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Micro-textures in plagioclase from 1994-1995 eruption, Barren Island Volcano: Evidence of dynamic magma plumbing system in the Andaman subduction zone

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Geoscience Frontiers 2014年第1期5卷 113-126页

作者： M.L.Renjith Marine and Coastal Survey division Geological Survey of India 4th Floor C-Block Kendriya Bhavan Kakkanadu CochinKerala 682037 India

A systematic account of micro-textures and a few compositional profiles of plagioclase from high-alumina basaltic aa lava erupted during the year 1994-1995, from Barren Island Volcano, NE India ocean, are presented for the first time. The identified micro-textures can be grouped into two categories：（i） Growth related textures in the form of coarse/fine-sieve morphology, fine-scale oscillatory zoning and resorption surfaces resulted when the equilibrium at the crystal-melt interface was fluctuated due to change in temperature or H20 or pressure or composition of the crystallizing melt; and （ii） morphological texture, like glomerocryst, synneusis, swallow-tailed crystal, microlite and broken crystals, formed by the influence of dynamic behavior of the crystallizing magma （convection, turbulence, degassing, etc.）. Each micro-texture has developed in a specific magmatic environment, accordingly, a first order magma plumbing model and crystallization dynamics are envisaged for the studied lava unit. Magma generated has undergone extensive fractional crystallization of An-rich plagioclase in stable magmatic environment at a deeper depth. Subsequently they ascend to a shallow chamber where the newly brought crystals and pre-existing crystals have undergone dynamic crystallization via dissolution-regrowth processes in a convective self- mixing environment. Such repeated recharge-recycling processes have produced various populations of plagioclase with different micro-textural stratigraphy in the studied lava unit. Intermittent degassing and eruption related decompression have also played a major role in the final stage of crystallization dynamics.

关键词： Micro-texture Plagioclase Magma chamber process Barren Island Volcano Andaman subduction zone

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Middle and Late Tertiary Palaeogeography and Palaeoenvironment on the Northern Continental Margin of the South China Sea

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Acta Geologica Sinica(English Edition) 1990年第2期64卷 211-222页

作者： Duan Weiwu Huang Yongyang Guangzhou Marine geological Survey, Ministry of Geology and Mineral Resources, Guangzhou, Guangdong Chinese Academy of geological Sciences Beijing

Based essentially on research results of calcareous nannofossils, combined with some other microfossil da-ta and several secondary depositional breaks, this paper discusses the criteria of division and comparison of themiddle and late Tertiary marine sediments, palaeogeographical and palaeoenvironmental evolution andpalaeoclimates on the northern continental margin of the South China Sea, comprising the Tainan basin, PearlRiver Mouth basin. Southeast Hainan basin and Beibu Gulf basin. Study shows that the upper Oligocene toPliocene strata in the whole area consist essentially of marine sediments except in the Beibu Gulf basin. Theyinclude littoral. neritic and deltaic sediments as well as carbonate rock-bioherm limestone. The sea advancedfrom southeast to northwest. During the transgression there appeared three culminations coinciding to thestages of deposition of nannofossil zones NN4-5, NN11 and 13-15.

关键词： Middle and Late Tertiary Palaeogeography and Palaeoenvironment on the Northern Continental Margin of the South China Sea

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Groundwater System division and Description of Asia

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Acta Geologica Sinica(English Edition) 2016年第4期90卷 1434-1443页

作者： ZHANG Fawang YI Qing CHENG Yanpei YUE Chen DONG Hua Institute of Karst Geology Chinese Academy of Geological Sciences Institute of Hydrogeology and Environmental Geology Chinese Academy of Geological Sciences

Based on landform, climate, river system, geological structure and hydrogeological structure and from the perspective of systematology, the groundwater system of Asia can be divided into 36 secondary groundwater systems under 11 primary ones by the intercontinental scale. This forms part of the work of the groundwater series map of Asia, which is compiled according to groundwater system division and evaluation of the total amount and types of aquifer, reflecting the large-scale features of groundwater resources in Asia. Systematic profiling of groundwater in this way provides a scientific basis for groundwater exploitation planning and management in Asia, and avoiding disputes over groundwater resources and the environment among Asian countries.

