bluuebunny/crossref_metadata_2025 huggingface dataset:
Tectonic Framework and Evolution of the Dabie Mountains in Anhui, Eastern China
Authors: Shutong Xu , Laili Jiang , Yican Liu , Yong Zhang
Published: August 2010

Abstract The Dabie Mountains are believed to be a collisional orogenic belt between the Yangtze amd Sino‐Korean continental plates. It is composed of the foreland fold‐thrust zone, the subducting cover and basement of the Yangtze continental plate, the coesite‐ and diamond‐bearing ultra‐high pressure métamorphic zone and the meta‐ophiolitic mèlange zone in the subducting basement, the fore‐arc flysch nappe and the back thrust zone occurring respectively on the southern and northern margins of the Sino‐Korean continental plate and the inherited basin with molassic deposits on the northern margin. When the palaeo‐Dabie oceanic plate subducted northward in the Early Palaeozoic, volcanic arc and back arc basin probably formed on the southern margin of the Sino‐Korean continental plate. The Sm / Nd isotopic dating of the strata and eclogite which were drawn into the foreland fold‐thrust zone indicates that the intense collision of the two continental plates took place in the Early Mesozoic.
Discovery of Fossil Charophytes from the Late Triassic Xujiahe Formation and Early Jurassic Lower Yimen Formation, Sichuan Province, and Its Significance
Authors: Junying Liu , Zhongliang Chen
Published: August 2010

Abstract This paper describes the fossil charophytes collected from the Late Triassic Xujiahe Formation in Dazu and Early Jurassic Lower Yimen Formation in Xichang, Sichuan Province, and their significance. Up to now, papers dealing with fossil charophytes of the Late Triassic, especially of the Early Jurassic, have been rarely published. The description of the two new species of Porochara, P. dazuensis and P. xichangensis, and their fossil assemblage not only provides an important basis for classification and correlation of red beds in southwestern China but reveals for the first time the features of the charophyte flora of the Late Triassic‐Early Jurassic in the area, thus offering valuable data for the establishment of Triassic and Jurassic charophyte fossil zones in China.
Multi‐level Detachments and Petroleum Potential of the Tarim Basin
Authors: Liangjie Tang
Published: August 2010

Abstract Four detachment systems have been found in the Tarim Basin. They are made up of the Proterozoic, Palaeozoic, Mesozoic‐Eogene and Neogene‐Quaternary, respectively. The shallow‐level detachments are characterized by the occurrence of fold‐thrust belts in the Meso‐Cenozoic. The mid‐level detachments are marked by nappes, decollement folds and drag anticlines in the Palaeozoic. The deep‐level detachments are represented by ductile shear belts in the basement. Mid‐ and deep‐level detachments mainly occur in the Northern, Central and Southern Uplifts which are major hydrocarbon accumulation belts of large‐scale oil fields. Shallow‐level detachments mainly exist in the Kuqa, Southwestern and Southeastern Depressions, which are favourable belts for finding medium‐ and small‐sized oil‐gas fields.
Geological Features of Triassic Alkaline and Subalkaline Igneous Complexes in the Yan‐Liao Area
Authors: Baolei Mou , Guohan Yan
Published: August 2010

Abstract A number of Triassic (245–195 Ma) alkaline or subalkaline igneous complexes were discovered in the Yan‐liao area in the northern part of the North China platform. These complexes are all poor in SiO2; most of them are rich in Fe, Mg, K and P and such incompatible elements as Rb, Ba, U and Sr and REE; the initial 87Sr/ 86Sr ratios range from 0.7055 to 0.7057. They might have originated in the altered upper mantle. On that basis coupled with the distribution of the Triassic System and the tectonic deformation, it is suggested that there should have existed a tectono‐magmatic belt in the area in Triassic time, which is an important manifestation of the Indosinian movement in the area.
Remote Sensing Study of Gold Biogeochemical Effects in the Western Guangdong‐Hainan Region1—A Case Study of the Hetai Gold Deposit
Authors: Ruisong Xu
Published: August 2010

Abstract The vegetation has been poisoned by gold in the western Guangdong‐Hainan region. The gold content of the leaves there is as high as 10‐1961 times the abundance, the chlorophyll content is 10%‐30% lower than that of the vegetation in metamorphic terrains and 10%‐20% higher than that in granite terrains, and the carotenoid content is 10%‐44% lower than the background value. The water content of leaves is 10% to 20% lower than the background value. The cells of leaves are deformed and broken. The leaf surface shows colour spots and becomes yellow or dark green. The spectral reflectance of the leaf surface is 5%‐30% higher than the background value; the spectral shape has shifted 5‐15 nm to the short wavelength. The gray scales of eanopy on images of Landsat TM and airborne imaging scanner (AIS) are 10%‐100% higher than the background values. On Landsat TM and AIS false colour images, plants poisoned by gold display a yellow color, which disinguishes them from background plants. According to the spectral and image features of gold biogeochemical effects, the author has constructed a gold information system and expert prediction system, and thus two gold target areas and two gold prospect areas have been identified rapidly, economically and accurately in the western Guangdong‐Hainan region which is extensively covered by vegetation.
Characteristics of the Mesozoic and Cenozoic Tectonic Stress Fields of the Urumqi‐Usu Region, Xinjiang
Authors: Mingxin Tao
Published: August 2010

