was derived from calc‐alkali magma series with lower TiO2, Fe3+ / Fe2+ ratio and REE abundance and much lower HREE abundance, which suggests that the source of the norite‐gabbro magma was deeper and controlled by eclogite facies. Geochemical characteristics of both plutonic rocks are similar to those of island‐arc basalts, such as relatively high contents of Ba, Pb and Sr and relatively low contents of Nb, Zr and Ni.

The Sr, Nd isotopic characteristics of the Lajimiao norite‐gabbro complex are similar to those of ophiolites. Its 8Nd values are constant, about +2; whereas 8Sr values have wide variation from — 6.4 to +31.2 and positively correlate with Na2O, H2O+ and CO2 contents and the Fe3+ / Fe2+ ratio. The ɛNd—Nd / Th, ɛNd—La/Nb and ɛNd—Ba/Nb diagrams clearly show that there were significant components of terrigenous sediments in the mantle source of the Lajimiao norite‐gabbro complex. It suggests that large amount of sediments had been carried into the mantle by the subducted ancient Qinling sea plate during the Palaeozoic.
Late Permian‐Early Triassic Conodont Biofacies and Bioprdvinces in South China and Himalaya1
Authors: Jianxin Zishun Lipei Yao, Li, Zhan , Weicheng Hao
Published: August 2010

AbstractOn the basis of existing conodont data, the authors have studied the Late Permian‐Early Triassic cohodonts of different farms and biofacies in detail Five conodont biofacies are recognised, from shallow to deep water: 1.Hindeodusconodont biofacies 2. Pachycladina‐Parachirognathusconodont biofacies, 3.Gondolella‐HindeodusConodont biofacies, 4.Gondolella ‐ Neospathodusconodont biofacies, and 5.Xaniognathuscohodont biofacies. Considering the temporal and spatial changes of these conodont biofacies, 3 conodont bioprovinces have been divided. In light of the biofacies changes of each bioprovince, the authors also discuss, in this paper, the regularity of transgression‐regression cycles of eastern Tethys and their possible relation to the mass biotic alternation.
Geochemical Characteristics of the Ore ‐ forming Fluids of the Haigou Gold Deposit, Jilin
Authors: Yinqing Li
Published: August 2010

Abstract The quartz in the Haigou gold deposit contains a great abundance of three‐phase CO2‐NaCl‐H2O and two‐phase CO2‐rich inclusions, which are associated with two‐phase NaCl‐H2O ones. The ore‐forming fluids, which were rich in CO2, are classified into two types with two different sources: the high‐salinity CO2‐rich NaCl‐H2O fluid derived from magmatic hydrothermal solution, and the low‐salinity NaCl‐H2O fluid from ancient meteoric water. The optimum conditions for gold mineralization are 220‐300°C for the temperature, 4‐20 Mpa for the fluid static pressure, 1‐3 km for the mineralization depth, 2‐7 w (NaCl)/10‐2 for the fluid salinity, and 0.644 g/cm3 for the total density. The fluid was in a critical or supercritical state at the initial stage of mineralization, and it boiled and was unmixed with CO2 and NaCl‐H2O in the climax of mineralization, leading to the decomposition of Au‐chlorine complexes and the bulk precipitation of Au.

The type, association, homogenization temperature and composition (CO2/H2O value etc.) are the microscopic criteria for distinguishing the auriferous quartz vein from the barren quartz vein.
Cambrian‐Ordovician Deep‐Water Deposits in Southwest Jiangxi, China
Authors: Lei Ji
Published: August 2010

Abstract The Cambrian‐Ordovician rocks in southwestern Jiangxi are mainly composed of deep‐water deposits, in which 5 facies have been recognized: sandstone facies, sandstone ‐ mudstone facies, siltstone ‐ mud stone facies, mudstone (slate) facies, and chert facies. They are of turbidity current origin and are related to pelagic and hemipelagic deposits. In the light of facies distribution, the Cambrian‐Ordovician deposits can be classified into 3 facies associations formed in middle fan, outer fan and deep ‐ sea plain environments respectively. The 3 different orders of vertical cycles in the stratigraphic sequence are considered to be controlled by factors such as sea‐level fluctuation, basin subsidence and submarine fan progradation. The tectonic setting of the sedimentary basin is interpreted as passive continental margin based on the chemical composition analysis of the sandstone.
Permian Alkaline Granites in Central Inner Mongolia and Their Geodynamic Significance1
Authors: Dawei Hong , Huaizeng Huang , Yïjun Xiao , Haiming Xu , Manyuan Jin
Published: August 2010