关键词： Asia groundwater system climate and topography division

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Climatology, trend of aerosol-cloud parameters and their correlation over the Northern Indian Ocean

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Geoscience Frontiers 2023年第4期14卷 173-186页

作者： Harshbardhan Kumar Shani Tiwari Academy of Scientific and Innovative Research(AcSIR) Ghaziabad201002India Aerosol and Cloud Research Lab Geological Oceanography DivisionCSIR–National Institute of OceanographyGoa403004India

Aerosols are one of the important atmospheric constituents and exert indirect impact on climate through the modification of microphysical and radiative properties of clouds that in turn perturb the precipitation ***,the long term quantification of changes in aerosol and cloud characteristics and their interactions on both temporal as well as spatial scale will provide a crucial information for the better assessment of future climate *** present study,18 years(2003-2020)MODerate Resolution Imaging Spectro-radiometer(MODIS)derived aerosol-cloud dataset over the Northern Indian Ocean(NIO)were analysed to assess climatology and trend of aerosol,cloud characteristics and their *** found a strong heterogeneity in spatio-temporal variation of aerosol and cloud parameters over the NIO that are more prominent for the coastal *** climatological mean of aerosol loading is found high(AOD≥0.5)over the outflow region along the Indian sub-continent and low(AOD≤0.2)over the northern equatorial open *** climatological mean of cloud properties shows dominance of optically thicker deep convective(CTP700 hPa and CTT>273 K)over the northwestern Arabian Sea(AS).Similarly,bigger effective radii(>17µm)observed along the equatorial open ocean whereas smaller CER(0.

关键词： Aerosol Cloud properties Northern Indian Ocean Climatology Trend Correlation

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Existence and implications of hop-17(21)-enes in the lower Cretaceous of the Saihantala Sag, Erlian Basin, China

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Petroleum Science 2012年第2期9卷 154-160页

作者： Luo Qingyong Yu Shijun Liu Yan Zhang Yanqi Han Hui Qi Lin Zhong Ningning State Key Laboratory of Petroleum Resources and Prospecting China University of PetroleumBeijing 102249China Jiangxi division of geological Prospecting Center SinomaShang-raoJiangxi 334000China

C31- to C35-hop-17（21）-enes are identified by gas chromatography-mass spectrometry （GC-MS） analysis to exist as double isomers in most samples of the Aershan Formation and members 1 and 2 of the Tenggeer Formation from well SH3. Comprehensive organic geochemistry and organic petrology study indicates that algae and bacteria are the main biological source of lower Cretaceous sediments in the Saihantala Sag, and this is in accordance with the existence of hop-17（21）-enes. The similar distributions of hop-17（21）-enes and hopanes of these samples indicate that hop-17（21）-enes were transformed into hopanes through hydrogenation during diagenesis processes. The existence of hop-17（21）-enes means that not only the formation of organic matter is related to an anoxic environment and a biological source of algae and bacteria, but also hop-17（21）-enes are direct indicators of hydrocarbon rock at an immature to low-maturity stage. High hydrocarbon conversion ratio, algae and bacteria source and a high abundance of organic matter suggest that the Saihantala Sag has the potential to generate immature to low-maturity oil, which may be of great significance for oil exploration in the Erlian Basin.

关键词： Biomarkers hop-17(21)-ene biological source immature oil Erlian Basin

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Status of Stratigraphy Research in China

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Acta Geologica Sinica(English Edition) 2016年第4期90卷 1069-1081页

作者： YAO Jianxin BO Jingfang HOU Hongfei WANG Zejiu MA Xiulan LIU Fengshan HU Guangxiao JI Zhansheng WU Guichun WU Zhenjie LI Suping GUO Caiqing LI Ya Key Laboratory of Stratigraphy and Paleontology Ministry of Land and Resources Institute of GeologyChinese Academy of Geological Sciences Beijing 100037 China Chinese Academy of geological Sciences Beijing 100037 China China geological Survey Beijing 100037 China