Abstract Based on the study of folds and related conjugate shear joints, the tectonic stress fields of the Urumqi‐ Usu region to the north of the North Tianshan Mountains have been reconstructed. Furthermore the author discussed the tectonic movements and their dynamic features. The early tectonic movement in the investigated region occurred from the end of the Late Jurassic to the initial stage of the Early Cretaceous, with the maximum (tensile) and minimum (compressional) principal stress trajectories in the tectonic stress field being in E‐ W and S‐ N directions respectively; the late tectogenesis took place from the end of the Early Pleistocene to the initial Middle Pleistocene, with the maximum and minimum principal stress trajectories in the late stress field striking in WNW and NE‐NNE directions respectively. Through computer‐aided simulated calculation by the finite element method and analysis of geological structure, it has been ascertained that the early tectogenesis is a nearly N‐S compressive movement and the late one a NE to nearly N‐ S compressive movement with reverse shear. The dynamic force which caused the tectogeneses came from the movement of the southern major fault, i.e. the North Tianshan Mountains.
Electron Microscopic Study of Manganese Minerals in the Polymetallic Nodules from the Central Pacific Ocean
Authors: Xuqi Xiao , Shiqin Guo
Published: August 2010

Abstract Manganese minerals in the polymetallic nodules from the Central Pacific Ocean were studied using electron microscopy. The principal Mn minerals, being vernadite and todorokite, exhibit different electron diffraction patterns and morphological features. According to its morphological feature, todorokite shows three phases: fibrous, lamellar and lath‐shaped. Both vernadite and todorokite are authigenic minerals. While vernadite was mainly precipitated directly from the relevant solution by microbiological oxidation, todorokite was separated from the solution chemically without the help of microbe. Hence, these two minerals show a close genetic relation.
Sedimentary Characteristics of the Cretaceous in the Songliao Basin
Authors: Zhaojun Liu , Dongpo Wang , Li Liu , Wanzhu Liu , Pujun Wang , Xiaodi Du , Guang Yang
Published: August 2010

Abstract The rupture of the lithosphere in Late Jurassic brought about the eruption of basaltic magma in the Songliao Basin. The evolution of the basin in Cretaceous progressed through six stages: pre‐rift doming, extensional fracturing, fault subsidence, fault downwarping, downwarping and shringkage, resulting in the deposition of terrstrial facies nearly 10,000 m thick. There are different depositional sequences in these stages: the depositional period of the Early Cretaceous Shahezi and Yincheng Formations is the development stage of the down‐faulted basin, forming a volcanic rock‐alluvial fan‐fan delta‐lacustrine (intercalated with episodic turbidites)‐swamp facies sequences; the period of the Early Cretaceous Dengluku Formation is the transformation stage of fault subsidence into fault downwarping of the basin, forming a sequence mainly of alluvial plain‐lacustrine facies; the depositional period of the Early Cretaceous Quantou Formation‐Late Cretaceous Nenjiang Formation is the downwarping stage of the basin, forming an alluvial plain‐delta‐lacustrine facies sequence; the period of the Late Cretaceous Sifangtai Formation‐Mingshui Formation is the shringkage stage of the basin, forming again a sequence mainly of alluvial plain‐alluvial fan and small relict lacustrine facies. These vertical depositional sequences fully display the sedimentary characteristics of a failed continental rift basin. Many facts indicate that the two large‐scale lake invasions, synchronous with the global rise of sea level, which took place in the downwarping stage of the basin development, led to the connection between the lake and sea.
Mineral Composition and Metamorphic P—T Conditions of the Eclogitic Rocks in the Eastern Dabie Mountains and Their Genetic Implication1
Authors: Ningjie Ge , Shuguang Li , Zhonghua Peng , Deliang Liu
Published: August 2010

Abstract There are obvious differences in the mineral assemblage and metamorphic P—T conditions between the eclogites from the northern and southern parts of the eastern Dabie Mountains. Those from the northern part of the mountains are developed in Alpine peridotite and gneiss. They have a mineral assemblage of garnet+diopside with no quartz, and were formed at temperatures of 600 ° −740 °C. Those from the southern part are developed in gneiss and marble. They consist of garnet+omphacite+less quartz and were metamorphosed at temperatures in the range of 650 ° −8000 °C. These differences suggest that the former may be formed during the metamorphism of the deep subducted oceanic crust, whereas the latter may be genetically related to the subduction of the continental crust in this area.
Study of Water Flow in a Single Clay Crack
Authors: Zhonghua Ge , Bingheng Fan , Qiyan Feng , Yonghong Wang
Published: August 2010

Abstract A model has been constructed to study water flow in a single clay crack, and a new concept of the critical rise rate of water level in the crack has been put forward. When the water level rises faster than this critical rate, the flow in a crack will increase, and vice versa. The flow in a crack is not in proportion to the water level. The maximium water flow in clay is 30–40 times smaller than that in a rock fissure under the same condition. In the process of water discharge, the flow in a crack will lessen gradually, and the crack will grow narrower by 3.0–4.0 cm, with its depth reducing by over 50%.
Spectrum Characteristics and Transfer Function of the Hydrograph of the Deep Aqueous System1
Authors: Baoren Chen , Shuyun Liu , Peikang Jin , Shouyu Dong
Published: August 2010