Abstract Alkaline granites (Rb‐Sr ages 276‐286 Ma) occurring in the Bayan U1‐East Ujimqin belt at the southern margin of the Siberian plate originated in a tensional tectonic environment about 60 Ma earlier than the Late Devonian to Early Carboniferous collision between the Siberian and Sino‐Korean plates. They belong to post‐orogenic A ‐ type granites and may be used as an indicator of the end of the orogeny. At the northern margin of the Sino‐Korean plate, however, only late‐orogenic calc‐alkaline granites occurred during the late Caboniferous‐Permian, and alkaline syenites did not appear until the Late Triassic. The asymmetric magmatism at the margins of the two neighbouring plates might be controlled by the differences in size and mass of the two plates.
Dynamic Mechanism of Migmatization in the Dabie Complex, Northeastern Hubei, China1
Authors: Jianghai Wang , Wenhua Yang , Jinping Wu
Published: August 2010

Abstract On the basis of the detailed field work, compositions and contents of plagioclase and K‐feldspar, determination of ordering degree, statistical analysis of plagioclase elongation index, mass‐balance calculation and mineral spatial distribution and geochemistry, it is concluded that the migmatites in the Dabie complex are characterized by the presence of thermocenters. There are regular changes in mineral character in the migmatites from the centers outwards. The dominant genetic mechanism is anatexis and metasomatism, whose intensities decrease from the centers outwards. Finally, according to the simulated experiment on Liesegang' s rings and non‐linear dynamics (dissipative structure theory), the dynamic mechanism of migmatization is profoundly expouded as consisting of the early‐stage metasomatism induced by the thermal anomaly, the cardinal‐stage anatexis induced by the early‐stage matasomatism and finally the last‐stage post‐anatexis metasomatism.
Genesis of Coal Metamorphism of Late Palaeozoic Coals in the South of North China —A Further Approach to the Effects of Thermal Groundwater on Coal Metamorphism
Authors: Ningning Zhong , Daiyong Cao
Published: August 2010

Abstract The close relationship between the genesis of coal metamorphism and the evolution of the regional tectonic framework is expounded on the basis of an analysis of the geological factors causing the metamorphic zonation of the Late Palaeozoic coals in southern North China; in terms of the mechanism for the formation of palaeogeothermal anomalies, the effects of thermal groundwater on coal metamorphism is highlighted and a geological model for thermal groundwater metamorphism of coal established ; with the concept of the palaeogeotherm‐coal metamorphism system, the genesis of coal metamorphism is analysed according to the distribution pattern of three geological factors: heat source, heat‐carrier and channel, and heat‐collector.
A Study of Spatial Variability on Aquifer Hydraulic Conductivity K
Authors: Hetai Chaolunbagen, , Tingxi Liu
Published: August 2010

Abstract A structural analysis of K of an aquifer system in the study area is presented, and the main direction and degree of the variability of K are found by using the unstationary regionalized variable theory of geostatistics. Optimal estimation of K has been made by universal kriging method (UKM ). Both spatial variability distribution map and division map of K are given.
Oxygen Isotope Records of Core 8KL of the South China Sea and Sea‐level Change1
Authors: Jianxing Qian
Published: August 2010

Abstract Based on a comparison between the oxygen isotope records of benthic and planktonic foraminifers from core 8KL of the South China Sea and sea‐level change records derived from the Huon Peninsula, New Guinea, it is found that both records are very similar from 72 Ka B.P. to the present, especially for the benthic oxygen isotope record. The linear regression shows that δ18O changes (0.9995‰ for benthic foraminifers and 1.022‰ for planktonic foraminifers) are equal to 100 m in sea‐level fluctuation. After making temperature correction in the δ18O record of benthic foraminifers from 72 to 120 Ka B.P., the curve of sea‐level oscillation of the South China Sea since 186 Ka B.P. has been reconstructed. The lowermost sea‐level that occurred in the last glacial maximum and oxygen isotope stage 6 is approximately ‐ 130 m.
Aeolian Facies Belts in the Taklimakan Desert1
Authors: Baosheng Li , Guangrong Dong , Jiasheng Zhang , Sen Li , Heling Jin , Huizhong Chen , Xiangle Wen , Yao Wang , Yizhi Zhu
Published: August 2010

