bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessment of Tree Rings as a Hydrologic Record in a Humid Subtropical Environment1
Authors: Crockett Kris , Martin Jonathan B. , Grissino‐Mayer Henri D. , Larson Evan R. , Mirti Thomas
Published: August 2010

Crockett, Kris, Jonathan B. Martin, Henri D. Grissino‐Mayer, Evan R. Larson, and Thomas Mirti, 2010. Assessment of Tree Rings as a Hydrologic Record in a Humid Subtropical Environment. Journal of the American Water Resources Association (JAWRA) 1‐13. DOI: 10.1111/j.1752‐1688.2010.00464.x

Abstract:  Information about long‐term variability of streamflow is important to allocate water resources, but few historical records extend more than 75 years into the past, requiring proxy records to evaluate flow prior to that time. Flow proxies have been found in tree‐ring widths in temperate regions, but have rarely been used in humid subtropical environments because the relationship between tree growth and climate was believed to be weakened by limited seasonality and stress on tree growth from drought conditions. Tree‐ring residual chronologies from two forests sampled from northern Florida correlate well with historical annual discharge (r² values as high as 0.47) from 3 of 15 river‐gauging stations that were used to compare with the tree‐ring chronologies. The best correlations occur where streamflow has little contribution from spring discharge or continuous flow from lakes and wetlands. Streams lack correlations with the tree‐ring residual chronologies (r² values as low as 0.0002) where springs and continuous discharge from lakes mute variations in their flow. Tree‐ring chronologies appear to be useful for reconstruction of prehistorical variations of some streamflow in humid subtropical regions, but interpretations of the reconstructions must consider the local hydrologic conditions.
Design of Experimental Streams for Simulating Headwater Stream Restoration1
Authors: Huang Jung‐Chen , Mitsch William J. , Ward Andrew D.
Published: August 2010

Huang, Jung‐Chen, William J. Mitsch, and Andrew D. Ward, 2010. Design of Experimental Streams for Simulating Headwater Stream Restoration. Journal of the American Water Resources Association (JAWRA) 1‐15. DOI: 10.1111/j.1752‐1688.2010.00467.x

Abstract:  Headwater streams flowing through agricultural fields in the midwestern United States have been extensively modified to accommodate subsurface drainage systems, resulting in deepened, straightened, and widened streams. To restore these headwater streams, partial or total reconstruction of channels is frequently attempted. There are different approaches to reconstructing the channel, yet there is little evidence that indicates which promises more success and there has been no experimental work to evaluate these approaches. This study designs three experimental channels – two‐stage, self‐design, and straightened channels – on a human‐created swale at the Olentangy River Wetland Research Park, Columbus, Ohio, for long‐term evaluation of headwater stream evolution after restoration. The swale receives a continuous flow of pumped river water from upstream wetlands. Using streamflow and stage data for the past 12 years, a channel‐forming discharge of 0.18 m3/s was estimated from bankfull discharge, effective discharge, and recurrence interval. These stream channels, after construction, will be monitored to evaluate physical, chemical, and biological responses to different channels over a decade‐long experiment. We hypothesize that the three stream restoration designs will eventually evolve to a similar channel form but with different time periods for convergence. Monitoring the frequency and magnitude of changes over at least 10 years is needed to document the most stable restored channel form.
Mass Extinction——A Fundamental Indicator for Major Natural Divisions of Geological History
Authors: Daoyi Xu , Qinwen Zhang , Yiyin Sun
Published: August 2010

Abstract In the Phanerozoic, there are three major geological boundaries: Precambrian / Cambrian, Permian / Triassic and Cretaceous / Tertiary. Studies of these boundaries in China and over the world strongly suggest that they have the following similar features: mass extinctions of many, taxa, positive anomalies of platinum‐group metals, and abrupt changes of stable isotopes (δ13C). It is quite probable that these were the consequences of some rare catastrophic events of extraterrestrial origin. Hence, the three above‐mentioned mass extinction events may be regarded as key indicators for the division of the geological history of the Phanerozoic.
Tectonomechanical Analysis of Listric Faults
Authors: Qiang Chen
Published: August 2010

Abstract Listric faults of different levels and scales are widely developed in the lithosphere. According to their tectonomechanical geneses, the author divides listric faults into primary and secondary ones, and the former may be subdivided into gravity‐ gliding listric faults, regional extensional listric normal faults, regional contractional reverse listric faults and deep‐ seated ductile listric faults. By means of the slip‐ line field theory dealing with Mohr's criterion expressed by quadratic limiting curves, the author has preliminarily determined the occurrences, patterns and mechanical properties of various types of listric faults during their formation, and has analyzed their tectonic evolution and related dynamic processes in the lithosphere.
Mathematical‐Physical Modelling of Seismic Response of the Beijing Depression
Authors: Yimin Peng , Jinzhong Sun , Xiansheng Hao
Published: August 2010

Abstract There is a NE‐ trending earthquake hazard anomalous zone in the western part of the area of the city of Beijing proper. A comprehensive study of it has been made. In the study the two‐dimensional finite element dynamic analysis and supersonic seismic model experiments were conducted for the first time, and some preliminary results have been achieved.