Abstract The fluctuation of most of the hydrograph in the deep aqueous system records the fluid pulsation in lithosphere and variation of the earth's crust. Many observations have verified that groundwater is an ideal information carrier of the crust. In this paper, the series of input (precipitation, air pressure, Earth tide etc.) and output (water level, artesian flow) of the deep aqueous system are studied by using the spectrum analysis and system theory. The application concepts of transfer function and the spectral structure of the hydrograph enrich the knowledge of the deep aqueous system. Two typical spectral structures of the hydrograph of the deep aqueous system are obtained by comparing with many water—bearing systems of the Jizhong depression. One is from well Ma—17 and the other is from the well Xinze—5. Finally, the physical models of forming the spectrum of the hydrograph are constructed on the basis of the spectrum research on the deep aqueous system.
Geological Features of Devonian Sedimentary Basins in South China and Their Deposition and Mineralization
Authors: Wenjun Liu , Jinquan Zhang , Hongde Chen
Published: August 2010

Abstract The Devonian succession in South China is well‐known for its complete development, varified sedimentary types, remarkable lithofacies variation and abundant mineral resources. The South China plate was formed by the collision and collage of the Yangtze plate and the Cathaysian plate. The collision began approximately at the Jinningian stage and the collage was not finalized until the Guangxian movement. It was on the South China plate with a somewhat different nature of the basement that the Devonian deposition formed.
The Evolution of the Quaternary Salt Lakes in the Qaidam Basin
Authors: Xinjun Wei , Jixue Jiang
Published: August 2010

Abstract The paper discusses the distribution of Quaternary sediments, occurrence of saline minerals and phases of neotectonic movements and their manifestations in the Qaidam basin. The formation of four successive lacustrine terraces in Tertiary anticlinal zones in the western part of the basin was related to the neotectonic movements that took place 100 Ka ago, and the distribution of such terraces discloses, in a way, the evolutionary history of the Quaternary salt lakes. According to the distribution of the terraces coupled with the distribution of Quaternary sediments and features of salt deposition, four periods of Quaternary salt lake evolution in the basin may be distinguished, which correspond to four stages of salt deposition respectively.
Experimental Study on the Mechanism for the Formation of Sn‐bearing Granite in Northern Guangxi1
Authors: Xiangji Liang , Li Qiao , Fusheng Wang , Chonghui Yang
Published: August 2010

Abstract Experimental results have proved that the Xuefengian Sn‐bearing biotite granites were formed by remelting and recrystallization of the Proterozoic metamorphic rocks of the Sibao Group at 500 × 105 —2000× 105 Pa and 750‐570 °C and further testified that the F‐ and B‐bearing aqueous solution played an important part in decreasing the formation temperature of the rocks. The results tally with the reality of the field geology. The authors have thus brought to light the mechanism for the formation of the Sn‐bearing biotite granites and expounded the significance of their formation in the crust dynamics of South China.
The Zoulang Nanshan Caledonian Subduction Complex in the Northern Qilian Mountains and Its Dynamics1
Authors: Zhiqin Xu , Huifen Xu , Jianxin Zhang , Haibing Li , Zhizhi Zhu , Jingchuan Qu , Daizhang Chen , Jinlu Chen , Kaichun Yang
Published: August 2010

Abstract The front of the Zoulang Nanshan Caledonian volcanic island arc zone in the northern Qilian Mountains is a forearc accretionary terrane, composed of multiple accretionary volcanic island arcs, flysch accretionary wedges, high ‐ pressure metamorphosed detachment zones and remnants of ophiolites. It resulted from the northeastward subduction of the Early Palaeozoic Qilan oceanic crust beneath the Alxa block. High ‐ pressure metamorphism, which occurred during the subduction, progressed through three stages: the initial stage of medium T ‐ high P, the main stage of temperature decrease and pressure increase, and the lag stage of pressure decrease and temperature increase. Finally the paper presents a retrotrench subduction dynamic model indicative of northward subduction of the central Qilian block and southward accretion of the Alxa block during the period of 450‐500 M a.
Isotope Hydrogeological Study of Karst Water in the Lu' an Mining District and the Xin' ancun Spring Basin, Shanxi
Authors: Zizhen Gong , Zhaolin Li , Zhigan Zhang , Liqun Fu , Baolin Zuo
Published: August 2010

Abstract Isotope hydrogeological study has shown that the water supply exploration area in the Lu' an coal mine may be divided into four zones of hydrodynamic conditions and the Xin' ancun Spring Basin where the mine is located may be divided into three Middle Ordovician karst water systems. This paper discusses the features of recharge, runoff and discharge of karst water in various zones, and hydrogeological parameters such as the age, flow rate and natural recharge of karst water have been estimated.
Age Assignment of the Lycoptera ‐ bearing Bed
Authors: Peixian Li , Deying Su , Yougui Li , Jingxian Yu
Published: August 2010

Abstract In the Yanliao area, the occurrence of the Nestoria ‐ Keratestheria fauna and the Eoparacypris‐ Luanpingella ‐ Darwinula assemblage in the Dabeigou Formation s.s., a Rb‐Sr isochron age of 145.2 Ma for the Baiqi Formation and a complete stratigraphie sequence—all this proves that the Lycoptera‐ bearing bed overlies the Upper Jurassic. The Jehol fauna comprises the primitive Trigonioidids fauna, Eosestheria fauna, Lycoptera fauna et al., and their own laws of evolution expound that they belong to Cretaceous faunas. The associations of Eosestheria with Yanjiestheria, Lycoptera with Eosestheria, and Kuntulunia with Yanjiestheria as well as the occurrence of early angiosperms and sporo ‐ pollen in the Fuxin Formation and its equivalents also demonstrate that the Lycoptera‐ bearing bed should be assigned to the Cretaceous. The confirmation of the existence of Aucellina in the Jixi Group and the correlation of Trigonioidids and Cypridids with those in the equivalent strata of Japan and Western Europe have also been verified by corresponding marine strata. According to the magnetostratigraphic data from Zhejiang and Songliao, it has been preliminarily ascertained that M0 between the mixed polarity zone in the lower part and the normal polarity zone in the middle part of the Cretaceous is located in the upper member of the Huangjian Formation of the Jiande Group and the top member of the Denglouku Formation of the same group, and the isotopic age data of the Jehol and Jiande Groups show that the approximate geologic age of the Lycoptera bed is 135‐122 M a. These prove that the Lycoptera bed should be assigned to the Cretaceous.
The Ultrastructure and Origin of Upper Sinian Cherts on the Southeast Continental Margin of the Yangtze Platform1
Authors: Haisheng Yi , Yunfu Zeng , Wenjie Xia
Published: August 2010