At least at the beginning of the last glacial epoch, the facies belts of dune sand, sandy loam and loess formed by winds had existed in the Taklimakan desert and areas south of it. There were no appreciable changes in the NE and NW wind systems and their wind forces that deposited dune sand, sandy loam and loess in the global cold stage since the last glacial epoch; accordingly no marked shifts of the boundaries of these aeolian facies belts took place. In the global warm stage since then, the climate in the Taklimakan desert and areas south of it became warm and dry, resulting in ablation of substantial volumes of ice and snow in their surrounding mountains and thus forming alluvial and diluvial deposits in the region. The alluvial‐diluvial actions, however, failed to change the general framework of aeolian facies belts.
Discovery of Early Proterozoic Carbon Isotope Shifts
Authors: Hua Zhong , Yongsheng Ma
Published: August 2010

Abstract The authors have detailedly and systematically studied the carbon isotopic composition of Early Proterozoic carbonate rocks. Samples which are all dolomicrite were taken from the Jianancun, Daguandong and Huaiyincun Formations of the Hutuo Group in Wutai County Shanxi Province, North China. A total of 209 samples were analysed for their carbon isotope compositions, and the mean sampling interval was 6.9 m. Carbon isotope analysis clearly shows δ13C shifts at the boundary between the Jian'ancun Formation and Daguandong Formation and near the boundary between the Daguandong Formation and Huaiyincun Formation. Like carbon isotope shifts at the Cretaceous ‐ Tertiary, Permian ‐ Triassic and Precambrian ‐ Cambrian boundaries, the discovery of δ13C shifts in the Early Proterozoic has important significance in further studies on Early Proterozoic biotic evolution, regional and global stratigraphic correlation, and carbon geochemical cycles.
The Palaeomagnetic Study of the Mineralization Age of Gold Deposits in the Xiong'ershan Area, Henan Province
Authors: Guanfu Wang , Zhihong Chen , Shiying Ding , Fugen Ren
Published: August 2010

Abstract Based on palaeomagnetic studies of the Precambrian gold deposits in the Xiong'ershan area, Henan Province, the authors infer that the ore‐forming processes of the Beiling alteration‐type gold ore deposit and the Dianfang breccia‐type gold ore deposit started in the Proterozoic, and was superimposed by later mineralization, whereas the mineralization age of the Jiguanshan quartz‐vein type gold ore deposit is Yanshanian.
The Best Natural Boundary: a New Concept Developed by Combining the Sequence Boundary with the GSSP
Authors: Shilong Mei
Published: August 2010

Abstract Through a detailed study of sequence boundaries, it is concluded that sequence stratigraphy is an independent regional and transitional stratigraphic system between local lithostratigraphy and global chronostratigraphy. Therefore, a new tripartite stratigraphic classification scheme has been proposed. By combining organically the concept of sequence boundaries with the GSSP, it is suggested that the GSSP should be chosen in a confórmale portion of a related sequence boundary, and the boundary established in light of this concept is defined as the Best Natural Boundary (BNB). The definition of the BNB points out the working area and stratigraphic level for the GSSP. By referring to a case study of the Permian Guadalupian/Lopingian boundary, the concept of the BNB has been elaborated in detail, and it is proposed that the BNB of the Guadalupian and the Lopingian lies between the Mesogondolella granti Zone and the Clarkma postbitteri Zone, which is also the sequence chronostratigraphic boundary between the Transpecos composite sequence (chronozone)and the UAA ‐ 1 composite sequence (chronozone).
Characteristics of Volcanic Rocks in the Shoshonite Province, Eastern China, and Their Metallogenesis
Authors: Dezi Wang , Qijiang Ren , Jiansheng Qiu , Kerong Chen , Zhaowen Xu , Jiahu Zeng
Published: August 2010

Abstract The shoshonite province in eastern China is characterized by extensive distribution (ca. 80000 km2) of Late Jurassic–Early Cretaceous (165–100 Ma) shoshonite series with subordinate high–K calc–alkali series. It was formed in a dominantly tensile stress field. In comparison with their analogues in island arcs and active continental margins in other countries, the volcanic rocks in the shoshonite province have their specific characteristics in petrology, mineralogy and geochemistry as well as related mineralization association, which are the comprehensive reflection of the special composition and structure of the mantle and crust of the province and the special Mesozoic regional tectonic setting.
Hydrogen and Oxygen Isotope Study on the Water–Rock Interaction of the Yinshan (Cu–) Pb–Zn–Ag Ore Deposit, Jiangxi Province
Authors: Ligang Zhang , Jingxiu Liu , Guixiang Yu , Zhensheng Chen
Published: August 2010

