Ophiolite hosted chromitite formed by supra-subduction zone peridotite–plume interaction

来源 :地学前缘(英文版) | 被引量 : 0次 | 上传用户:pp
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
Chromitite bodies hosted in peridotites typical of suboceanic mantle (s.l. ophiolitic) are found in the northern and central part of the Loma Caribe peridotite, in the Cordillera Central of the Dominican Republic. These chromitites are massive pods of small size (less than a few meters across) and veins that intrude both dunite and harzburgite. Compositionally, they are high-Cr chromitites [Cr#=Cr/(Cr+Al) atomic ratio=0.71–0.83] singularly enriched in TiO2 (up to 1.25 wt.%), Fe2O3 (2.77–9.16 wt.%) as well as some trace elements (Ga, V, Co, Mn, and Zn) and PGE (up to 4548 ppb in whole-rock). This geochemical signature is unknown for chromitites hosted in oceanic upper mantle but akin to those chromites crystallized from mantle plume derived melts. Noteworthy, the melt estimated to be in equilibrium with such chromite from the Loma Caribe chromitites is similar to basalts derived from different source regions of a heterogeneous Caribbean mantle plume. This mantle plume is responsible for the formation of the Caribbean Large Igneous Province (CLIP). Dolerite dykes with back-arc basin basalt (BABB) and enriched mid-ocean ridge basalt (E-MORB) affinities commonly intrude the Loma Caribe peridotite, and are interpreted as evidence of the impact that the Caribbean plume had in the off-axis magmatism of the back-arc basin, developed after the Caribbean island-arc extension in the Late Cretaceous. We propose a model in which chromitites were formed in the shallow portion of the back-arc mantle as a result of the metasomatic reaction between the supra-subduction zone (SSZ) peridotites and upwelling plume-related melts.
其他文献
摘要:戏剧文学体裁的文章,对初中学生来说是很陌生、很新奇的。因为它本身的特殊性也就给我们一线教师的教学带来了挑战。怎样让学生感受到戏剧的魅力?怎样理解人物之间的矛盾冲突?怎样解读人物的性格?笔者就自己教学的感受谈点认识和思考。关键词:戏剧;矛盾冲突;舞台说明;人物形象    戏剧艺术,是文学艺术宝库中的瑰宝,它种类繁多,各具特色。苏教版的语文教材在九年级下册中第一单元就收录了具有代表性的《威尼斯商
四川省住房和城乡建设厅日前出台了《芦山地震灾区城镇安居住房建设管理指导意见》(以下简称《意见》),并向芦山地震灾区有关市(州)、县(市、区)住房城乡建设行政主管部门发
This study provides characteristics of aerosol columnar properties, measured over ten countries in Eastern Europe from 2002 to 2019. Aerosol optical depth (AOD)
The giant Central Asian Orogenic Belt is an extensive accretionary orogen, of which the Solonker suture, as a major regional suture, coincides closely with an e
谷歌的模块化智能手机项目还处于早期阶段,但是一些开发者和狂热爱好者已经开始构思如何打造可置组件了。在远处一看,加勒特?金斯曼掌中的这台设备就像是谷歌Project Ara项目
请下载后查看,本文暂不支持在线获取查看简介。 Please download to view, this article does not support online access to view profile.
在摸索中前进大兴县地处北京市东南郊,水稻面积曾发展到30多万亩,成为北京市水稻主要产区。但由于北京地区及永定河上游,年际间降水量极不平衡,故生产很不稳定,1972年由于受
In this contribution we present new insights on the evolution of the Dom Feliciano Belt, southernmost Man-tiqueira Province, integrating new whole-rock Sm–Nd i
该系统适用于对各种规格品种泵进行全性能试验,运行性能稳定可靠。具有人机界面图形功能及微机中强大软件支持功能,采用新型传感检测各参数变量,计算机巡回采集原始数据,数据实时
Quantification of a mineral prospectivity mapping (MPM) heavily relies on geological, geophysical and geochemical analysis, which combines various evidence laye