Abstract Through microscopic and SEM observations and X‐ray diffraction and energy spectrum analyses, the oldest sponge spicules and radiolarians have been found in bedded cherts and it is proposed that microbial activity of algae and bacteria played an important role in silica precipitation. The microbial activity resulted in the formation of a series of single crystals and crystal aggregates with peculiar shapes. Biogenic single crystals usually occur in spherical, rod, platy, colloidal and granular forms. The most common aggregates are framboidal aggregates composed of dense spherical quartz crystals, which are considered to be of typical bacterial origin. Other aggregates, such as favositic, double‐spherical, chain ‐spherical and coccoid ones, are considered to be probably the result of silicification of algal cells and mainly of primary sedimentary origin. This paper also discusses the ultrastructural features and diagnostic indications of jasper rocks formed in a submarine hydrothermal environment and cherts formed by replacement and diagenetic recrystallisation.
On the Origin of Migmatites in Yunlu, Western Guangdong
Authors: Bin Chen , Fusheng Huang
Published: August 2010

Abstract Partially migmatized rocks, banded migmatites, augen‐banded migmatites and gneissic migmatites are developed successively from Xindong to Yunlu, Gaozhou, Guangdong Province in the Yunkai Caledonian orogenic belt at the border between Guangdong and Guangxi. Mass‐balance calculations, statistical analysis of the textural relations and mineralogical and geochemical studies of the migmatites and the study of the metamorphic setting of the Yunlu area indicate that the migmatites in the study area were primarily formed by anatexis without remarkable introduction of foreign components such as K, Na and Si and removal of Ca, Fe, Mg, etc.
The Age and Character of the Yu'erhong Flora from Yumen, Gansu
Authors: Guanglong Shen , Xiuyuan Wu , Jun Wang , Huaqin Liu
Published: August 2010

Abstract: From a fresh field investigation, it has been ascertained that the Late Palaeozoic Yu'erhong (Yüerhhung) flora from Yu'erhong, Yumen, Gansu, northwestern China, studied by Bohlin in 1971 includes plants from the Westphalian Yangfukou Formation and the Stephanian to Sakmarian Taiyuan Formation. The Yu'erhong flora from the Yanghukou Formation is dominated by Euramerican elements with a few elements of the Cathaysian flora. No Angarian elements have be found in this section for lack of Late Permian strata. The specimens studied by Bohlin might possibly come from the upper part of the Upper Permian at tne southeastern corner of the Yu'erhong basin. Those fossils from different horizons and localities might be mixed with each other during collection; so they fail to reflect the exact horizon of certain plant fossils.
Chemical Indicator of Spinel During Partial Melting and Subsolidus Equilibration of Mantle Peridotite: Experimental Study and Application to Natural Rocks
Authors: Jianping Li , Kornprobst Jacques , Vielzeuf Daniel
Published: August 2010

Abstract Systematic experimental studies on partial melting and subsolidus equilibration of three reconstituted spinel ‐ peridotites have been carried out at temperatures ranging from 1000 to 1380°C. and pressures of 1.0 and 1.5 GPa: The results show: (1) during partial melting, Mg# [=Mg/(Mg+Fe)]and Cr# [=Cr/ (Cr+Al)] of spinel increase with an increase in degrees of melting; (2) during subsolidus equilibration, with increasing temperatures, Mg# of spinel increases but Cr# of spinel remains almost unchanged in dunite and increases slightly in lherzolite and harzburgite. The negative and quasi ‐ linear Mg# ‐ Cr# correlation of spinel represents an isotherm of total non ‐ equilibrium. The same results have been obtained by means of mathematical modelling. It is also proved by Mg# ‐ Cr# correlation of spinel in natural peridotites. As a result of the spinel subsolidus equilibration, only variation of Cr# of spinel is limited, and then Cr# of spinel can be used to estimate the relative degree of melting undergone by host rocks. The bigger Cr# of spinel is, the higher the degree of melting will be. By contrast, during crystallization magma, Mg# and Cr# of spinel decrease with decreasing temperatures. Likewise, Cr# of spinel in basalts may be used to indicate the feature of Cr2O3/Al2O3 of magma, and the compositional zoning of spinel may be used to study the evolution of magma (cooling rate and contamination).
Chengdeite—A New Mineral of Ordered Natural Iron‐ iridium Alloy
Authors: Zuxiang Yu
Published: August 2010

Abstract Chengdeite occurs in chromite orebodies in dimite as well as in placers in their neighbourhood. The mineral occurs as granular aggregates in association with inaglyite and in some cases occurs as graphic intergrowths with native iridium. It is opaque with a metallic lustre, colour steel‐black, streak black, HM= 5.2, VHN50=452 kg/mm2, cleavage not observed, fracture not observed, strongly magnetic. Its reflection colour is bright white with a yellowish tint. It has no internal reflection, bireflectance or pleochrism, and shows isotropism.

