Discussion on the Transform of Paleotethys into the Pacific

1.IntroductionTherehavebeenalargeamountofresearchesontheN--SextendingPaleotethysinthePaleozoicandonthemodernE--WextendingPacificOceanintheCenozoic.ButfewhavetouchedonhowthePaleotethysevolvedintothemodemPacific,andthereareonlyguessesaboutthesitllationofthePaleo--Pacificbetweenthetwostages.ThispapertriestodiscussthedynamicmechanismofthePaleo--PacificplateandthecharacteristicsoftheactivitiesofEastAsiacontinentalmarginintheMesozoicthroughtheterranesfromPaleotethysremainingintheEastAsiacont…     

A Study on the Kunyang Aulacogen

The Kunyang Aulacogen is a continental rift which initiated at the beginning of the Middle Proterozoic. Itwas generated on the rigid continental crust represented by the crystalline Kangding Complex, and is boundedby two N-S-trending deep faults--Anninghe-Luzhijiang Fault and Xiaojiang Fault. Its early stage of rupturewas characterized by alkalinc mafic igneous activities in the Dahongshan Group and Hekou Group. Duringthe later tensile-depression stage the aulacogen evolved into a graben where scdimentation of the KunyangGroup took place. The sedimentary sequence comprises terrestrial red beds, algal dolomite, marine black shaleand carbonate rocks which are quite typical of rift sedimentary association, and contains stratabound copperdeposits of the well-known Dongchuan type.     

Experimental Study on the Effects of Organic Acids on the Dissolution of REE in the Weathering Crust of Granite

The results of REE leached by some organic acids with various concentrations and water/rock ratios for different durations from a mixed samples of the weathering crust of a granite in Gonghe,Guangdong,China,showed that:1)the contents of REE leached increase with increasing concentrations of the organic acids;2) the contents of REE leached by 0.01mol/L organic acids increase with increasing water/rock ration;3) the interaction between the organic acids and the samples enhances the pH value of the medium and the contents of REE leached tend to increase with decreasing pH value;and 4) compared with those leached by ammonia sulfate,the REE leached by the organic acids are characterized by a weaker negative C e anomaly,a stronger negative Eu anomaly,and lower(La/Sm)N and (Gd/Yb)N ratios,indicating that the organic acids have made contributions to the fractionation of REE in the weathering crust.     

Kinetic research on the sorption of aqueous cadmium on carbonate hydroxyapatite

The sorption of aqueous cadmium on carbonate-hydroxyapatite （CHap） is a complicated non-homogeneous solid/water reaction, From kinetic point of view, it can be described by two stages： at the earlier stage, reaction rate is so fast that its kinetic course is intricate, and at the later stage, the rate of reaction becomes slow and the process of reaction accords with one order reaction kinetic equation. Experimental results show that the relationship between reaction rate constant kl and temperature T accords to Arrhenius Equation, and the activation energy of sorption （Ea） is 6.075 J/mol and frequency factor （A） is 220 s^-1. At the same time, reaction rate constant kl increases with decreasing Cd^2＋ initial concentration, on the contrary, with increasing pH and CHap dosage.     

A study on the bio-hydro mechanical effects of the tree roots on the Agaclı coal reclaimed – forested land

The research area that is in the north of Istanbul (Turkey) and it is a land of open pit coal mining residuals reclaimed and turned to forest in 1988–1989. The materials that are open pit mine spoils are formed by sandy loam, sandy clay loam, heavy loam and clay (noncalcareous Pliocene I sediments). Pseudoacacia (Robinia pseudoacacia), Maritima Pine (Pinus pinaster) and Stone Pine (Pinus pinea) are planted on these materials. The aims of this research were to determine the strength of the material provided by tree roots and evaluate the performance of the forestation practices at lands especially where open pit coal mining spoil (residual) materials piled up. The research has been performed at two stages. The first one was hydro-mechanical effect concerned about material moisture depletion as a result of transpiration and the second one was bio-mechanical effects due to strength parameters of the roots and their growth pattern within the material. All results were evaluated in relation to tensile strength and displacement curves due to pre and post failure behaviors of materials and root systems. The results showed the increase of the displacement of the material was the significant indicator of the bio-mechanics tensile strength of the material provided by the tree roots. The fast growing type of tree roots have stabilized the material up to a depth for 80–100 cm by covering the coal residual materials within 12 years.     