The Beijing depression, a lower order tectonic unit in the Beijing downwarp, is just located below the earthquake hazard anomalous zone. Analysis of the experimental results shows that the topography of the buried bedrock is the main factor responsible for the presence of the anomalous zone. Besides, the two‐dimensional mathematical analysis has more marked advantages in reflecting the lateral inhomogeneity of the foundation as compared with the one‐dimensional one, and the supersonic seismic model experiments may reflect the integrated effects of the earthquake sources, path of wave propagation and site geological structure in an all‐round way.
The Origin of the Echelon Structures of Tungsten Veins in Xihuashan, Jiangxi 1
Authors: Shaoxun He , Xiaoshuang Xi
Published: August 2010

Abstract Analysis of the variations in the three‐dimensional structural forms of the tungsten veins in the Xihuashan tungsten district has proved that echelon structures of the veins were formed by the changes in stress direction that caused the breakdown of the individual single veins, and are different from the echelon faults formed in shear zones. Echelon structures of the veins were produced near the lithologic boundary as a result of the rotation of stress direction in their neighbourhood and their control of vein distribution. The change in the echelon pattern caused by the variation in the attitude of lithologic boundary surface in the district is an interesting structural phenomenon. The echelon structures also reflect the variation characteristics of adjacent veins in the process of their propagation.
On Metallogenic Conditions and Regularities of the Lower and Middle Reaches of the Changjiang River
Authors: Xiangpei Liu , Yinfo Chang , Yenchang Wu
Published: August 2010

Abstract The paper deals with the metallogenic conditions and regularities of the region of the lower‐middle reaches of the Changjiang River in China. The complicated structural network with the Changjiang (Yangtse) deep fracture as its trunk is the leading rock‐ and ore‐ controlling structure of the metallogenic belt. The high‐potassium granodiorites of the first magmatic sequence of the Mesozoic Yangtse syntexis type and the sodium‐rich diorites of the second sequence are genetically related to the copper ore series and the iron ore series respectively, and occur respectively in the block‐faulted and ‐folded uplift area and the down‐faulted volcanic basin as well as the transitional zone between the two. The ore‐hosting horizons show specific associations of rocks and often contain ore beds basically of stratabound nature.
Types, Metallogenic Environments and Characteristics of Temporal and Spatial Distribution of Copper Deposits in China
Authors: Zhitian Wang , Kezhang Qin
Published: August 2010

Abstract Based upon a comprehensive study of 123 copper deposits in China, this paper reaches the following conclusions: 1. The crust in China was solidified pretty late; with the accretion of the plate, the copper mineralization moved towards its margin in space and became successively younger in age. 2. The major copper ore types ever found in the world have mostly been discovered in China, in which the porphyry type seems to be the most important and the massive sulfide type in the transitional bed between marine clastic and carbonate rocks is clearly defined. 3. Carbonate strata are widespread in China and their deposition lasted for a long geological period, so the proportion of copper deposits occurring in them is large as compared with other parts of the world. 4. Seven metallogenic epochs can be recognized, in which the Mesozoic one plays the leading role and the middle (late) Palaeozoic and Cenozoic ones are next in importance. Mineralization was comparatively simple in the early geological period, and became diversified later on. In the early epochs copper deposits related to basaltic magmatism and metamorphosed marine sediments predominated, whereas in the later epochs those. related to granitic magmatism and continental sedimentation were dominant. 5. There exist in China thirteen metallogenic provinces, of which the Lower Yangtze downwarping belt, Sanjiang fold system, Jiangnan axis and Xikang‐ Yunnan axis are of greater significance. 6. The crustal mobility in China was rather pronounced, the polycyclic evolution of the crust has resulted in such obvious phenomena as the inheritance of mineralization, the coexistence of various types and the superposition of different genetic types.
The Nadanhada Terrane
Authors: Shinjiro Mizutani , Ji' an Shao , Qinglong Zhang
Published: August 2010

Abstract The Nadanhada terrane, a Jurassic disrupted terrane in Heilongjiang Province of China, is principally composed of Permo‐ Carboniferous limestone and greenstone, Triassic bedded chert and middle Jurassic siliceous shale, all enclosed within younger (presumably Late Jurassic‐ Early Cretaceous) clastics. Palaeontological and lithological characteristics and structural features of these formations are entirely identical to those of the Mino terrane of the Japanese Islands. Prior to opening of the Sea of Japan, these terranes formed a single superterrane together with the Western Sikhote‐Alin terrane. Tectono‐stratigraphic terranes very similar to the Nadanhada and Mino terranes are also found in the Ryukyu are, the Philippines and probably in Borneo. All these terranes constituted a belt of accretionary complexes during Late Jurassic and / or Early Cretaceous time along the eastern continental margin of Asia after completion of the Triassic collage of the Chinese continent.
Sr, Nd and O Isotopic Studies on the Genesis of the Huashan Granite Complex1
Authors: Jinchu Zhu , Xiangdong Li , Weizhou Shen , Yinxi Wang , Jiedong Yang
Published: August 2010

Abstract Systematical Sr, Nd and O isotopic studies were made on the Huashan granite complex in Guangxi. In combination with the studies of geological, petrological and geochemical data, it is believed that the complex consists of granites of three stages, with different geneses and different source materials. They are not the products of differentiation and evolution of one single consanguineous magma. Granites of the 1st stage are of the Indosinian syntectic type or I type, also derived from a mixed mantle‐crustal source. Those of the 2nd stage are of the early Yanshanian syntectic type or I type, also derived from a mixed mantle‐crustal source, and those of the 3rd stage are of the late Yanshanian transformed type or S type, derived from a crustal source.
The Late Proterozoic Trench‐Basin‐Arc System in the Northeastern Jiangxi Southern Anhui Region
Authors: Bei Xu
Published: August 2010

