检索结果-南通市图书馆

Multi-Elemental chemostratigraphy,Sequence Development,Depositional History,and Environmental Importance of Early Eocene Red Beds(Kuldana Formation)in NW Himalayas,Pakistan

引用

Journal of earth Science 2024年第2期35卷 349-375页

作者： Amir Shahzad George Kontakiotis Thierry Adatte Khawaja Shoaib Ahmed Muhammad Tayyib Riaz Hammad Tariq Janjuhah Evangelia Besiou institute of geology University of Azad Jammu and KashmirMuzaffarabad13100Pakistan department of Historical geology-Paleontology Faculty of Geology and GeoenvironmentSchool of Earth SciencesNational and Kapodistrian University of AthensPanepistimiopolisZografou15784Greece institute of earth sciences(ISTE) University of LausanneLausanneCH-1015Switzerland department of geology Shaheed Benazir Bhutto UniversitySheringalPeshawar18050Pakistan

The Eocene Kuldana Formation(KF)in the Yadgar area of Pakistan,comprises a diverse range of sedimentary facies,including variegated red beds of shales,mudstones,and sandstones,as well as interbedded limestone and *** this study,we conducted an integrated micropaleontological,sedimentological,mineralogical,and geochemical investigation to determine the depositional setting,biochronology,provenance,and paleoclimate of the *** study identified six lithofacies and six microfacies,which indicate a variety of environments ranging from floodplains and channels to the margins and shallow marine *** nannofossil biostratigraphy places the KF in the Early Eocene,more precisely the NP10 zone(Ypresian),and the fossil zone of benthic foraminifera classifies the study section as the Shallow Benthic zone SBz-8(Middle Ilerdian 2).In terms of petrography,the KF sandstone was classified as litharenite and feldspathic litharenite,while the QtFL diagram suggests a recycled *** proxies indicate an oxidizing environment,a high-to-low regular sedimentation rate,moderate-to-intense chemical weathering in the source region,and a warm-humid to dry climate during the deposition of ***,the findings suggest that the deposition of KF marks the end of Neo-Tethys due to the Early Eocene Indian–Kohistan collision and that the uplifting of the Himalayas provided the source for the deposition of KF in the foreland *** study provides new insights into the depositional environment,biochronology,provenance,and paleoclimate of KF,and highlights the potential for red beds as reliable indicators of oxygenation levels in proximity to mineral deposits.

关键词： sedimentary microfacies Paleocene–Eocene thermal maximum stratigraphic correlations paleoenvironmental reconstruction nannofossils paleontology

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Towards Understanding Paleosols in Southern Levantine Eolianites:Integration of Micromorphology,Environmental Magnetism and Mineralogy

引用

Journal of Mountain Science 2009年第2期6卷 113-124页

作者： Alexander Tsatskin Tatyana S.Gendler Friedrich Heller Igal Dekman Gitti L.Frey Laboratory of geology Zinman Institute of Archaeology University of HaifaHaifa 31905 Israel United institute of Physics of the earth RAS Bolshaya Gruzinskaya 10Moscow 123810 Russia Institut für Geophysik ETH ZürichCH-8092 Zürich Switzerland department of Materials Engineering Technion Haifa 32000 Israel

The paper addresses the controversial question of the role of clay-sized dust in the formation of paleosols in coastal eolianites, Israel. At the Habonim type section, the pedocomplex dated by archaeology and luminescence to 45-135 ka ago shows at least three paleosols, not separated by non-soil sediments. The oldest reddish paleosol （apparently related to MIS 5） is magnetically enhanced, leached from carbonates, with signs of bioturbation and strongly aged clay coatings. The reddening is due to very fine, -20 nm, poorly crystallized, superparamagnetic （SP） hematite, as determined by Mossbauer studies. In subsoil, lithorelics of eolianite are found. Over time, the soil surface aggraded due to accelerated fine dust accumulation alongside local slope wash. On younger materials formed magnetically depleted vertisols, dominated by smectite-type expandable paramagnetic clays. In thin sections, vertisols exhibit strong stipple-speckled and striated b-fabric due to shrink-swell processes, impregnative calcite nodules and Fe-Mn redistribution. The uppermost hydric vertisol shows the strongest expression of juxtaposed features of recurrent calcite and Fe precipitation. This paleosol developed on colluvial soil materials, as evidenced by mixing of clay coated and uncoated grains of quartz and calcite allochems. M6ssbauer spectra show high amounts of Fe（III） incorporated in the clay structure, low amounts of SP goethite and absence of SP hematite. Whilst magnetic susceptibility drops in vertisols to minimal values, increase. The latter along ferrimagnetie grain sizes with differences in the hierarchy of microfabric features is taken as indication for lithologic discontinuities which may have resulted from continuous, albeit variable and low-intensity, input of eolian clay from both remote Saharan and local sources, roughly dated to the earlier to middle part of the Last Glacial.