Abstract The δ18O values of vein quartz of different stages from the Yinshan ore deposit are constant around 16‰ and the calculated δ18OH2O values attain 8‰± the δ5DH2O . values of fluid inclusions in vein quartz are constant at about –60‰. From the surface down to 1200 m below the δl8O values of altered rocks gradually decrease from 15‰ ± to ll‰ ± . Various water–rock inversion calculations indicate that the ore fluids were formed by the interaction between meteoric water and phyllite at 350°C and the effective W/R value of around 0.1. When the water–rock exchange in the upper mineralization system took place, the effective W/R value increased to 5.0 or more. As a result, an evolution and mineralization model of a buffered open system with two–stage water–rock interactions is proposed in this study.
Behaviours of REE and Other Trace Elements During Pedological Weathering—Evidence from Chemical Leaching of Loess and Palaeosol from the Luochuan Section in Central China
Authors: Jun Chen , Hongtao Wan , Huayu Lu
Published: August 2010

Abstract The chemical leaching method is used for a systematic analysis of distribution characteristics of acid–soluble and acid–insoluble REE and other trace elements from the Luochuan loess deposits. The study shows that the acid–insoluble phase in loess and palaeosol is a stable component of old aeolian dusts and is characteristic of the provenance; the acid–soluble phase is the unstable component in the weathering pedogenic process and reflects rock–forming features after accumulation of aeolian dusts. The acid–insoluble REE and acid–soluble Sr and Pb can be used as geochemical indicators respectively to trace the provenance characteristics and the weathering pedogenic process.
Lower Jurassic Sequence Stratigraphy and Sedimentary Facies on the North Slope of Mount Qomolangma
Authors: Xiaoying Shi , Zhenyu Lei , Jiarun Yin
Published: August 2010

Abstract The Lower Jurassic is subdivided in ascending order into the Wulong, Kangdui and Yongjia Formations on the north slope of Mount Qomolangma, with a total thickness of 1362 m. They are thought to have been deposited respectively in the environments of the carbonate ramp fault–bounded basins and carbonate platform, with six sedimentary facies and six sub–facies. During the Early Jurassic, the Qomolangma area experienced strong faulting and subsidence, and was of a matured rift basin. The Lower Jurassic consists of eleven 3rd–order sequences, which can be grouped into three 2nd–order sequences and form a large transgressive–regressive cycle. The 3rd–order sequences and the corresponding sea–level changes recognized in the area can be correlated quite well with those set up in the western Tethys, and may have been caused by the eustatic fluctuations, while the 2nd–order sequences seem to be more closely related to the basement subsidence and the variation in sedimentary influx, indicating the evolution of the eastern Neotethys and the movement of the plates on its two sides.
AN INTRODUCTION TO SINGULAR PERTURBATIONS
Authors: MACGILLIVRAY A.D.
Published: August 2010

ABSTRACT. In this article we discuss the asymptotic analysis of so‐called singularly perturbed differential equations. We begin by discussing some very simple nonmathematical examples, and then proceed to two mathematical examples, namely, the well‐known example of Friedrichs and a problem of John Mahony's. The presentation is addressed primarily to those who may have had little or no previous experience with this particular type of problem. However, the author hopes others will find something of interest in the somewhat unusual approach we take.
NEW DEVELOPMENTS IN FOREST MODELING: CONVERGENCE BETWEEN APPLIED AND THEORETICAL APPROACHES
Authors: LISCHKE H.
Published: August 2010

ABSTRACT. Additionally to simulations, a mathematical analysis of ecological models could give insights into the system behavior. However, mathematical model analysis has only been performed for simple, abstract models, because models based on biological processes are too complex. Linking simple and detailed approaches could help to obtain mathematically tractable models which are based on physiological and ecological processes. This can be achieved either by extending simpler models with components of complex ones, or by a controlled simplification of complex models. Forest models ranging from models describing processes in organs of individual tress in three‐dimensional space to models averaging over all trees of an entire region, are reviewed, categorized by hierarchical level and represented in a general mathematical formulation. Possibilities and approaches of transitions between the approaches, namely linking of approaches and upscaling of individual based models are presented and discussed.
WEIGHT‐CONTROLLED RECRUITMENT OF THE ANCHOVY IN THE LATE LARVAL STAGE
Authors: PARDO OLIVIER , ARINO OVIDE
Published: August 2010