Thirteen chemical analyses were carried out by means of the electron microprobe. The mean percentages of the data obtained in the 13 analyses are: s 0.001, Fe 7.9, Ni 0.03, Co 0.03, Cu 0.83, As 0.02, Rh 0.19, Pd 0.00, Os 0.06, Ir 88.5, Pt 2.2 and Pb 0.00. The simplified formula is Ir3Fe, which requires Ir 91.17 and Fe 8.83, the total being 100.00 (%).

Five strongest lines of X‐ray powder diffraction (hkl, d, I) are: 111, 2.18 (80);200, 1.89 (60); 220, 1.34 (70); 311, 1.142 (100); 222, 1.094 (80).

Through indexing of the X‐ray powder diffraction data, the mineral has been determined to be cubic with Pm 3m, a=0.3792 (5)nm, V=0.05453nm and Z=1.
Petrology, Metamorphic Process and Genesis of The Dabie—Sulu Eclogite Belt, Eastern—Central China
Authors: Zeming Zhang , Zhendong You , Yujing Han , Longkang Sang
Published: August 2010

Abstract The Qinling—Dabie—Sulu high—pressure and ultra—high pressure metamorphic belt was formed by subduction and collision between the North China and Yangtze plates. The study of the eclogite belt is very important in understanding the evolution of the Qinling Dabie orogen. In the present paper the geology, petrology, minerology and chronology of the eclogites in the Dabie and Sulu areas are described. The principal conclusions of this work are as follows: (1) Based upon the field occurrence and the P—T conditions of the eclogites, two types of eclogite can be distinguished: Type 1—the low‐temperature and high—pressure eclogite in the mid‐late Proterozoic metamorphic series, and Type 2—the ultra‐high pressure eclogite in the late Archaean to early Proterozoic metamorphic complex. In the Dabie area, the ultra‐high‐pressure eclogite, high—pressure eclogite and epidote‐blueschist units are nearly parallel to each other and stretch intermittently from north to south. (2) The P—T conditions of the high—pressure eclogites and ultra‐high pressure eclogites have been estimated. The former are formed at 450—550°C and 1.4‐1.6 GPa; while the latter at 650—870°C and >2.7—2.9 GPa in the Dabie area and at 820—1000°C and > 2.8—3.1 GPa in the Sulu area. The metamorphic temperatures of the eclogites increase progressively from west to east. (3) The ultra—high pressure eclogites were subjected to 5 stages of metamorphism: pre‐eclogite epidote amphibolite facies, peak coesite eclogite facies, post—eclogite amphibolite facies, epidote—blueschist facies or epidote amphibolite facies and greenschist facies. The general features of the PTt path of the ultra‐high pressure eclogite are: clockwise pattern, progressive metamorphism being a process of slow increasing temperature and rapid increasing pressure, and the retrogressive section with nearly isothermal decompression at the early stage, isobaric cooling at the middle stage and nearly isothermal decompression at the late stage. (4) At least two stages of high‐pressure metamorphism occurred in the orogenic belt: the high‐pressure eclogite and ultra‐high pressure eclogite were formed by the subduction of the oceanic crust northward beneath the North China plate or the Dabie block during the Caledonian; while the epidote‐blueschist belt came into being by subdution and collision between the two continental plates during the Indosinian. (5) Due to the continuous sequential subduction of the cold plate, the ultra high—presssure metamorphic rocks were uplifted to the crust by the underplating processes. They can be preserved just because of the “frozen effect” resulting from the continuous subduction of the cold plate. (6) The carbonates, such as magnesite, breunnerite, aragonite and dolomite, and the H2O—bearing minerals, such as phengite, epidote and zoisite, were stable during the high‐pressure and / or ultra—high pressure metamorphism.
Experimental Study of the Influence of Hydrous Minerals on the Melting Behaviour of Rocks at High Temperatures and Pressures
Authors: Haifei Zheng , Hongsen Xie , Yousheng Xu , Maoshuang Song , Yueming Zhang , Mingzai Wang , Huigang Xu
Published: August 2010

Abstract The experimental study on the melting of potassic basalt and eclogite with about 2% water at 800—1300°C and 1.0—3.5 GPa shows that the solidi of both rocks are significantly lower than those obtained from the previous experiments of the same type of rocks under dry conditions, and the former which is enriched in potassium has a lower melting point than the latter. It is consistent with the previous study. The melting temperature of eclogite increases with pressure, whereas potassic basalt has similar properties only at 1.5—2.5 GPa and >3.0 GPa, and at 2.5— 3.0 GPa the melting temperature decreases with pressure. This can be explained as follows: (1) eclogite only has one hydrous mineral amphibole and the dehydous temperature is lower than the wet solidus of the rock. (2) Amphibole exists in potassic basalt at the pressures lower than 2.5 GPa and phlogopite exists at pressures higher than 2.5 GPa, and the special compositions of both minerals determine that amphibole has a dehydration temperature higher than or close to that of the wet solidus of the rocks, while phlogopite has a dehydration temperature lower than that of the wet solidus. On the other hand the features of the continuous solidus in the experiment of hydrous eclogite were produced by the fact that the dehydration temperature of its amphibole lower than or close to the melting temperature of the hydrous conditions. So the melting temperature lowers at higher pressures. Therefore, the composition of the rocks in the lithosphère and the types of hydrous minerals and their stable P‐T conditions are the important factors controlling the solidi of rocks. It can quite well explain the partial melting of rocks and the origin of the low velocity zone in the deep lithosphere.
The Early Evolution of the Acanthomorphic Acritarchs in China and Their Biostratigraphical Implication
Authors: Chongyu Yin , Linzhi Gao
Published: August 2010