Scientific research and productive practice for earth history are inseparable from the accurate stratigraphic framework and time framework. Establishing the globally unified, precise and reliable chronostratigraphic series and geological time series is the major goal of the International Commission on Stratigraphy （ICS）. Under the leadership of the ICS, the countries around the world have carried out research on the Global Standard Stratotype-section and Points （GSSPs） for the boundaries of chronostratigraphic systems. In the current International Chronostratigraphic Chart （ICC）, 65 GSSPs have been erected in the Phanerozoic Eonothem, and one has yet been erected in the Precambrian Eonothem. Based on the progress of research on stratigraphy especially that from its subcommissions, the ICS is constantly revising the ICC, and will publish a new International Stratigraphic Guide in 2020. After continual efforts and broad international cooperation of Chinese stratigraphers, 10 GSSPs within the Phanerozoic Eonothem have been approved and ratified to erect in China by the ICS and IUGS. To establish the standards for strafigraphic division and correlation of China, with the support from the Ministry of Science and Technology, the National Natural Science Foundation of China and the China geological Survey, Chinese stratigraphers have carried out research on the establishment of Stages in China. A total of 102 stages have been defined in the ＂Regional Chronostratigraphic Chart of China （geologic time）＂, in which 59 stages were studied in depth. In 2014, the ＂Stratigraphic Chart of China＂ was compiled, with the essential contents as follows： the correlation between international chronostratigraphy and regional chronostratigraphy of China （geologic time）, the distributive status of lithostratigraphy, the characteristics of geological ages, the biostratigraphic sequence, the magnetostratigraphy, the geological events and eustatic sea-level change during every geological stage.

关键词： Stratigraphy research process status China.

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The conjunction of factors that lead to formation of giant gold provinces and deposits in non-arc settings

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Geoscience Frontiers 2016年第3期7卷 303-314页

作者： David I.Groves Richard J.Goldfarb M.Santosh Centre for Exploration Targeting UWA State Key Laboratory of geological Processes and Mineral Resources China University of Geosciences U.S.geological Survey Denver Federal Center Centre for Tectonics Resources and Exploration Dept. of Earth SciencesUniversity of Adelaide division of Interdisciplinary Science Faculty of ScienceKochi University

It is quite evident that it is not anomalous metal transport,nor unique depositional conditions,nor any single factor at the deposit scale,that dictates whether a mineral deposit becomes a giant or not.A hierarchical approach thus is required to progressively examine controlling parameters at successively decreasing scales in the total mineral system to understand the location of giant gold deposits in non-arc *** giant orogenic,intrusion-related gold systems（IRGS） and Carlin-type gold deposits and iron oxide-copper-gold（IOCG） deposits,there are common factors among all of these at the lithospheric to crustal *** are sited in giant gold provinces controlled by complex fundamental fault or shear zones that follow craton margins or,in the case of most Phanerozoic orogenic giants,define the primary suture zones between tectonic *** provinces of IRGS,IOCG,and Carlin-type deposits require melting of metasomatized lithosphere beneath craton margins with ascent of hybrid lamprophyric to granitic magmas and associated heat flux to generate the giant *** IRGS and IOCG deposits require direct exsolution of volatile-rich magmatic-hydrothermal fluids,whereas the association of such melts with Carlin-type ores is more indirect and *** orogenic gold provinces show no direct relationship to such *** from metamorphic fluids,but show an indirect relationship to lamprophyres that reflect the mantle connectivity of controlling first-order *** contrast to their province scale similarities,the different giant gold deposit styles show contrasting critical controls at the district to deposit *** orogenic gold deposits,the giants appear to have formed by conjunction of a greater number of parameters to those that control smaller deposits,with resultant geometrical and lithostratigraphic complexity as a guide to their *** are few giant IRGS due to their inferior fluid-flux systems relative to orogeni

关键词： Giant gold deposits Orogenic gold Carlin deposits Iron oxide-copper-gold deposits Intrusion-related gold systems Lithosphere

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Practical application of failure criteria in determining safe mud weight windows in drilling operations

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Journal of Rock Mechanics and Geotechnical Engineering 2014年第1期6卷 13-25页

作者： R.Gholam A.Moradzadeh V.Rasoul J.Hanach Department of Mining Petroleum and Geophysics Shahrood University of Technology Departmentof Petroleum Engineering Curtin University geological division Iranian Offshore Oilfield Company