ABSTRACT. A formula for the rate of recruitment of the anchovy in the late larval stage is proposed. Recruitment is assumed to occur when the weight crosses a threshold value. The study is undertaken in the framework of a model of fish dynamics which is presented in the first part of the paper.
REGULATION OF A FISHERY: FROM A LOCAL OPTIMAL CONTROL PROBLEM TO AN “INVARIANT DOMAIN‘ APPROACH
Authors: TOUZEAU SUZANNE , GOUZË JEAN‐LUC
Published: August 2010

ABSTRACT. This study aims at regulating a fishery by reducing its catch and effort variations around a reference equilibrium point. A simple bioeconomic continuous time model is considered and the control variable acts on the rate of change of effort. Two approaches have been implemented: the first one is a local optimal approach that sets the problem in the classical linear‐quadratic framework; it is extended to an “invariant domain‘ approach, whose robustness constitutes a major advantage.
EFFORT SUBSIDIES AND ENTRY DETERRENCE IN TRANSBOUNDARY FISHERIES
Authors: QUINN JOHN , RUSESKI GORAZD
Published: August 2010

ABSTRACT. This paper analyzes a two‐stage game, based on the Gordon‐Schaefer model of the fishery, to examine the strategic entry‐deterring role for effort subsidies in noncooper‐ative transboundary fisheries. The game reveals that a country, whose domestic fleet has an effort cost advantage over a rival foreign fleet, may choose to subsidize domestic effort to the point that foreign entry in the fishery becomes unprofitable. Whether the outcome of the game is characterized by foreign entry deterrence or accommodation, and whether it is also characterized by a domestic effort subsidy or a tax, depends on domestic and foreign effort costs and the number of firms in each fleet. The various outcomes of the game analyzed here help to explain the persistence of subsidies in some world fisheries.
POPULATION‐LEVEL ANALYSIS AND VALIDATION OF AN INDIVIDUAL‐BASED CUTTHROAT TROUT MODEL
Authors: RAILSBACK STEVEN F. , HARVEY BRET C. , LAMBERSON ROLAND H. , LEE DEREK E. , CLAASEN NATHAN J. , YOSHIHARA SHUZO
Published: August 2010

ABSTRACT. An individual‐based model of stream trout is analyzed by testing its ability to reproduce patterns of population‐level behavior observed in real trout: (1) “self‐thinning,” a negative power relation between weight and abundance; (2) a “critical period” of density‐dependent mortality in young‐of‐the‐year; (3) high and age‐specific inter‐annual variability in abundance; (4) density dependence in growth; and (5) fewer large trout when pool habitat is eliminated. The trout model successfully reproduced these patterns and was useful for evaluating their theoretical basis. The model analyses produced new explanations for some field observations and indicated that some patterns are less general than field studies indicate. The model did not reproduce field‐observed patterns of population variability by age class, discrepancies potentially explained by site differences, predation mortality being more stochastic than the model assumes, or uncertainty in the field study's age estimates.
MEASURING THE COSTS OF REALLOCATING WATER FROM AGRICULTURE: A MULTI‐MODEL APPROACH
Authors: SUNDING DAVID , ZILBERMAN DAVID , HOWITT RICHARD , DINAR ARIEL , MacDOUGALL NEAL
Published: August 2010

ABSTRACT. Increasing demand for water by environmental interests, coupled with the diminishing prospects for constructing new water diversion projects, is forcing farmers in the western United States to cope with reduced surface water deliveries. The cost of improving instream water quality by reducing agricultural diversions is shown to depend mainly on how the supply reductions are allocated among users and on the extent of water trading. A central contribution of this paper is a methodology for measuring the impacts of water supply policy reforms on irrigated agriculture. The paper nests three empirical models in a general conceptual framework. The models differ in terms of their degree of detail and assumptions about input substitution. By comparing model results, it is possible to place bounds on the consequences of policy changes, and to identify critical factors determining economic impacts. The models are applied to the problem of improving water quality in the San Francisco Bay/Delta estuary.
A MODEL FOR THE WORLD: 80 YEARS OF MODEL DEVELOPMENT AND APPLICATION AT THE INTERNATIONAL PACIFIC HALIBUT COMMISSION
Authors: CLARK WILLIAM G.
Published: August 2010