Research on the Terrane Tectonics in China

This paper summarizes the latest advances in research on the terrane tectonics of China.The terranes of China distributed around various plates may be divided into four terrane belts of different ages and sizes.i.e.,the East China,Northwest China,Southwest China and Qilling-Dabie terrane belts.Among them,the East China belt may be subdivided into three composite terrane groups;each terrane proup is composed of several terranes that were formed roughly at the same time and have distince geologic histories.The accretion of China‘s terranes involver three types;the collision type,the flake-thrusting type,and the docking type.The results of the lates study in the five widening fields and some advances in the methods of research on the terrane tectonics in China are presented in the present paper.     

Journal Citation Reports on the Web简介

Journal Citation Reports on the Web依据来自ISI Web of Science(Science Citation Index Expanded和Social Sciences Citation Index)中的引文数据,Journal Citation Reports(?)提供可靠的统计分析方法,对全球学术期刊进行客观、系统地评估,帮助用户以定量的方式了解全球的学术期刊,并且通过这些分析数据可以了解某学术期刊在相应研究领域中的影响力。其特点为:从世界上经同行评议的学术期刊中,筛选出被引次数最高近8000种期刊,这些期刊涵盖了200多门学科;提供自1997年以来的期刊引文统计分析     

Isotope-geochemical constraints on the formation of the early Earth’ crust

Analysis of isotope-geochemical data obtained for the early crustal complexes of the Earth provided constraints on the formation time, scales of development, and geochemical features of protocrust. Most informative were isotope-geochemical and geochemical data on the oldest zircons with ages up to 4.4 Ga, short-lived ¹⁴⁶Sm/¹⁴²Nd isotope system, and lead isotope composition of the oldest rocks of Greenland. The presence of positive ¹⁴²Nd anomaly in the rocks of West Greenland and negative anomaly in the amphibolites of the oldest Nuvvuagittuq greenstone belt of the Superior province (O’Neil et al., 2008) indicates the early differentiation of the Earth material into depleted mantle and enriched (basaltic) crust (Caro et al., 2006; Benett et al., 2007a, b; O’Neil et al., 2008). Pb-Pb isotopic systematics of the oldest crustal rocks from West Greenland and Labrador testifies that high μ enriched crust (²³⁸U/²⁰⁴Pb = 10.9) of basaltic composition already existed 3.9 Ga ago (Kamber et al., 2003). Based on isotope-geochemical and geochemical features of the oldest zircons in the Late Archean greenstone belts of the Yilgarn block (Western Australia), the crust of intermediate-felsic composition and water on the Earth’s surface already existed 4.4 Ga ago (Wilde et al., 2001).     

New Data on Crystallization Conditions of Monzodiorite—Granite Massifs on the Eastern Slope of the Urals

The geological structure of monzodiorite—granite massifs (Stepninskii, Biryukovskii, Vandyshevskii, and Uiskii) of the Stepninskii complex extending as a chain of intrusive bodies crossing the submeridional structures of the Ural Fold Belt is described. These granite massifs are ascribed to the Permian and, as suggested, are related to a mantle plume. Based on the results of studying melt and gas—liquid inclusions in quartz from granitoids, it was established that the rock crystallization depth in the given series of massifs decreases gradually in the northwesterly direction from hypabyssal to hypabyssal—subsurface facies. It is shown that leucocratic and aplitic varieties of granites with a higher level of fluid content have rare-metal metallogenic specificity and are promising in the search for W—Mo ore mineralization.     

Preliminary Study on the PGE Geochemistry of the Permian Basalts in the Jinping Area

INTRODUCTIONIn comparison with studies on the geochemistryof the REE and trace elements of the Emeishan Per-mian basalts ,there has been onlyli mited research onthe platinum group elements ( PGE) . Preli minarystudies have been carried out on the PGE geochemis-try of the basalts in the Emeishan area ( QingyingPower Station profile) and Xinjie area (Zhang andLi ,1998) ,andinthe Shuicheng and Weining areasinGuizhou (Li et al .,2003) . There are no PGEanaly-sis data of the basaltsin…     

Ar-Ar Dating on the Metallogenesis of the Dongchuang Gold Deposit in the Xiaoqinling Area

