检索结果-南通市图书馆

Geochemistry and spatial distribution of late-Paleozoic mafic volcanic rocks in the surrounding areas of the Gonghe Basin: Implications for majixueshan triple-junction and east Paleotethyan archipelagic ocean

引用

Science China Earth Sciences 2007年第Z2期50卷 292-304页

作者： GUO AnLin ZHANG GuoWei SUN YanGui CHENG ShunYou YAO AnPing State Key Laboratory of Continental Dynamics Department of Geology Northwest University Xian 710069 China State Key Laboratory of Continental Dynamics Department of Geology Northwest University Xian 710069 China Qinghai Institute of Geological Survey Xining 810012 China State Key Laboratory of Continental Dynamics Department of Geology Northwest University Xian 710069 China State Key Laboratory of Continental Dynamics Department of Geology Northwest University Xian 710069 China

The late-Paleozoic mafic volcanic rocks occurring in the surrounding areas of the Gonghe basin are distributed in the A'nyêmaqên ophiolite zone, Zongwulong tectonic zone and Kuhai-Saishitang volcanic zone. The mafic volcanics in the A'nyêmaqên zone formed an ancient ridge-centered hotspot around the majixueshan OIB, the Kuhai-Saishitang mafic rocks consist of E-MORB and continental rift basalts and the Zongwulong volcanic rocks are enriched N-MORB. The regionally low Nb/U and Ce/Pb ratios reflect the influence of the OIB material on the mafic magma source. From geochemistry, spatial distribution and tectonic relationship of the mafic rocks, an ancient triple-junction centered at the majixueshan can be inferred. The existence of the Kuhai-Saishitang aulacogen may have provided a tectonic channel for the majixueshan OIB materials metasomatizing the magma source for the Zongwulong rocks. The formation of the triple-junction and the rifting of the Zongwulong zone have separated the orogens and massifs in the region.

关键词： OIB, N-MORB, continental rift basalt, majixueshan triple-junction, east Paleotethyan archipelagic ocean

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

Geochemistry and spatial distribution of OIB and MORB in A’nyemaqen ophiolite zone: Evidence of Majixue-shan ancient ridge-centered hotspot

引用

Science China Earth Sciences 2007年第2期50卷 197-208页

作者： GUO AnLin ZHANG GuoWei SUN YanGui ZHENG JianKang LIU Ye WANG JianQi National Key Lab of Continental Dynamics Northwest UniversityXi’an 710069China Qinghai Institute of Geological Survey Xining 810012China

The mafic volcanic association is made up of OIB, E-MORB and N-MORB in the A'nyemaqen Paleozoic ophiolites. Compared with the same type rocks in the world, the mafic rocks generally display lower Nb/U and Ce/Pb ratios and some have Nb depletion and Pb enrichment. The OIB are LREE-enriched with (La/Yb)N =5―20, N-MORB are LREE-depleted with (La/Yb)N = 0.41―0.5. The OIB are featured by incompatible element enrichment and the N-MORB are obviously depleted with some metasomatic ef- fect, and E-MORB are geochemically intermediated. These rocks are distributed around the Majixue- shan OIB and gabbros in a thickness greater than a thousand meters and transitionally change along the ophiolite extension in a west-east direction, showing a symmetric distribution pattern as centered by the majixueshan OIB, that is, from N-MORB, OIB and E-MORB association in the Dur'ngoi area to OIB in the majixueshan area and then to N-MORB, OIB and E-MORB assemblage again in the Buqing- shan area. By consideration of the rock association, the rock spatial distribution and the thickness of the mafic rocks in the majixueshan, coupled with the metasomatic relationship between the OIB and MORB sources, it can be argued that the majixueshan probably corresponds to an ancient hotspot or an ocean island formed by mantle plume on the A'nyemaqeh ocean ridge, that is the ridge-centered hotspot, tectonically similar to the present-day Iceland hotspot.

关键词： A’nyemaqen ophiolite zone OIB N-MORB and E-MORB association spatial distribution majixueshan ridge-centered hotspot me- tasomatism mantle plume

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

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

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：