关键词： Coastal sand loess deposition microfabrie hierarchy magnetic enhancement paramagnetic phyllosilicates MSssbauer effect

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Melt Evolution above a Spontaneously Retreating Subducting Slab in a Three-Dimensional Model

引用

Journal of earth Science 2011年第2期22卷 137-142页

作者： Taras Gerya David A Yuen department of earth sciences Swiss Federal Institute of Technology(ETH Zurich)CH-8092 ZurichSwitzerland Adjunct Professor of geology department Moscow State University department of geology and Geophysics and Minnesota Supercomputing institute University of MinnesotaMinneapolisMN 55415USA

Dehydration of the subducting slab favors the melting of the surrounding mantle. Water content and melt evolution atop a spontaneously retreating subducting slab are reported in a three- dimensional （3-D） model. We find that fluids, including water and melts in the rocks, vary substantially along the trench, which cannot be found in two-dimensional （2-D） models. Their maxima along the subducting slab are mainly located at about 50 to 70 and 120 to 140 kin. Volumetric melt production rate changes spatially and episodically atop the slab, which may reflect the intensity and variations of volcanoes.

关键词： subduction water and melt three-dimensional model.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Electro-Pulse-Boring(EPB): Novel Super-Deep Drilling Technology for Low Cost Electricity

引用

Journal of earth Science 2015年第1期26卷 37-46页

作者： Hans O.Schiegg Arild Rdland Guizhi zhu David A.Yuen SwissG eo Power AG Stadtturmstrasse 19 CH-5401Switzerland department of Petroleum Engineering and Applied Geophysics Norwegian University of Science and Technology7491 TrondheimNorway department of earth sciences ETH-Zurich CH-8092Switzerland department of earth sciences and Minnesota Supercomputing institute University of MinnesotaMinneapolis MN 55455USA School of Environmental Studies China University of Geosciences

The inexhaustible heat deposit in great depths （5-10 km） is a scientific fact. Such deposit occurs around the globe. Thereby, everybody is enabled to generate autonomously clean and renewable energy, ample electricity and heat. The economical exploration and exploitation of this superdeep geothermal heat deposit requires a novel drilling technique, because the currently only deep drilling method （Rotary） is limited to about 5 km, due to the rising costs, depending exponentially on depth. Electro-pulse-boring （EPB） is a valuable option to Rotary drilling. EPB, originally investigated in Russia, is ready to be developed for industrialization. The feasibility of EPB is proven by many boreholes drilled up to 200 m in granite （crystalline）. Estimates show outstanding low costs for drilling by EPB： 100 E/m for a borehole with a large diameter （φ） such as 20 （50 cm）, independent on depth and applicable likewise for sediments and crystalline rocks, such as granite. The current rate of penetration （ROP） of 3 m per hour is planned to be augmented up to 35 m per hour, and again, irrespective whether in sedimentary or crystalline formations. Consequently, a 10 km deep borehole with φ 50 cm will ultimately be drilled within 12 days. EPB will create new markets, such as：（i） EPB shallow drilling for geotechnics, energy piles, measures in order to mitigate natural hazards, etc., （ii） EPB deep drilling （3-5 km） for hydro-geothermics, exploration campaigns etc. and （iii） EPB super-deep drilling （5-10 km） for petro-geothermies, enabling the economic generation of electricity. The autonomous and unlimited supply with cost efficient electricity, besides ample heat, ensures reliably clean and renew- able energy, thus, high supply security. Such development will provide a substantial relief to cope with the global challenge to limit the climate change below 2 ℃. The diminution of fossil fuels, due to the energy transition in order to mitigate the climate change, implies likewise the decr

关键词： drilling technology electro pulse petro-geothermics geoenergy geothermal electricity climate change air pollution.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Comment on "On linking climate to chinese dynastic change:Spatial and temporal variations of monsoonal rain"

引用

chinese Science Bulletin 2010年第32期55卷 3734-3737页

作者： chENG Hai EDWARDS R Lawrence HAUG Gerald H institute of Global Environmental change Xi'an Jiaotong University Xi'an 710049 China department of geology and Geophysics University of Minnesota Minneapolis MN 55455 USA Geological institute Department of Earth Sciences ETH Ziirich CH-8092 Ziirich Switzerland

An article by zhang et al. questions the interpretation of our oxygen isotope record from Wanxiang Cave and the sediment titanium record from Lake Huguang Maar,and the possible linkage between climate change and chinese culture. In response,we explain that their approach lacks logical rigor and their major argument is broadly consistent with,rather than contradictory to our original conclusions. We also note that climate-culture relationships similar to those that we observe in china have been observed for other cultures around the world.

