• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>South African Journal of Geology: Being the Transaction of the Geological Society of South African: Syndie die Verhandelinge van die Geologiese Vereniging van Suid-Afrika >Volcanological and petrogenetic characteristics of komatiites of the 3.3 Ga Saw Mill Complex, Weltevreden Formation, Barberton Greenstone Belt, South Africa
【24h】

Volcanological and petrogenetic characteristics of komatiites of the 3.3 Ga Saw Mill Complex, Weltevreden Formation, Barberton Greenstone Belt, South Africa

机译：3.3 GA锯磨机，Weltevreden Clower，Barberton Greenstone Belt，南非的Plcanolocticatiens的波动性特征

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The Saw Mill Complex (SMC) is a 1 275 m thick layered komatiitic sequence in the 3.3 Ga Weltevreden Formation, uppermost stratigraphic unit of the Onverwacht Group in the northern part of the Barberton Greenstone Belt, South Africa. A series of ultramafic complexes in the Weltevreden Formation have previously been interpreted as layered ultramafic intrusions, consisting of thick, layered ultramafic units of peridotite, pyroxenite, dunite, and gabbro. However, recent work on the Pioneer complex of the Weltevreden Formation has demonstrated an extrusive origin of komatiitic flows and tuffs. The Weltevreden Formation has not been studied in the detail of other Onverwacht Group units, but it is likely composed of a number of individual tectonically juxtaposed terrains brought in by thrust faulting during deposition of Fig Tree Group sediments and felsic volcanics in a magmatic arc setting post-dating the Onverwacht mafic and ultramafic units, which are currently regarded as products of plume-based eruptive centers. This study represents an ongoing effort to elucidate the structure, stratigraphy, and petrogenesis of the Weltevreden Formation. A new 1:1000 scale map and stratigraphic section of the SMC reinterpret the igneous complex as extrusive, with lithologic units interpreted as layered komatiitic flows and interbedded tuffs. Flows accumulated olivine, forming distinct layers from bottom to top of: olivine adcumulate (dunitic lithologies), ·poikilitic orthopyroxene with abundant olivine inclusions (pyroxenitic lithologies), and ·olivine orthocumulate (peridotitic lithologies), and sometimes with a cap of ·olivine-depleted pyroxene-rich orthocumulates (komatiitic basalts).
机译：锯磨机（SMC）是3.3 Ga Weltevreden的形成，南非北部的北部地区的3.3 Ga Weltevreden的综合组织中的175米厚的分层柯马蒂蒂氏序列。 WelteTevreden的形成中的一系列超空白复合物以前被解释为层状uteramfiC入侵，包括厚度，分层紫外线单位，Pyroxenite，Dunite和Gabbro。然而，最近对WelteTevreden形成的先驱复合物的工作已经表现出一种巨大的柯马蒂蒂氏流量和凝灰岩的兴奋。 WelteTevreden的形成尚未在其他Onverwacht集团单位的细节中进行研究，但它可能由许多通过推力断裂沉积在无花果树组沉积物和岩石弧形设置柱中的肠球火山中引起的各个单明并置地表组成 - 当目前被认为是羽毛的喷发中心产品的onverwacht MAFIC和Ultramafic单位。本研究代表了持续努力阐明威尔特雷维德形成的结构，地层和纤维化。一个新的1：1000尺度图和SMC的地图和地层部分重新诠释了Igneous Complex作为Extuse，其中岩性单元被解释为分层柯马蒂蒂氏流量和互夹具的牙龈。流动累积的橄榄石，形成从底部到顶部的明显层：橄榄石和卵石岩状物质），·波西蒂氏岩性卵黄烯烃，具有丰富的橄榄石夹杂物（Pyroxenitic Lithologies），以及橄榄石正梗塞（橄榄石岩性），有时液体溶液 - 富含富己的正交（Komatiitic BaSalts）。

著录项

相似文献

  • 外文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号