Abstract On the basis of a study of the acanthomorphic acritarchs discovered in the Late Proterozoic to Early Cambrian Meishucunian Stage in different regions of China, especially in southern Shaanxi and the Yangtze Platform, coupled with a study of the assemblages, morphological correlation, microstructure, and evolutional relations of the acanthorphic acritarchs, as well as a wide correlation with those found in different regions of the world, the authors discuss the early evolutionary stages of the acanthomorphs, features of their assemblages in various stages, their biostratigraphical significance, and their evolutionary trend in China.
Extension Model of Crustal Uplifting in Western Shandong
Authors: Shouxun Yan , Guiliang Wang , Zhenjie Shao , Xiangang Meng
Published: August 2010

Abstract Block faults, as the dominant tectonic framwork of western Shandong, were formed by the linked extensional fault system through two extensional movements during the Meso‐Cenozoic. Both of the extensional movements experienced the same evloutional process: first, the upper crust was pulled apart to form faults; then the Tai‐Lu‐Yi (Taishan‐Lushan‐Yishan) fault block occurring in the footwall of the extensional fault was uplifted, which induced the shallow‐level detachment movement along the early Precambrian and Palaeozoic unconformity; the “branching” fault in the upper part of the deep‐level detachment layer propagated. As the shallow detachment moved towards the north and the deep one towards the south, the Tai‐Lu‐Yi fault block acted as the common footwall of both the southern and northern detachment systems. The Tai‐Lu‐Yi fault block rebounded and uplifted as the overlying material was pulled apart to cause an unloading. Sialic material of the mid‐crust below the deep detachment flowed to and accumulated in the free space below the rebounding uplifted body and thickened the body; whereas the mid‐crust thinned under the graben systems. The rebounding uplifted body cooled, and then the graben system was occluded, which resulted in the crust‐mantle isostatic adjustment and asthenospheric convection. As a result of the two extensional movements, the uplifted central Shandong block with the Tai‐Lu‐Yi area as the core stands highly above the surrounding plain characterized by graben systems. The present Mount Taishan forms the climax of the uplift.
A Study of Sedimentary Environment and Reservoir Quality of the Carboniferous Donghe Sandstone in the Tarim Basin
Authors: Jiayu Gu
Published: August 2010

Abstract Very thick, fine–grained quartzose sandstone of the Lower Carboniferous (called the Donghe sandstone) was discovered in Donghe–1 well in the Tarim basin. Highly–productive commercial oil and gas flows were obtained when a well completion test was conducted. This important discovery proved that the quartzose sandstone is a prospecting target with good prospects. After that, other two paying oil and gas flows were found in the Lower Carboniferous in the Tazhong–4 and Tazhong–10 structures (Tazhong means central Tarim), equivalent to the Donghe sandstone. The Tazhong–4 structural oil field is the biggest oil field ever discovered. Therefore it is of guiding importance in oil and gas exploration to deepen the study of sedimentary and reservoir features and the sedimentary environment of the Donghe sandstone and to build a sedimentary model in order to understand the reservoir distribution pattern.
Subsolidus Phase Relations in the System MgO–SiO2–Cr–O and Thermodynamic Properties of Related Cr2+–Containing End–members
Authors: Jianping Li , Neill H, St, C O' , Seifert F.
Published: August 2010

Abstract Subsolidus phase relations have been determined in the systems SiO2–Cr–O and MgO–SiO2–Cr–O in equilibrium with metallic Cr, at 1100 to 1500°C and 0 to 2.88 GPa. The results show that there are no ternary phases in the SiO2–Cr–O system at these conditions, i.e., only the assemblage eskolaite–Cr–metal–quartz (or tridymite) is found. In the MgO–containing system, however, extensive substitution of Cr2+ for Mg is observed in (Mg, Cr2+)2SiO4 olivine, (Mg, Cr2+)2Si2O6 pyroxene, and (Mg, Cr2+)Cr2O4 spinel. Cr3+ levels in olivine and pyroxene are below detection limits. The pyroxene is orthohombic at XPxCr2+ <0.2, monoclinic at higher XPxCr2+. The structure of the spinels becomes tetragonally distorted at XPxCr2+ >0.2. The experimental data have been fitted to a thermodynamic model, and the authors obtained the mixing parameter (W) of Mg‐Cr2+ in olivine, pyroxene and spinel, and the relation between temperatures and free energies of formation for the end–members: Cr2+–olivine (Cr2SiO4), Cr2+–pyroxene (Cr2Si2O6) and Cr2+–spinel (Cr3O4).
Long‐term patient outcome 10 years after video‐assisted thoracoscopic surgery lobectomy for non‐small‐cell lung cancer
Authors: Imakiire T , Iwasaki A , Hamatake D , Shiraishi T , Shirakusa T
Published: August 2010

Introduction: Although there have been many reports associating video‐assisted thoracoscopic surgery (VATS) with improved survival rates in early lung cancer, almost all of the reports have involved short median follow‐ups and been presented at a 5‐year point. Here, we establish the pattern and frequency of recurrences, as well as the long‐term survival rates of patients who have undergone VATS more than 10 years ago.