Abstract Proterozoic rocks in the northeastern Jiangxi‐southern Anhui may fall into three rock associations which belong to different but interrelated tectono‐palaeogeographic units. The field geological and petrochemical characteristics of the northeastern Jiangxi‐western Zhejiang volcanic zone indicate that it was once an island arc zone. An analysis of the sedimentary characteristics of Proterozoic turbidites lying north of the zone has revealed the history of development of a back‐arc basin. According to the type of the Proterozoic rock formation south of the zone, it may be deduced that the formation might represent the fore‐ arc and French areas. By means of various tectono‐palaeogeographic analyses, the relation between the island arc zone and the back‐arc basin is inferred and the Late Proterozoic tectono‐ palaeogeographic development is discussed by using the model of the trench‐arc‐basin system.
Geophysical and Geological Features of the Meso‐Cenozoic Lower Yangtze Rift Zone
Authors: Shengzao Chen
Published: August 2010

Abstract It is clarified in this paper that the Lower Yangtze depression is a Meso‐Cenozoic rift zone formed on the basement of the Hercynian‐Indosinian foreland basins. The rift zone is divided into eastern and western sectors and is different in northern and southern parts. The rift zone in plane combination comprises parallel, trifurcate or splitting rifts. The North Jiangsu‐South Yellow Sea region represents a.“drift‐type” rift basin whose deposition center migrates gradually eastward. The formation mechanism and dynamic evolution of the rift basin are discussed from a viewpoint of the crustal fine‐structure, with evidence in geology and geophysics and analysis results of dynamic forces given.
The Characteristics of the Indosinian Pacific‐Type Ancient Continental Margin in the Qinghai‐Xizang (Tibet)‐Sichuan‐Yunnan Region1
Authors: Yanlin Gao
Published: August 2010

Abstract The Qinghai‐ Xizang (Tibet) Plateau and the “Sanjiang” area2, where are extensively developed the Tethys‐type marine Triassic sequences with Indosinian tectonic disturbance and magmatism, provide an important region for the study of the tectonic evolution and the Indosinian movement of China as well as for the study of the boundary between Gondwana and Laurasia and the characteristics of the time‐space distribution of the Tethys oceanic crust within the territory of China. Over a long period of time in the past, quite a number of scholars made substantial studies and discussions from various viewpoints on the geotectonic and regional geological evolution of this region. Based on some new data obtained recently and the field observations by the author, and by using the plate tectonic theory, the author considers that there developed a Pacific‐type (active type) ancient continental margin bordering the Palaeo‐Tethys ocean (or North Tethys ocean) in the south in Late Permian to Triassic times in the region of south‐central Qinghai, northeastern Xizang (Tibet), western and southwestern Sichuan, and western Yunnan. Its characteristics basically represent the Indosinian tectonic evolution of this region.
Mesozoic Volcanic‐Intrusive Complexes in the Coastal Area of Southeastern Zhejiang Province: Their Features, Petrogenesis and Distribution Pattern
Authors: Yangsong Du , Dezi Wang , Kerong Chen
Published: August 2010

Abstract On the basis of previous studies and by means of field geological, remote sensing, petrographical, mineralogical, petrochemical and geochemical investigations, the authors studied the temporal‐spatial distribution of the regional structures, volcanic structures and products of volcanic activity in the coastal area of southeastern Zhejiang. On the basis and through a systematic comparison of the products of magmatism in the area, it is considered that there exists a compsite volcanic structural belt composed of linear and circular structures and it has been demonstrated that there exist volcanic intrusive complexes‐“trinity” composed of volcanic, subvolcanic and plutonic rocks. It is suggested that the volcanic intrusive complexes in the area belong to, the typical syntexis series and that its materials were derived from a mixed source of crust and mantle.
Sequence Stratigraphy and Tectonic Enyironment of the Chartai Group, Inner Mongolia
Authors: Xiufu Qiao , Peiyi Yao , Chengshu Wang , Lin Tan , Shenyu Zhu , Shengde Zhou , Yuqing Zhang
Published: August 2010

Abstract The Middle Proterozoic Chartai Group separated by two unconformities consists of three depositional sequences: the Shujigou Formation‐Zenglongchang Formation (DS I ), the Agulugou Formation (DS II ), and the Liuhongwan Formation (DSIU). The carbonate platform and back‐platform basin are the basic environment model of the Chartai Group. The syndepositional faults on the oceanward side of the carbonate platform and large‐ scale slumping in the soft sediments are important marks of facies tracts. The newly established Zenglongchan uplifting, an epeirogenetic uplifting, plays an important role in the formation of the palaeogeographic framework of the Chartai Group. The stratigraphic correlation between the Chartai Group and the Bayan Obo Group is made for the first time by using sequence stratigraphic principie and model established by P.R. Vail. The Chartai Group, which was deposited on the northern passive continental margin of the North China platfom, represents the platform cover.
The Late Palaeozoic Rifting on Hainan Island, China1
Authors: Bangdong Xia , Guangyu Shi , Zhong Fang , Jinhai Yu , Ciyin Wang , Xiancong Tao , Huimin Li
Published: August 2010

Abstract There occurred rifting on Hainan Island in the Late Palaeozoic. Bimodal volcanic rocks composed of basalt and rhyolite developed in the Carboniferous. Widespread in the Late Palaeozoic formations are several layers of fluvial intermontane conglomerates whose distribution is controlled by rift faults. The Late Palaeozoic deposits dominated by clastic rocks are, for a major part, of marine facies and of continental facies in the lower and upper parts. Lithological and lithochemical studies indicate that the detrital rocks were formed in a tectonic setting of continental rifting. The evolution of the rifting terminated at the stage of transition form an intra continental rift to an intercontinental one and the rift basin was a bay opening westward to the sea.
Analysis of Some Characteristics of the Fault Activities in Eastern China by Satellite Images
Authors: Guanglin Xie
Published: August 2010