The Dongchuang gold deposit in the Xiaoqinling area is an orogenic-type lode gold deposit. It is one of the few superlarge (>100 t Au) deposits in China. Although it has been argued that it was formed in the Mesozoic, related isotopic age data have not been reported in previous studies. Based on detailed geological study, the authors have carried out isotopic dating on various metallogenic generations. The ore-forming process of the Dongchuang gold deposit consists of four stages: coarse-grained pyrite-bearing quartz veins (stage Ⅰ), fine-grained pyrite-quartz veinlets (stage Ⅱ), multi-sulfides (stage Ⅲ) and carbonate-quartz veinlets (stage IV). Ar-Ar dating on mineral separates of stages Ⅰ, Ⅱ and Ⅲ yields plateau ages of 142.9±2.9 Ma, 132.2±2.6 Ma and 128.3±6.2 Ma, respectively. Sericite separates from stage Ⅱ assemblage also yield an Ar-Ar isochron age of 132.6±2.7 Ma, similar to the Ar-Ar plateau age. These results suggest that the Dongchuang gold deposit was mainly formed during 143-128 M     

Why did life develop on the surface of the Earth in the Cambrian?

Life was limited for most of Earth's history, remaining at a primitive stage and mostly marine until about 0.55 Ga. In the Paleozoic, life eventually exploded and colonized the continental realm. Why had there been such a long period of delayed evolution of life? Early life was dominated by Archaea and Bacteria,which can survive ionizing radiation better than other organisms. The magnetic field preserves the atmosphere, which is the main shield of UV radiation. We explore the hypothesis that the Cambrian explosion of life could have been enabled by the increase of the magnetic field dipole intensity due to the solidification of the inner core, caused by the cooling of the Earth, and the concomitant decrease with time of the high-energy solar flux since the birth of the solar system. Therefore, the two phenomena could be responsible for the growth and thickening of the atmosphere and the development of land surface life.     

Report on the Third IGCP-649 International Workshop on the Mayarí-Baracoa Ophiolites and Chromitites, Cuba

<正>During April 3~(rd)–14~(th),the Third International Ophiolite Workshop of the International Geoscience Programme"Diamonds and Recycled Mantle"(IGCP-649)was successfully held in Havana,Cuba(Fig.1a).After the workshop,participants participated in a field trip to the Mayarí-Baracoa ophiolites and related chromitites in     

Study on the Safety of the Foundation Rock Masses in the Tangkou Bank of the Taipinghu Bridge

The Taipinghu Bridge is an important project, and the safety of rock masses of its foundation is very crucial. This article analyzes the potential causes of the deformation of the rock masses of the bridge foundation, and uses the Fast Lagrangian Analysis of Continua to analyze the geologic model. The simulating process shows that no mater in the excavating process or in the loading process the rock masses are suit for the engineering. The modeling and analyzing process can be used for reference.     

Active Tectonics of the Longmen Shan Region on the Eastern Margin of the Tibetan Plateau

There is a massive amount of geomorphic evidence for active tectonics in the Longmen Shan at the eastern margin of the Tibetan plateau. We have surveyed some typical geomorphic markers including the Wenchuan-Maowen, Beichuan-Yingxiu and Pengxian-Guanxian faults, terrace offsets, scarps, fault-controlled saddles, dextral shutter ridges, dextral channel offsets, graben, shatter belts, and pull-apart basins. Electron spin resonance （ESR） and thermoluminescence（TL） ages were obtained using silty sand taken from below the surface of the sediments. According to these data, we calculated the rates of thrusting and strike-slip, and the results indicate that Cenozoic tectonic shortening at the plateau margin is minor with the rate of thrusting less than 1.10 mm/a and the rate of strike-slipping less than 1.46 mm/a. The Longmen Shan is a zone of NNE-trending dextral shear with slip-dip ratio of 6：1-1.3：1. From NW to SE, the thrust component becomes smaller, whereas the strike-slip component becomes larger.     

Study on the Metallogenic Chronology of the Gold Deposits in Jiaoliao Area

Please refer to the attachment(s) for more details     

Notes on the Adjustment of the English Edition of Acta Geologica Sinica

Acta Geologica Sinica (formerly the Bulletin of the Geological Society of China) beganpublication in 1922, and was published mainly in English through 1952. Since then, thejournal has been published in Chinese with English abstracts. In March 1988, ActaGeologica Sinica appeared in English language translation. The journal is a full translationof the Chinese edition, and follows the Chinese edition by two issues.     

Notes on the Adjustment of the English Edition of Acta Geologica Sinica

Acta Geologica Sinica (formerly the Bulletin of the Geological Society of China) beganpublication in 1922, and was published mainly in English through 1952. Since then, thejournal has been published in Chinese with English abstracts. In March 1988, Acta