Methods: We retrospectively studied 41 patients who underwent VATS lobectomy for clinical stage I non‐small‐cell lung cancer at Fukuoka University Hospital between November 1994 and December 1999. All patients underwent lobectomy, including a dissection of hilar and mediastinal lymph nodes. Follow‐up consisted of clinical and radiological examinations every 3 months for the first 2 years after the surgery and then once a year thereafter.

Results: Of the 41 patients, 31 were diagnosed to be at pathologic stage IA and six at stage IB, while the remaining four were more advanced cases. During the follow‐up period, recurrences were found in five cases (12.2%). Four patients with recurrence died of lung cancer and an additional two died from cancers of other organs. There were other non‐cancer related deaths, largely from respiratory failures. Overall, the 5‐ and 10‐year survival rates after the operation were 79.8% and 68.8%, respectively.

Conclusion: Long‐term survival and recurrence rates after a classic VATS lobectomy for lung cancer are favorable compared to the conventional approach.
SOURCES, SINKS AND SELECTIVITY
Authors: CARROLL JOSEPH E. , LAMBERSON ROLAND H.
Published: August 2010

ABSTRACT. A model, which consists of a system of several nonlinear ordinary differential equations, is developed to describe a metapopulation. Results regarding the location and stability of fixed population vectors are obtained, including conditions for the existence of multiple stable equilibria. The convergence of all solutions is established.
SPATIAL DYNAMICS OF TWO HARVESTED WILD PIG POPULATIONS
Authors: KEELING M.J. , MILNER‐GULLAND E.J. , CLAYTON L.M.
Published: August 2010

ABSTRACT. Simple one‐ and two‐dimensional spatial models are developed for the harvesting of wild pigs in North Sulawesi, Indonesia. The models are used to explore the effects of changes in biological and economic parameter values on the spatial persistence of harvested populations, when off‐take must be transported to market. A two‐species model shows that the relative catchability of species harvested together strongly affects the distance from market at which each species persists. Due to strong positive feedback, travel costs are a major determinant of the length of the regions where pigs are extinct and exploited.
WILDLIFE LOSSES IN KENYA: AN ANALYSIS OF CONSERVATION POLICY
Authors: NORTON‐GRIFFITHS M.
Published: August 2010

ABSTRACT. Despite massive conservation efforts backed bysignificant international support, Kenya has lost some 44% of its large mammal fauna over the last 17 years. This catastrophic example of resource degradation stems from a mixture of policy, institutional and market failures.

Policy failures include an over‐reliance on Command and Control (prohibition on consumptive use of wildlife, prohibition on use of resources within Protected Areas) without the ability to enforce compliance; subsidies to agricultural and livestock production which, by reducing marginal production costs to below social opportunitycosts, has caused the over‐conversion of rangelands to livestock and agricultural production at the expense of conservation objectives and values; and the establishment of tourism cartels which divert wildlife generated benefits awayfrom landowners. The fundamental institutional failure is the lack of property rights and use rights of landowners over wildlife. Fundamental market failures reflect the absence of financial incentives to landowners to conserve their wildlife resource, thus setting marginal depletion costs to zero, and competing production incentives.

The Kenya Wildlife Service (KWS) is reintroducing financial incentives to landowners by permitting some consumptive use of wildlife, bymaking substantial direct grants to landowners and communities who support wildlife and bysidelining the tourism cartels and encouraging private sector tourism on private land. However, investment in conservation is still being hampered by the continuing prohibition of high value activities such as sport hunting, and by over regulation and vacillation.

Furthermore, positive net benefits to landowners from wildlife operations are not in themselves adequate to guarantee economic incentives to conserve the resource. First, significant negative externalities are associated with wildlife in that they add greatly to the production costs of livestock and agriculture; second, opportunity costs (in terms of foregone benefits of development) of leaving land undeveloped for conservation are gradually increasing in response to growing populations, expanding markets and new agricultural technology; and third, some policies are having the perverse impacts of creating poverty traps.

Wildlife conservation policy must accordingly be much wider in scope and use a much broader range of economic, financial and market instruments, possibly including differential land use taxes, conservation subsidies and easements, and lease back agreements. Simply creating positive net benefits from wildlife is not enough.
PEST OUTBREAKS CONTROL: THE APPROACH OF PEAK‐TO‐PEAK DYNAMICS
Authors: CIRITA SERGIO RINALDI , PICCARDI CARLO , GRAGNANI ALESSANDRA
Published: August 2010

ABSTRACT. Insect pest outbreaks in natural and exploited forests are often recursive but aperiodic. We show, by means of a continuous‐time model, that the randomness of these devastating episodes is a very special kind of deterministic chaos, known as peak‐to‐peak dynamics, since the intensity of any outbreak can be predicted from that of the previous episode. This fact allows one to solve various control problems such as the minimization of the mean damage associated with the pest outbreaks or the regularization of their time pattern.
MIXED‐STOCK VS. TERMINAL FISHERIES: A BIOECONOMIC MODEL
Authors: ROUTLEDGE RICK
Published: August 2010