关键词：气候变化时空变化中国雨水季风挂钩氧同位素记录中华文化

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

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

引用

Acta Geologica Sinica(English Edition) 2007年第4期81卷 593-604页

作者： zHOU Rongjun LI Yong Alexander L.DENSMORE Michael A. ELLIS HE Yulin LI Yongzhao LI Xiaogang institute of earthquake Engineering Seismological Bureau of Sichuan Province Chengdu 610041 China National Key Laboratory of Oil and Gas Reservoir geology and Exploitation Chengdu University of Technology Chengdu 610059 China institute of geology Department of Earth Sciences ETH Zentrum CH-8092 Ziirich Switzerland Center for earthquake Research and Information University of Memphis 3890 Central Avenue Memphis TN 38152 USA

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.

关键词： tectonics strike-slip thrusting Late Cenozoic Longmen Shan Tibetan plateau

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Active Tectonics and Erosional Unloading at the Eastern Margin of the Tibetan Plateau

引用

Journal of Mountain Science 2005年第2期2卷 146-154页

作者： Alexander L. Densmore LI Yong Michael A. Ellis zHOU Rongjun institute of geology Department of Earth Sciences ETH Zentrum CH-8092 Zürich Switzerland National Key Laboratory of Oil and Gas Reservoir geology and Exploitation Chengdu University of Technology Chengdu 610059 China Center for earthquake Research and Information University of Memphis 3890 Central Avenue Memphis TN 38152 USA institute of earthquake Engineering Seismological Bureau of Sichuan Province Chengdu 610041 China

The eastern margin of the Tibetan Plateau is marked by an extremely steep mountain front with relief of over 5 km. This topography,coupled with abundant Mesozoic thrusts within the margin,explains why tectonic maps of the India-Asia collision typically show the eastern margin as a major thrust zone. Actually,it does not like that. Field observations suggest that the margin is better characterized as a zone of NNE-directed dextral shear with extensive strike-slip faulting and secondary thrusting. The high relief and steep gradients are partially explained by erosional unloading of an elastic lithosphere;the pre-erosion inherited topography may be the inherited Mesozoic thrust belt landscape modified by a component of Cenozoic tectonic shortening.

关键词： Tibetan Plateau tectonic erosional unloading faulting

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

New constraints on the P-T path of HT/UHT metapelites from the Highland Complex of Sri Lanka

引用

Geoscience Frontiers 2017年第6期8卷 1405-1430页

作者： P.L.Dharmapriya Sanjeewa P.K.Malaviarachchi L.M.Kriegsman Andrea Galli K.Sajeev chengli zhang Postgraduate institute of Science University of Peradeniya20400Sri Lanka department of geology Faculty of ScienceUniversity of Peradeniya20400Sri Lanka Naturalis Biodiversity Center Darwinweg 2NL-2333 CR LeidenThe Netherlands department of earth sciences Utrecht UniversityBudapestlaan 4NL-3584 CD UtrechtThe Netherlands department of earth sciences ETH ZurichSonnegstrasse 5CH-8092 ZurichSwitzerland Centre for earth sciences Indian Institute of ScienceBangalore 560012India Key Laboratory of Continental Dynamics of Northwest University Department of GeologyNorthwest UniversityXi’an 710069China

We report here rare evidence for the early prograde P-Tevolution of garnet-sillimanite-graphite gneiss(khondalite)from the central Highland Complex,Sri *** types of garnet porphyroblasts(Grt_1,Grt_2,Grt_3 and Grt_4)are observed in the rock with specific types of inclusion *** Grt_3 shows evidence for non-coaxial *** the information shows a sequence of main inclusion phases,from old to young:oriented quartz inclusions at core,staurolite and prismatic sillimanite at mantle,kyanite and kyanite pseudomorph,and biotite at rim in Grt_1;fibrolitic sillimanite pseudomorphing kyanite±corundum,kyanite,and spinel+sillimanite after garnet+corundum in Grt_2;biotite,sillimanite,quartz±spinel in Grt_3;and ilmenite,rulite,quartz and sillimanite in Grt_*** pre-melting,original rock composition was calculated through stepwise re-integration of melt into the residual,XRF based composition,allowing the early prograde metamorphic evolution to be deduced from petrographical observations and *** earliest recognizable stage occurred in the sillimanite field at around 575℃ at 4.5 *** collision associated with Gondwana amalgamation led to crustal thickening along a P-T trajectory with an average dP/dT of ~30 bar/℃ in the kyanite field,up to ~660℃ at 6.5 kbar,before crossing the wet-solidus at around 675 ℃ at 7.5 *** highest pressure occurred at P > 10 kbar and T around 780℃ before prograde decompression associated with further *** 825℃ and 10.5 kbar,the rock re-entered into the sillimanite *** temperature peaked at 900℃ at ca.9-9.5 *** near-isobaric cooling led to the growth of Grt_4 and rutile at T ~880℃.Local pyrophyllite rims around sillimanite suggest a late stage of rehydration at Tch probably occurred after uplift to upper crustal levels.U-Pb dating of zircons by LAICPMS of the khondalite yielded two concordant ^(206)Pb/^(238)U age groups with mean values of 542±2 Ma(MSWD=0.24,Th/U=0.01-0.

