检索结果-南通市图书馆

Conditioned duality between supercontinental’assembly’and’breakup’LIPs

Geoscience Frontiers 2020年第5期11卷 1635-1649页

作者： Martin B.Klausen Department of Earth Sciences Stellenbosch UniversityPrivate Bag X1MatielandSouth Africa

A compilation of 178 more precise ages on 10 potential Large Igneous Provinces(LIPs)across southern Africa,is compared to Earth’s supercontinental cycles,where 5 more prominent LIP-events all formed during the assembly of supercontinents,rather than during *** temporal bias is confirmed by a focused review of field relationships,where these syn-assembly LIPs formed behind active continental arcs;whereas,the remaining postassembly-and likely breakup-related-LIPs never share such *** the possibility of two radically different LIP-types,only the two younger breakup events(the Karoo LIP and Gannakouriep Suite)produced basalts with more enriched asthenospheric OIB-signatures;whereas,all assembly LIPs produced basalts with stronger lithospheric,as well as more or less primitive asthenospheric,signatures.A counterintuitive observation of Precambrian breakup LIPs outcropping as smaller fragments that are more peripherally located along craton margins,compared to assembly LIPs as well as the Phanerozoic Karoo breakup LIP,is explained by different preservation potentials during subsequent supercontinental ***,further accentuating radical differences between(1)breakup LIPs,preferentially intruding along what evolves to become volcanic rifted margins that are more susceptible to deformation within subsequent orogens,and(2)assembly LIPs,typically emplaced along backarc rifts within more protected cratonic interiors.A conditioned duality is proposed,where assembly LIPs are primarily sustained by thermal blanketing(as well as local arc hydration and rifting)below assembling supercontinents and breakup LIPs more typically form above impinging mantle *** a duality is further related to an overall dynamic Earth model whereby predominantly supercontinent-orientated ocean lithospheric subduction establishes/revitalizes large low shear velocity provinces(LLSVPs)during assembly LIP-activity,and heating of such LLSVPs by the Earth’s core subsequ

关键词： Large igneous provinces Extrovert plate tectonics LLSVP Mantle dynamics geochemical discrimination

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

Implications of REE incorporation and host sediment influence on the origin and growth processes of ferromanganese nodules from Central Indian Ocean Basin

引用

Geoscience Frontiers 2021年第3期12卷 609-623页

作者： Simontini Sensarma Abhishek Saha Arghya Hazra CSIR-National Institute of Oceanography Dona PaulaGoa 403004India Indian Institute of Science BangaloreKarnataka 560012India School of Earth Ocean and Atmospheric SciencesGoa UniversityGoa 403206India

This study presents new major,trace and REE data for thirty-five ferromanganese nodules recovered from areas representing three different sediment types(siliceous,red clay and their transition zone)in the Central Indian Ocean Basin(CIOB)to address their genetic aspects,classification,growth rate,nature of host sediments and influence of REE in the processes of nodule *** nodules from CIOB are mostly either hydrogenetic(metals coming from oxygenated bottom water)and diagenetic(metals coming from suboxic sediment pore water)or a combination of both,depending on the source of supply of ***,a number of biogeochemical processes mediate this supply of metals which again changes from time to time,making the nodule growth process highly *** study suggests that at the initial stage of nodule growth,host sediments do not play much role in controlling the growth processes for which REEs can enter both Mn and Fe oxyhydroxide phases ***,the bottom water signature is imprinted in these early formed nodules irrespective of their host sediment substrate but with gradual growth and burial in the sediment,the main mode of metal enrichment becomes diagenetic through sediment pore *** tends to increase the concentration of Mn,Ni and Cu over other elements which are retained in the sediment *** the REEs,Ce concentration of the nodules shows significant positive anomaly due to variation in redox potential and hence its magnitude can be used to get an idea about the metal enrichment procedure and the genetic type of the ***,based on host sediment only,not much difference is found in the magnitude of Ce anomaly in these *** the other hand,discrimination diagram,based on HFSE and REY chemistry,indicates that most of these nodules are of diagenetic origin under oxic condition with a trend towards hydrogenetic ***,the genetic type of the ferromanganese nodules from the CIOB are more effectively differentiated

关键词： Central Indian Ocean Basin Ferromanganese nodules Deep-sea sediments Rare earth elements geochemical discrimination

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

Tectonic discrimination of olivine in basalt using data mining techniques based on major elements:a comparative study from multiple perspectives

引用

Big Earth Data 2019年第1期3卷 8-25页

作者： Qiubing Ren Mingchao Li Shuai Han State Key Laboratory of Hydraulic Engineering Simulation and Safety Tianjin UniversityTianjinChina

The olivine in basalt records much information about formation and evolution of basaltic magma,which may help to discriminate basalt tectonic ***,the viewpoint that olivine is connected with the tectonic setting where it formed is *** verify the hypothesis,we intend to discriminate the basalt tectonic settings by geochemical characteristics of *** data mining technique is selected as an effective tool for this study,which is a new attempt in geochemical *** geochemical data of olivine used is extracted from open-access and comprehensive petrological *** classification performance of Logistic regression classifier,Naïve Bayes,Random Forest and Multi-layer perception(MLP)algorithms is firstly compared under some *** results of the basic experiment indicate that MLP has the highest classification accuracy of about 88%based on raw data,followed by Random *** this does not fully prove the hypothesis is ***,the crossvalidation method and other measurement criteria are integrated for scientific and in-depth comparative *** advanced experiments mainly include the comparison of different data preprocessing methods,combinations of geochemical characteristics and sample data *** turns out that chemical composition of olivine in basalt has the function of discriminating tectonic settings.

关键词： Olivine in basalt tectonic setting geochemical discrimination data mining comparative study

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

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

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

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：