Abstract Active faults have special electromagnetic effect and remote sensing characteristics, and exhibit unique imagery marks in satellite images. A comprehensive comparison of images of active faults in eastern China and an analysis of geologic and geomorphic data can tell us some characteristics of fault activity in the area during the neotectonic period: 1) The fault activities of the north‐south tectonic zone, North China and Taiwan were stronger than those of southeastern and northeastern China; 2) the faulting in the north‐ south tectonic zone, North China and Taiwan has continued up to now, and most of the fault activites in southeastern and north‐eastern China have become weaker since the Middle Pleistocene; 3) the activity is unsteady in time, most being intermittent, or episodic, i.e. alternately strong and weak; 4) most active faults of a definite size can be divided into several segments which somewhat differ from each other in the characteristics of the activity.
A Simulated Test of Algal Influence of Formation and Deposition of Phosphates
Authors: Zhili Liu , Xuexian Liu , Yigong Fan , Shixin Zhu
Published: August 2010

Abstract This paper deals with a simulated test of biogenic mineralization made with a blue‐ green alga species, Spirulina platensis. The data in the experiment were recorded by a computerized surveying system. The influence of algae on the accumulation of phosphorus by changing their microenvironment to promote the formation and deposition of phosphate was studied.

The results show that the pH value of cultural liquor rose up to 10 and the redox potential (Eh) may drop by 100‐200 mV during the algal logarithmic growth stage, and the cultrual liquor was changed into a medium with a weakly reducing condition. At the end of the logarithmic growth stage white deposits of Na2Ca(CO3)2 · 5H2O and Ca2Mg (PO4)2 · 2H2O were formed on the floor of cultural containers. The test presented a valuable evidence for the theory of biogenic mineralization.
The Geoscience Transect from Xiangshui, Jiangsu Province to Mandal, Inner Mongolia*
Authors: Xingyuan Ma , Changyuan Liu , Guodong Liu
Published: August 2010

Abstract The Xiangshui to Mandal geoscience transect, which has a total length of 1,200 km, extends diagonally, from SE to NW, across the Sino‐Korean plate and its ancient continental margin, passing through nine tectonic units: the Subei‐Jiaonan terrane, West Shandong block, North China rift basin, Taihang‐Wutai block, Ordos block, Hu‐Bao (Hohhot‐Baotou) Basin, Yinshan block and Inner Mongolian fold system.

The graphic display of the transect is compiled according to the Guidelines for the Global Geoscience Transect (GGT) Project on the basis of an integrated study of all available geological, geochemical and geophysical data, thus bringing light to the process of cratonization of the Sino‐Korean plate and its relationship with the transitional zone of the ancient continental margin, and the features of intraplate structures produced by subsequent tectonic modifications and intraplate dynamics.
The Characteristics and Mechanism of Island‐Arc Volcanism on the Central and Southern Fildes Peninsula, King George Island, Antarctica
Authors: Zhaonai Li , Xiaohan Liu , Ruxiang Shang
Published: August 2010

Abstract The volcanic rock series on the Fildes Peninsula is the product of the later subduction of the Pacific plate beneath the Antarctic plate. It consists mainly of basalt, basaltic andesite and andesite with minor dacite. Its isotopic ages range from 64.6 ± 1 to 43 ± 2 Ma, belonging to Palaeocene to Eocene. Volcanism in the area may be divided into two phases. The contents of major oxides, rare earth elements (REE) and trace elements in volcanic rocks formed in different phases show regular changes, which are mainly related to the rock associations of these phases. Isotope geochemical studies indicate that the primitive magma in the area originating by partial melting in the upper mantle underwent fractional crystallization and ascended to the high‐level (shallow) magma chamber. Before eruption the primitive basalt‐andesitic magma was subjected to differentiation in the high‐level magma chamber, forming zones of derivative magmas of different compositions. In various phases magma‐conducting faults experienced periodic extension and cut through various derivative magma zones in different parts of the peninsula, leading to the eruption of magmas of different compositions on the surface and the formation of volcanic rock associations of corresponding compositions.
Palaeogene Biostratigraphic Characteristics of Red Basins In Western Henan and Its Adjacent Areas, With an Outline of Palaeogene Palaeobiogeographic Provinces of China
Authors: Hengjian Du , Ancheng Ma , Jie Cheng , Weimin Wu
Published: August 2010

Abstract This article is a preliminary summary of Paleogene biostratigraphy of the Liguanqiao, Tantou and Yuanqu basins, with a new proposal for Paleogene paleobiogeographic provinces of China. On the basis of a synthetic analysis of the geological data, characters of the mammalian assemblages and their comparisons with other corresponding faunas, a new scheme on Paleogene biostratigraphic subdivision of the basins has been put forward here. Based on differences of biostratigraphic sequences, characteristics of mammalian assemblages and directions of faults controlling Paleogene basins in China, six Paleogene paleobiogeographic provinces of China have been proposed in this paper, that is: Tianshan‐Yinshan‐Tumen Province; Tarim‐North China Province; Kunlun‐Qinling Province; Yangtze Province; Nanling and Southeastern Coastal Province; Qinghai and Tibet Province.
Geochemistry and Genesis of the Sodium Charnockitic Gneisses, Eastern Hebei Province, China
Authors: Anjian Wang
Published: August 2010