关键词： Prograde evolution Melt re-integration Highland Complex Sri Lanka UHT granulites

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Distinct metamorphic evolution of alternating silica-saturated and silica-deficient microdomains within garnet in ultrahigh-temperature granulites: An example from Sri Lanka

引用

Geoscience Frontiers 2017年第5期8卷 1115-1133页

作者： P.L.Dharmapriya Sanjeewa P.K.Malaviarachchi Leo M.Kriegsman K.Sajeev Andrea Galli Y.Osanai N.D.Subasinghe C.B.Dissanayake Postgraduate institute of Science University of Peradeniya 20400 Sri Lanka department of geology Faculty of Science University of Peradeniya 20400 Sri Lanka department of geology Naturalis Biodiversity Center Darwinweg 2 2333 CR Leiden The Netherlands department of earth sciences University of Utrecht NL-3584 CD Utrecht The Netherlands Center for earth sciences Indian Institute of Science Bangalore 560012 India department of earth sciences ETH Zurich Sonnegstrasse 5 CH-8092 Zurich Switzerland Division of earth sciences Department of Environmental Changes Faculty of Social and Cultural Studies Kyushu University 744 Motooka Fukuoka 819-0395 Japan National institute of Fundamental Studies Hantana Road Kandy Sri Lanka

Here we report the occurrence of garnet porphyroblasts that have overgrown alternating silica-saturated and silica deficient microdomains via different mineral reactions. The samples were collected from ultrahigh-temperature(UHT) metapelites in the Highland Complex, Sri Lanka. In some of the metapelites, garnet crystals have cores formed via a dehydration reaction, which had taken place at silicasaturated microdomains and mantle to rim areas formed via a dehydration reaction at silica-deficient microdomains. In contrast, some other garnets in the same rock cores had formed via a dehydration reaction which occurred at silica-deficient microdomains while mantle to rim areas formed via a dehydration reaction at silica-saturated microdomains. Based on the textural observations, we conclude that the studied garnets have grown across different effective bulk compositional microdomains during the prograde evolution. These microdomains could represent heterogeneous compositional layers(paleobedding/laminations) in the precursor sediments or differentiated crenulation cleavages that existed during prograde metamorphism. UHT metamorphism associated with strong ductile deformation, metamorphic differentiation and crystallization of locally produced melt may have obliterated the evidence for such microdomains in the matrix. The lack of significant compositional zoning in garnet probably due to self-diffusion during UHT metamorphism had left mineral inclusions as the sole evidence for earlier microdomains with contrasting chemistry.

关键词： UHT Metapelites Garnet Microdomains Highland Complex Sri Lanka

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Magnetostratigraphy and paleoenvironmental record of Tertiary deposits of Lanzhou Basin

引用

chinese Science Bulletin 2001年第9期46卷 770-774页

作者： YUE Leping F.Heller QIU zhanxiang zHANG Li XIE Guangpu QIU zhuding zHANG Yunxiang department of geology Northwest UniversityXi’an 710069China institute of Geophysics ETH-HonggerbergCH-8093 ZurichSwitzerland institute of Vertebrate Paleontology and Paleoanthropology Chinese Academy of SciencesBeijing 100044China Provincial Museum of Gansu Lanzhou 730050China

The Tertiary deposits of the Yongdeng section, the Lanzhou Basin were studied by means of magnetostrati-graphy. The magnetostratigraphic sequences from Paleocene to Miocene were established, and the time scale for the corresponding stratigraphy and mammalian faunas was also established by referring to their correlation to the GPTS of BKSA95 (The geomagnetic polarity time scale which was thoroughly revised and updated by Berggreen et al. in 1995). In the end the paleoenvironmental records and their relationship with the uplifting of the Tibetan Plateau were discussed. The results are as follows. The top boundary of the Xiliugou Formation is dated to be 51 Ma, i.e. Eocene. TheYehucheng Formation covers the time span of 51-31.5 Ma, i.e. from late Early Eocene to early Early Oligocene. The Xianshuihe Formation covers the time span of 31.5-15 Ma, i.e. from Early Oligocene to Middle Miocene. The lower member of the Xianshuihe Formation spans from 31.5 to 20.0 Ma, i.e. from Early Oligocene to early Early

关键词： paleomagnetic stratigraphy Lanzhou Basin Tertiary the Tibetan Plateau paleoenvironment.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：