ABSTRACT. This paper develops a bioeconomic model of a fishery conducted on several stocks, a large stock capable of supporting a commercial fishery, and one or more smaller stocks which could be driven to extinction at harvest rates that the larger stock can sustain. The model permits a shifting of effort from a mixed‐stock fishery to single‐stock fisheries. Such a shift could save the weaker stocks from extinction, but the model highlights economic incentives to reject this option. This points to a fundamental conflict between the preservation of biodiversity and economic pressures to maximize profits. This fundamental conflict has in turn important consequences in current debates over the restructuring of major fisheries including those directed at Pacific salmon.
AB INITIO MODELING OF ECOSYSTEMS WITH ARTIFICIAL LIFE
Authors: ADAMI C.
Published: August 2010

ABSTRACT. Artificial Life provides the opportunity to study the emergence and evolution of simple ecosystems in real time. We give an overview of the advantages and limitations of such an approach, as well as its relation to individual‐based modeling techniques. The Digital Life system Avida is introduced and prospects for experiments with ab initio evolution (evolution “from scratch”), maintenance, as well as stability of ecosystems are discussed.
THE ECONOMICS OF MARINE RESERVES
Authors: HANNESSON RÖGNVALDUR
Published: August 2010

ABSTRACT. Marine reserves can be a useful supplement to other methods of fisheries management, but marine reserves alone are not likely to achieve a great deal in economic terms andperhaps not even in terms of conservation. The effects of marine reserves with open access elsewhere are analyzed, using a logistic model for a population with a patchy distribution. It is assumedthat a marine reserve is establishedfor the territory of one of two sub‐populations which interact through migrations. The total population increases while the total catch declines for the most part. A high rate of migration would, however, dilute the conservation effect.

Examining a stochastic variant of the model shows that the variability (sum of squareddeviations) of catches may decrease as a result of protecting one of the sub‐populations. Even if all rents disappear by assumption, it is possible to identify this as an economic benefit, particularly when the average catch increases. The variability of the catch falls for a range of values of the population migration parameter and variability of growth, both when the stochastic disturbances are independent and when they are perfectly correlated for the two sub‐populations, andalso when the growth variability parameter differs between the sub‐populations.
A COALITION APPROACH TO THE MANAGEMENT OF HIGH SEAS FISHERIES IN THE PRESENCE OF EXTERNALITIES
Authors: PINTASSILGO PEDRO
Published: August 2010

ABSTRACT. The current paper extends the coalition approach of the management of high seas fisheries to the presence of externalities. The coalition approach is set within the framework of a two‐stage game in which the payoffs depend on the entire coalition structure and are determined through a partition function.

The relationship between the presence of externalities and the stability of the coalition structures is explored. The equilibrium coalition structures of the game are also examined.

The application of the game to the Northern Atlantic bluefin tuna shows a typical picture of the high seas fisheries: the simultaneous presence of strong externalities in the coalition structures and the absence of stability of the grand coalition.

A fundamental conclusion of this paper is that, generally, in order to guarantee the stability of the cooperative agreements it is not sufficient to implement a fair sharing rule for the distribution of the returns from cooperation. Stability requires a legal regime preventing the players that engage in noncooperative behavior from having access to the resource.
RESTRICTED COALITIONS IN THE MANAGEMENT OF REGIONAL FISHERIES ORGANIZATIONS
Authors: LINDROOS MARKO
Published: August 2010

ABSTRACT. In this paper, we examine a game theoretic setting in which four countries have established a regional organization for the conservation and management of straddling and highly migratory fish stocks as recommended by the United Nations Agreement. These countries consist of two coastal states and two distant water fishing nations (DWFNs). A characteristic function game approach is applied to describe the sharing of the surplus benefits from cooperation. We are specifically interested in the effect of possible coalition restrictions on these shares. According to our results the distant water fishing nations, by individually refusing to join with the coastal states, can considerably improve their negotiation position if their harvesting costs are relatively high and similar. The results show that the DWFNs may have economic reasons for negotiating as a group against coastal states. However, if the coastal states are clearly more efficient than the DWFNs then coalition restrictions may be prevented by coastal states.
MANAGING HARVESTING TO MINIMIZE THE IMPACT OF EPIDEMICS ON WILD FISH STOCKS
Authors: MURRAY ALEXANDER G.
Published: August 2010

ABSTRACT. Epidemic diseases inflict substantial damage to stocks of harvested species. Epidemic waves can be predictable away from their origin. I use a classical epidemiology model to investigate the interaction of harvesting strategy with an epidemic. The effect of reducing populations by harvesting before the epidemic depends upon the nature of the epidemic's survivors. If these have recovered following infection, then pre‐epidemic fishing optimizes the harvest, but reduces long‐term survival. However, if these survivors avoided infection, then increased pre‐epidemic fishing effort can increase post‐epidemic populations; survival is maximized by reducing the pre‐epidemic population to the threshold required to propagate infection. Post‐epidemic harvesting provides poor returns and damages stocks. Optimal stock management strategy in the face of a predicted epidemic depends upon balancing harvesting and conservation of stocks complimentary or antagonistic goals, depending on the nature of the epidemic.
SURVIVAL OF THE FITTEST IN A QUASILINEAR SIZE‐STRUCTURED POPULATION MODEL
Authors: ACKLEH AZMY S. , DENG KENG
Published: August 2010

ABSTRACT. We present a size‐structured model which describes the dynamics of n ecotypes competing for common resources. We prove that if reproduction is closed, i.e., offspring of one ecotype belongs to the same ecotype, then competitive exclusion between these ecotypes will occur. We give conditions on the model parameters which determine the fittest ecotype that wins the competition. Furthermore, we show that if reproduction is open then coexistence between the n ecotypes is possible.