Abstract High in sodium and low in potassium (Na2O/K2O > 1), the charnockitic gneiss series in the Santunying‐ Taipingzhai area, eastern Hebei province, consists of hypersthene‐ quartz‐ diorite, hypersthene‐granodiorite and hypersthene‐plagioclase‐granite. Geological, petrological and large ion lithophile element (LILE), high field strength element (HFSE) and REE geochemical studies suggest that the medium‐coarse‐grained hypersthene‐granodiorite is the product of crystallization of anatectic magmas of the same composition. Under granulite facies conditions, the equilibrium crystallization differentiation of the magmas yielded the early crystallization phase—high‐ SiO2, LILE‐depleted, low‐ΣREE, positive Eu anomaly and REE‐ saturated hypersthene‐ plagioclase‐ granite. The residual phase, coarse‐ grained to pegmatitic hypersthene‐granodiorite, is marked by low SiO2, LILE‐enrichment, high ΣREE and REE‐undersaturation. These rocks and hypersthene‐quartz‐diorite enclaves constitute the sodium‐charnockitic gneiss series in eastern Hebei province. Model calculation for trace elements in the granitoids was applied. On the basis of a systematic geological study, the equation for calculation was chosen, the source magma was determined and the partition coefficients were obtained. The resulting curves are entirely consistent with those observed in the patterns of actual rocks. The study indicates that whole‐rock REE patterns can not be used directly in the comparison of the sources and genesis of granitoids.
The Late Proterozoic Continental Accretionary History of the Southeastern Margin of Jiangnania
Authors: Fengming Xing , Xiang Xu , Jiangfeng Chen , Taixi Zhou , Foland K.A.
Published: August 2010

Abstract The newly obtained Sm‐Nd isochron ages are 1034 Ma and 935 Ma for ophiolites from northeastern Jiangxi and Fuchuan, southern Anhui respectively. There exist two unconformity surfaces under the initial Late Proterozoic volcanics as well as the Sinian rocks. The Xiuning intrusive body which was intruded into the Shangxi Group in southern Anhui yields a whole‐rock Rb‐Sr isochron age of 963 Ma. There occurs a belt of Late Proterozoic calc‐alkali volcanic rocks extending from northeastern Jiangxi to northwestern Zhejiang. In the light of the above facts, the authors consider that the southeastern margin of Jiangnania is an ancient island arc. At about 1000 Ma ago, the Huanan (South China) oceanic crust was subducted along the line linking Dexing and Hangzhou, thus starting the accretion of the island arc system to Jiangnania. At 800 Ma ago Cathaysia and Jiangnania converged together along the Jiangshan‐Shaoxing line, marking the end of the accretion.
Hydrogen and Oxygen Isotope Fractionation Mechanism in the Hydrothermal System and Its Geologic Significance
Authors: Zhensheng Chen , Ligang Zhang
Published: August 2010

Abstract The geochemical behaviors of hydrogen and oxygen isotopes in the hydrothermal system and their inherent relationship with the water / rock exchange are discussed in this paper. In addition to the temperature conditions, the effective W / R ratio is another factor controlling the changes in H and O isotope compositions of the altered rock and hydrothermal water. Besides, the application and geological significance of the water‐rock exchange theory are also discussed in the light of the H and O isotope compositions and their variation characteristics of the mineralizing hydrothermal water and altered rocks from several mineral deposits. Finally, a brief evolutional model of H and O istotope compositions of meteoric and magmatic hydrothermal waters in a hydrothermal system is given.
Microfossils from the Chert in the Lower Cambrian Shuijingtuo Formation at Miaohe, Zigui, Hubei Province1
Authors: Chongyu Yin , Zhao Yue , Linzhi Gao , Qixiu Ding
Published: August 2010

Abstract This paper reports for the first time on the microfossils discovered in the black cherts of the basal part of the Lower Cambrian Shuijingtuo Formation at Miaohe village, Zigui County, Hubei Province, all of which were observed in thin sections. Nine genera, 9 species and 3 indeterminate species (including a new species) are described. According to these microfossils, the conclusion is made that the microfossil zone may be equivalent to the small shelly fossil assemblage zones 2‐3 of the Meishucun stage. They have provided another important line of evidence for the correlation of the Sinian‐Cambrian boundary strata with those of the adjacent areas.
The Machanism of Bacterial Oxidation of Sulphides
Authors: Ende Wang , Guangyue Guan
Published: August 2010

Abstract The bacteria used in the experiment are Thiobacillus Ferrooxidans separated from acidic mine water in sulphide deposits. The chemoautotrophic bacteria can act directly on sulphides and accelerate the oxidation of sulphides. The experiment shows that the bacteria, as an important microbial factor of gold's supergenous enrichment within the oxidized zones of sulphide deposits, are helpful to dissolve gold and silver in ferric sulphate. In the bacterial oxidation process, the precipitation of goethite is concerned both with the lower activity of ferric ions and with the existence of carbonates in solution. Meanwhile, the acid‐resisting and oxidizing ability of the bacteria will certainly lead up to a microbial way of treating the acidic mine water.
Basal Melt‐out Structure in the Luoquan Formation and Its Significance1
Authors: Daokai Ge , Zhijiu Cui
Published: August 2010

Abstract The Late Precambrian Luoquan Formation occurring on the southern margin of the North China platform is of important significance for the study of the tectonics, palaeogeography, palaeoclimatology and regional stratigraphy of the North China and Yangtze platforms. The origin of diamictites of the formation has long been a subject of controversy. Recently a certain type of cross bedding structure has been recognized in the massive diamictite. Analysis of the process of deposition indicates that the structure was formed by the basal melt‐out process of the glacier and, to some extent, its form is the manifestation of the primary structure of basal debris‐rich glacial ice. The discovery of this sedimentary structure is inducive to the understanding and reconstruction of the features and environmental conditions for the development of the glaciers in the Luoquan Glacial Epoch.
The Sedimentary Sequence and Palaeogeographic Changes of the South Yellow Sea Since the Olauvai Subchron1
Authors: Zigeng Yang
Published: August 2010

Abstract According to the alternation of terrestrial beds and transgressive beds, the sedimentary sequence of the South Yellow Sea since the Olduvai subchron can be divided into 15 strdatigraphical intervals. According to the facies analysis, there are 7 transgressive beds an one bed with transgression marks, and classical transgressive‐regressive facies sequence also appears in the major transgressive beds.