ABSTRACT.This is a short history of modeling work done by the staff of the International Pacific Halibut Commission, from the pioneering work of Thompson and Bell through the present.
ENVIRONMENTAL UNCERTAINTY AND THE TIMING OF ENVIRONMENTAL POLICY
Authors: SAPHORES JEAN‐DANIEL M.
Published: August 2010

ABSTRACT. This paper shows that the timing of an investment to reduce the emissions of a stock pollutant under environmental uncertainty depends on the specification of uncertainty, on its level, and on the presence of a lower reflecting barrier for the stock pollutant. With quadratic damages, when variability increases with the level of pollution, emissions should be curbed immediately when uncertainty is large enough; when uncertainty is small, however, its impact is ambiguous. A lower reflecting barrier may also significantly influence the investment threshold. These results highlight the importance of better understanding the links between greenhouse gas concentration and weather variability.
ON SELECTIVE HARVESTING OF TWO COMPETING FISH SPECIES IN THE PRESENCE OF ENVIRONMENTAL FLUCTUATION
Authors: KAR TAPAN KUMAR , CHAUDHURI K.S.
Published: August 2010

ABSTRACT. The present paper deals with a problem of selective harvesting of two competing fish species in a randomly fluctuating environment. The environmental parameters are assumed to be perturbed by white noise characterized by a Gaussian distribution with mean zero and unit spectral density. The dynamic behavior of the stochastic system is studied and the fluctuations in population are measured both analytically and numerically by computer simulation.
MODELING CATASTROPHIC RISK IN ECONOMIC ANALYSIS OF FOREST CARBON SEQUESTRATION
Authors: STAINBACK G. ANDREW , LAVALAPATI JANAKI R.R.A.
Published: August 2010

ABSTRACT.The effect of risk from catastrophic tree mortality, such as fire, insect outbreaks and hurricanes, on selling credits for carbon sequestration from a slash pine plantation is modeled. We achieve this task by developing a modified Hartman model and applying it to a slash pine plantation. It is found that risk decreases the land expectation value and the optimal rotation age on a forest stand producing timber and carbon sequestration benefits. This decrease is greater with higher prices of carbon. Furthermore, risk increases the amount of pulpwood produced from the stand and decreases the amount of sawtimber produced. Since pulpwood has a shorter life span than sawtimber this reduces the amount of carbon sequestered. This effect is greater for higher prices of carbon suggesting that risk dampens the effect that a carbon market would have in inducing landowners to sequester more carbon.
OPEN ACCESS AND EXTINCTION OF THE PASSENGER PIGEON IN NORTH AMERICA
Authors: CONRAD JON M.
Published: August 2010

ABSTRACT. An open access model is formulated where X is a renewable resource and E is the level of effort devoted to harvest. Net growth is assumed to exhibit critical depensation and the open access system is described by two nonlinear differential equations

where r > 0 is the intrinsic growth rate, K1 is the minimum viable population level, K2 is the environmental carrying capacity, K2 > K1 > 0, q > 0 is the catchability coefficient, ? > 0 is an adjustment coefficient, (p – s) > 0 is the market price net of shipping cost, and c > 0 is the unit cost of effort at the harvest site. It is shown that the E= 0 isocline is a vertical line at X∞=c/[(p‐ s)q] and that the open access system passes through a supercritical Hopf bifurcation as X∞ moves from a level above (K1+K2)/2 to a level below (K1+K2)/2. For X∞ above (K1+K2)/2 the open access equilibrium is locally stable. For X∞ below (K1+K2)/2 the open access equilibrium will be locally unstable. At X∞=(K1+K2)/2 the system has a stable limit cycle. This analysis is useful in interpreting the economic history of the passenger pigeon. The limited empirical evidence would suggest that X∞=c/[(p – s)q] declined below (K1+K2)/2 during the last half of the 19th century as a result of improved rail transport and communications (the telegraph). It is thought that the passenger pigeon was extinct in the wild by 1901. The last passenger pigeon died in captivity at the Cincinnati Zoological Gardens on September 1, 1914.

X=rX(X/ K1– 1)(1 –X/K2)–qXE and

E=α[(p – s)qXE – cE],