Wellbore instability is reported frequently as one of the most significant incidents during drilling *** of wellbore instability includes estimation of formation mechanical properties and the state of in situ *** this analysis,the only controllable parameter during drilling operation is the mud *** the mud weight is larger than anticipated,the mud will invade into the formation,causing tensile failure of the *** the other hand,a lower mud weight can result in shear failures of rock,which is known as borehole *** predict the potential for failures around the wellbore during drilling,one should use a failure criterion to compare the rock strength against induced tangential stresses around the wellbore at a given mud *** Mohr–Coulomb failure criterion is one of the commonly accepted criteria for estimation of rock strength at a given state of ***,the use of other criteria has been debated in the *** this paper,Mohr–Coulomb,Hoek–Brown and Mogi–Coulomb failure criteria were used to estimate the potential rock failure around a wellbore located in an onshorefield of *** log based analysis was used to estimate rock mechanical properties of formations and state of *** results indicated that amongst different failure criteria,the Mohr–Coulomb criterion underestimates the highest mud pressure required to avoid breakouts around the *** also predicts a lower fracture gradient *** addition,it was found that the results obtained from Mogi–Coulomb criterion yield a better comparison with breakouts observed from the caliper logs than that of Hoek–Brown *** was concluded that the Mogi–Coulomb criterion is a better failure criterion as it considers the effect of the intermediate principal stress component in the failure analysis.

关键词： Mud weight windows Failure criterion Breakout Fracturing Intermediate principal stress

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A composite fall-slippage model for cliff recession in the sedimentary coastal cliffs

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Geoscience Frontiers 2017年第4期8卷 903-914页

作者： K.S.Sajinkumar J.P.Kannan G.K.Indu C.Muraleedharan V.R.Rani Department of Geology University of Kerala Department of geological & Mining Engineering & Sciences Michigan Technological University geological Survey of India Central Ground Water Board

A composite fall-slippage model is proposed in this study for the Tertiary sedimentary coastal cliffs of Varkala in the western coastal tract of Peninsular India which are retreating landwards due to the combination of several *** fall model in the present study accounts both spring seepage and wave action,resulting in undercutting and this fall affects only the topmost laterite and the just below sandstone in the *** in this area affects all the litho-units and hence the geologic characteristics of all the litho-units are considered for developing the slippage *** mathematically derived model can be used in other cliffs exhibiting the same morphology as well as the one controlled by the same influencing *** model differs from other models in incorporating multi-lithounits as well as *** cliffs form a part of the aspiring geopark in the Global Geopark Network and hence a study on the cliff recession is a pressing requirement.

关键词： Coastal cliff Coastal landslide Cliff recession model Varkala

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Municipal solid waste landfill site selection for the city of Sanliurfa-Turkey:an example using MCDA integrated with GIS

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International Journal of Digital Earth 2012年第2期5卷 147-164页

作者： M.Irfan Yesilnacar M.Lutfi Suzen Basak Sener Kaya Vedat Doyuran Department of Environmental Engineering Harran UniversityS¸anliurfaTurkey Department of geological Engineering Middle East Technical UniversityAnkaraTurkey Colorado School of Mines Division of EngineeringGoldenCOUSA

A municipal solid waste(MSW)management system needs solid waste management(SWM)techniques where the presence of a sanitary landfill is *** of the most important issues of sanitary landfilling is to locate the facility to an optimal *** the versatility and case-dependent nature of conventional expert-based site selection procedures,the number of sites to be chosen increases with increased population forcing a number of ***quently,constraints and environmental regulations mechanically mask unsuitable areas,leaving very little areas to be *** turns the situation into a challenging issue for a geographical information system(GIS)used with multicriteria decision analysis(MCDA),to select optimal *** study aims to apply MCDA integrated with GIS to select possible sites of a MSW landfill with the same expert and same cognitive parameters while compared with the already present *** of this study revealed that conventional expert-based methods could not always evaluate all constraints at the same time and map reproduction is limited when parameter maps are changing rapidly in *** order to produce cognitive and reproducible analyses,GIS with MCDA integration offers a good solution for site selection issue and forms a good alternative for conventional methods.

关键词： municipal solid waste(MSW) landfill site selection geographical information systems(GIS) multi-criteria decision analysis(MCDA)

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