检索结果-南通市图书馆

Was the Panzhihua Large Fe-Ti Oxide Deposit,SW China,Formed by Silicate Immiscibility?

地质学报:英文版 2023年第5期97卷 1451-1461页

作者： DING Xiangli CHEN Xuanhua SHAO Zhaogang Chinese Academy of Geological Sciences Beijing 100037China

The Panzhihua mafic intrusion,which hosts a world-class Fe-Ti-V ore deposit,is in the western Emeishan region,SW *** formation age(~260 Ma),and Sr and Nd isotopes indicate that the Panzhihua intrusion is part of the Emeishan large igneous province and has little crustal *** assess ore genesis of the Panzhihua Fe-Ti-V ore deposit,two different models have been provided to explain the formation,namely silicate immiscibility and normal fractional *** immiscibility occurring around 1,000℃at the late stage of basaltic magma evolution argues against the silicate immiscibility ***-hosted melt inclusion research indicates that silicate immiscibility occurred at the late stage of Panzhihua magma evolution,which may not have offered potential to form such large ore deposits as ***,continuous compositional variations of the Panzhihua intrusion and calculations using thermodynamic modelling software support the hypothesis that the Panzhihua deposit was formed by normal fractional *** trace element patterns of the Panzhihua intrusion and nearby felsic rocks also coincide with the fractional crystallization *** fractional crystallization of high-Ti basaltic magma played a key role in the formation of the Panzhihua Fe-Ti-V ore deposit.

关键词： liquid immiscibility fractional crystallization mafic intrusion Fe-Ti oxide deposit Panzhihua

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

Geochronologic Constraints on the Magmatic Underplating of the Gangdisê Belt in the India-Eurasia Collision: Evidence of SHRIMP II Zircon U-Pb Dating

引用

Acta Geologica Sinica(English Edition) 2005年第6期79卷 787-794页

作者： DONG Guochen MO Xuanxue ZHAO Zhidan GUO Tieying WANG Liangliang CHEN Tao State Key Laboratory of Geological Processes and Mineral Resources China University of Geosciences Beijing 100083 School of Earth Science and Resources China University of Geosciences Beijing 100083 Hebei B.rea. of Geology and Mineral Exploration and Development Shijiazhuang Hebei 050081

Abundant small mafic intrusions occur associated with granitoids along the Gangdise^ magmatic belt. In addition to many discrete gabbro bodies within the granitoid plutons, a gabbro-pyroxenite zone occurs along the southern margin of the Gangdise^ belt to the north of the Yarlung Zangbo suture. The mafic intrusion zone spatially corresponds to a strong aeromagnetic anomaly, which extends -1400 km. The mafic intrusions consist of intermittently distributed small bodies and dikes of gabbro and dolerite with accumulates of pyroxenite, olivine pyroxenite, pegmatitic pyroxenite and amphibolite. Much evidence indicates that the Gangdise^ gabbro-pyroxenite assemblage is most likely a result of underplating of mantle-derived magma. Detailed field investigation and systematic sampling of the mafic rocks was conducted at six locations along the Lhasa-Xigaze^ segment of the mafic intrusive zone, and was followed by zircon SHRIMP Ⅱ U-Pb dating. In addition to the ages of two samples previously published （47.0±1 Ma and 48.9±1.1 Ma）, the isotopic ages of the remaining four gabbro samples are 51.6±1.3Ma, 52.5±3.0 Ma, 50.2±4.2Ma and 49.9±1.1Ma. The range of these ages （47-52.5 Ma） provide geochronologic constraints on the Eocene timing of magma underplating beneath the Gangdise^ belt at ca. 50 Ma. This underplating event post-dated the initiation of the India-Eurasia continental collision by 15 million years and was contemporaneous with a process of magma mixing. The SHRIMP Ⅱ U-Pb isotopic analysis also found several old ages from a few zircon grains, mostly in a range of 479-526 Ma （weighted average age 503±10 Ma）, thus yielding information about the pre-existing lower crust when underplating of mafic magma took place. It is believed that magma underplating was one of the major mechanisms for crustal growth during the Indian-Eurasia collision, possibly corresponding in time to the formation of the 14-16 km-thick ＂crnst-mantle transitional zone＂ characterized by Vp=6.85-6.9 km/s.

关键词： SHRIMP U-Pb dating mafic intrusion gabbro underplating the Gangdise^ Tibet

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：