Palaeogeographic evolution in the shelf area involved 4 periods: (1) 1.70‐0.5 Ma B. P. was the stage for the development of the Palaeo‐Yangtze River alluvial plain and delta. Tide influenced‐river channel sediments formed during the Olduvai have been found in borehole QC2. The river mouth was located near 124° E and during the transgressive stage from 0.97‐0.73 Ma B.P. to the east of 122.2° E, a large‐scale undersea delta was formed. In the regressive stage, the shelf area became an alluvial plain. (2) 0.50‐0.75 Ma B.P. was a multi‐transgressive fluctuation stage during which 3 transgressive beds (HVI, HV, HIV)developed, being dated as 0.50‐0.30 Ma B.P., 0.27‐0.20 Ma B.P. and 127‐75 Ka B.P. respectively, with the extent of transgression increasing gradually. Influenced by southeast monsoons, the eastern China continent began to have a larger moisture source. (3) 75–14 Ka B.P. was the lower sea‐level stage during the last glacial period. The downcuttihg depth of rivers was up to ‐133 m. The palaeo‐Yangtze River system flowed northeastwards into the Sea of Japan through the Sea of Japan through the Tsushima and Korean Straits. The interfluvial area became an eroded, weathered high land. In the cores, two short‐lived, relatively high sea‐level stages were recorded, corresponding to two interstades in the last glacial period. (4) The period since 14 Ka B.P. is the stage for “Holocene transgression” and the development of the Yellow River‐Huaihe River delta. Before 14 Ka the sea level rose to ‐68 m, and before 11 Ka to ‐50 m, and the sea‐level was once at a standstill or slightly got down, which is coincident with the Younger Dryas event. The Yellow River‐Huaihe River delta developed on transgressive bed HI and consists of the superimpositions of 6 deltaic complexes.
Seismic Sequence in Carbonate Rocks By Vibrational Liquefaction1
Authors: Xiufu Qiao , Tianrui Song , Linzhi Gao , Yang Peng , Haibing Li , Mai Gao , Biao Song , Qiaoda Zhang
Published: August 2010

Abstract On the basis of the records of strong seismic events taking place in soft carbonate sediments, a new seismic sequence system of vibrational liquefaction is established, which consists of a series of units, such as escaped structure of micrite veins and liquefied deformation formed in the period of seismic liquefaction, land subsidence structure after liquefaction, tsunamic hummocky and turbidite produced by seismic events, This sequence is a generalization and summation of field observation in vast areas, which shows the whole process of a strong seismic event and provides an unified theoretical explanation. The pattern of the seismic sequence by vibrational liquefaction provides one of correlation standards for geologists in the field to discriminate events in carbonate sequences. Based on the pattern of seismic sequence, the authors first advance a new conception of the Palaeo ‐ Tanlu (Tancheng ‐ Lujiang) Zone and discuss primarily its geological significations.
Isotope Geochemistry of the Xinchang – Yongjia Silver (Lead – Zinc) Ore Belt in Eastern Zhejiang Province
Authors: Butai Xu , Changjiang Li , Haoshou Chen
Published: August 2010

Abstract In the Xinchang‐Yongjia silver (lead‐zinc) ore belt, there mainly occur the large to medium‐sized Haoshi, Bamao, Dalingkou and Wubu silver deposits or silver‐bearing lead‐zinc deposits. On the basis of researches on these typical deposits, the mechanism of leaching‐drawing mineralization of Mesozoic geothermal water and the related model are put forward in this paper in the light of the time interval between rock and formation ages as well as hydrogen, oxygen, sulphur and lead isotope geochemical characteristics. The major metallogenic process occurred in volcanic rock layers. The ore‐forming fluids are geothermal water coming from meteoric water and circulating at shallow layers. This geothermal water leached and absorbed ore‐forming materials from its country rocks during its flowing (such metallogenic elements as silver, lead‐zinc and sulphur mainly came from consolidated volcanic rocks), leading to the formation of meso‐epithermal silver deposits.
Geology Along the Line from Yecheng to Shiquanhe and Tectonic Evolution of the Region Involved1
Authors: Yusheng Pan , Yi Wang , Matte Ph , Tapponnier P.
Published: August 2010

Abstract The geotraverse from Yecheng to Shiquanhe, on the western Qinghai – Tibet Plateau, totalling 1056 km in length, passes the western Kunlun Mountains and the eastern end of the Karakorum Mountains. The Chinese and French scientists made a joint investigation along the line from July to August, 1989. Based on the outcropped ophiolites, palaeontology, sedimentary facies, magmatism, tectonic deformation and metamorphism, the region involved may be divided from north to south into five terranes and four ophiolitic suture zones. The ages of these terranes have a tendency to become increasingly younger from north to south.
The Existence of the Negative Charge of Gold in Sulphide Minerals and Its Formation Mechanism1;
Authors: Jiuling Li , Daming Feng , Feng Qi , Guilan Zhang
Published: August 2010

Abstract: Through a study, particularly an X‐ray photoelectron spectroscopy (XPS or ESCA) analysis, of gold‐bearing arsenopyrite and pyrite in Carlin‐type gold deposits of Guangxi, China, and hydrothermally synthesized gold‐bearing pyrite and marcasite, the authors have found that these minerals contain “invisible gold” whose binding energy is lower than that of native gold (Au°). Therefore they suggest that gold occurs in a negative charge state in these sulphide minerals as it replaces some sulphur and is combined with sulphur with the covalent bond. This paper also preliminarily discusses the possibility of its formation from the chemistry and geochemistry of gold, crystal chemistry of arsenopyrite, pyrite and marcasite and geochemical environment.
The Origin of Bedded Cherts of the Early Permian Gufeng Formation in the Lower Yangtze Area, Eastern China
Authors: Bangdong Xia , Lirong Zhong , Zhong Fang , Hongbo Lu
Published: August 2010

Abstract Bedded cherts occurring in the Early Permian Gufeng Formation in the Lower Yangtze region, eastern China, are nearly 20‐80 m in thickness and contain varying amounts of radiolarians and sponge spicules. There are three types of section for the Gufeng Formation: chert, carbonate and chert ‐ carbonate mixing types. Bedded cherts mainly occur in the first and third types of section. The depocentres of silica are marked by some small (not larger than a few thousand square kilometres in area) rhombic or elliptic hollows and their formation was controlled by faults. Argillaceous volcanic rocks in cherts occur as numerous thin layers. Bedded cherts are characterized by higher Fe and lower Al contents, enrichment in such trace elements as As, Sb, Bi, Ga, Au, Ag and Cr, lower total REE abundance, negative Ce anomaly and varying degrees of HREE enrichment. These characteristics are important evidence for hydrothermal cherts. Minor amounts of substances of non ‐ hydrothermal origin are mixed in the cherts. The temperatures of sea water range approximately from a few tens of degrees to over 160°C. during the deposition of siliceous sediments.
Dynamics of O re‐Forming Processes of the Stratabound Skarn Copper Deposits of Tongling, Anhui Province
Authors: Chonggwen Yu , Yaosong Jiang , Zhengyu Xiao
Published: August 2010

Abstract The skarn and ore bodies of the stratabound skarn copper deposits of Tongling, Anhui Province, are both controlled by definite stratigraphic horizons, and they are concordant with the strata. They occur as layers and layer‐like bodies in permeable carbonate rocks of the Middle‐Upper Carboniferous Huanglong and Chuanshan Formations which are underlain by impermeable shale or siliceous rocks of the Upper Devonian Wutong Formation. The authors study the dynamics of ore‐forming processes of the ore deposits with the dynamic model of coupled transport and reaction, and the following results are obtained: The salinity gradient and flow rate of the ore‐forming fluids can both promote the mixing and reaction of juvenile water and formation water, and the permeable strata are favourable sites for the intense transport‐reaction of mixing and the formation of deposits. (2) As isothermal transport‐reaction took place along the bedding of strata, the moving transport‐reaction front formed at the contact between the ore‐forming fluids and the rocks advanced slowly along the permeable strata, and then stratiform skarn and ore bodies concordant with the strata were formed. (3) The gradient transport‐reaction taking place across the isotherms in the cross‐bedding direction caused the mineralogical composition to alter gradually from magnesian skarn to sulphide ore bodies.
Numerical Modelling of Geochemical Behaviour of Fluoride in the Shallow Groundwater Systems
Authors: Jianhui Zeng
Published: August 2010

Abstract The Xingtai piedmont plain in Hebei Province is a representative area in northern China where endemic fluorosis is serious and shallow high‐F groundwater is distributed. In this paper, the area is selected as a typical study area, and on the basis of large amounts of field work and the experiments, through groundwater geochemical modelling and by applying the theory and method of the coupled model of hydrodynamic transport and chemical reactions in a multicomponent system, the author performed numericalmodelling of the geochemical behaviour of fluoride in a shallow groundwater system, quantitatively studied the hydrodynamic transport and chemical reaction of fluorine migration, transformation and concentration in a water‐heterogeneous unsaturated soil system under the conditions of meteoric water infiltration and quantitatively determined the speciation of fluorine and the saturation state and dissolution/precipitation trend of various solid precipitates in shallow high‐F groundwater, thus deepening the understanding of the geochemical behavious of fluorine in shallow groundwater and revealing the essence of some environmental problems at a higher level.
Isotope Geochemical Characteristics and Material Sources of Tin‐Bearing Porphyries in South China
Authors: Weizhou Shen , Dezi Wang , Changshi Liu
Published: August 2010

Abstract Tin—bearing porphyries in South China can be divided into the F—rich and F—poor subtypes. They are high—silica (SiO2>71%), peraluminous (A/NKC>1.0) and rich in incompatible elements (Rb, Zr, U, W, Sn) and have weak Ce (δCe = 0.68‐0.82) and strong Eu (δEu = 0.01—0.38) negative anomalies. Meantime, they also have low εNd(‐6.3‐ ‐8.4), high 207Pb/ 204Pb (15.588‐15.790), medium to high (87Sr/ 86Sr)i (0.7084‐0.7287) and relatively high δl8O (9.1—lO.3%o). These characteristics clearly suggest that the two subtypes of tin‐bearing porphyries were derived from the crustal materials. Their differences lie only in the existence of certain different components in their source materials. Therefore, there is only one type of tin‐bearing prophyry in South China, that is continental crust transformation type.
Changshanian Maximum Flooding Event in China and Its Global Correlation
Authors: Xianghua Meng , Ming Ge , Tucker M.E.
Published: August 2010

Abstract Various orders of condensed sections are recognized in the Cambrian of North China Carbonate Platform. Study of comparative sedimentology proves that CS4–CS5 in the Changshanian age is the maximum sea flooding sediments in the Cambrian, regardless of the distribution, thickness, internal structure of the condensed section series and K2O abundance. It is a two‐layered composite condensed section series, characterized by the enrichment of such elements as K, P, Mn, Ti, Co, V, Cr, Cu, Zr, Ni, Li, Th, La, Ce, Nd, Dy, Y, Sc and Be. The Changshanian maximum flooding event can be correlated on a global scale, and the corresponding sedimentary records are discovered in 26 intercontinental sections in N. Europe, N. America, and Tarim and the Yangtze Platform of China. Through detailed sedimentological research, meter–scale cycle analysis and Fischer plots, it is concluded that the Changshanian maximum flooding was a composite effect of the second‐order eustacy superimposed by the third‐and fourth‐order eustacy, which lasted for 1.2‐3 Ma. An intercontinental model of the Changshanian maximum flooding is proposed at the end of this paper.
Interactions of Copper, Evaporite, and Organic Matter and Genesis of Sandstone–Hosted Copper Deposits in the Chuxiong Basin, Yunnan Province
Authors: Hanping Zhuang , Chongying Ran , Mingqin He , Jialan Lu
Published: August 2010

Abstract Studies on organic geochemistry indicate that the origin, type and maturity of organic matter are different among coal–bearing, copper–bearing and evaporite formations in the Mesozoic continental Chuxiong Basin, Yunnan, China. A mechanism has been proposed that (1) during the diagenetic mineralization stage the short–chain organic acids dervied from kerogen played an important role in remobilizing copper from source beds, while oils acted as important carrier of copper, and that (2) during the transformation or remolding mineralization stage, meteoric water leached the evaporite layers and formed downward–percolating oxidizing SO2‐4 –rich fluids; meanwhile, the copper–bearing fluids migrating upwards along growth faults from the basement was contaminated by the coal–bearing series on the way and formed reducing organic–rich fluids; oxidation–reduction occurred and sulfides formed when the two kinds of fluids met within sandstones.
Silurian–Devonian and Jurassic Thermal Events in the Or dos Basin, China: Indications from K–Ar Dating on Illites
Authors: Mengwei Zhao , Ahrendt Hans , Wemmer Klaus , Behr Hans–J rgen
Published: August 2010

Abstract In the Ordos basin, two distinct thermal events of different ages have been identified for the first time by means of K–Ar dating combined with illite crystallinity analysis. For the Late Triassic and Late Permian samples, the K–Ar ages of the < 0.2 µm fractions (159‐173 Ma) refleet an unitization age related to the Yanshanian movement and indicate a short thermal event in the Middle Jurassic; the K–Ar ages of the < 2 µm fractions (210‐308 Ma) are interpreted as mixed ages of detrital material and authigenic illites. The K–Ar ages of both < 0.2 µm and < 2 µm fractions of a Middle Cambrian sample (368 Ma and 419 Ma) correspond to the ages of the metamorphism and earliest granite intrusion in the northern Caledonian Qinling fold zone (380‐420 Ma) and show a thermal event during Silurian–Devonian time.
Valid publication of the name Helicia falcata (Proteaceae)
Authors: Jiang Nan , Lin Xia , Guan Kai‐Yun , Yu Wen‐Bin
Published: August 2010

Helicia falcata C. Y. Wu was not validly published in 1977 because two gatherings, one flowering and one fruiting, were simultaneously designated as types in the protologue. This name is validated here by designating the flowering specimen as the holotype.
Microendoscopic discectomy for lumbar disc herniation in the elderly
Authors: Matsumoto M , Ishii K , Watanabe K , Tsuji T , Takaishi H , Nakamura M , Toyama Y , Chiba K
Published: August 2010

Introduction: The purpose of this study was to elucidate the feasibility of microendoscopic discectomy (MED) for the treatment of lumbar disc herniation in elderly patients over the age of 65.

Methods: The elderly group consisted of 44 patients (27 men and 17 women; mean age, 69.6 years; mean follow‐up, 27.7 months) with sciatic pain caused by lumbar disc herniation who were treated using MED. The younger group was comprised of 44 sex‐matched patients younger than 65 years. The younger group also had lumbar disc herniation treated with MED and served as the control group. The clinical outcomes were evaluated using the Japanese Orthopaedic Association score for low back pain (JOA score).

Results: The results revealed that the good surgical outcomes achieved in the younger group were also achieved in the elderly group (JOA scores: 14.8 ± 4.1 in the younger group before surgery versus 13.0 ± 3.2 in the elderly group; 26.0 ± 2.4 at follow‐up versus 25.5 ± 2.7; recovery rates of JOA scores: 78.3 ± 17.8% versus 77.9 ± 16.6%, respectively). The mean surgical time was 78.3 ± 31.0 min in the elderly group and 69.2 ± 22.9 min (P=0.12) in the younger group; the blood loss was 33.9 ± 71.9 cc and 28.0 ± 37.8 cc (P=0.63), respectively. Complications included a dural tear in two elderly patients, and postoperative discitis and hematoma in one elderly patient each: all of these complications were managed successfully.

Conclusion: The results of this study demonstrated that MED is a feasible minimally invasive surgical option for elderly patients with lumbar disc herniation.