Nondestructive spectroscopic and petrochemical investigations of Paleoarchean spherule layers from the ICDP drill core BARB5, Barberton Mountain Land, South Africa
Nondestructive spectroscopic and petrochemical investigations of Paleoarchean spherule layers from the ICDP drill core BARB5, Barberton Mountain Land, South Africa
复制标题
对来自南非巴伯顿山地 ICDP 钻芯 BARB5 的古太古代小球层进行无损光谱和石油化学研究
DOI：
10.1111/maps.12736
复制
发表时间：
2016
影响因子：
2.2
通讯作者：
Koeberl
中科院分区：
文献类型：
--
作者：
Ashowrth;Schmitt;Hofmann;Harris;Hoehnel;Oezdemir;Mohr-Westheide;Koeberl
采用无损分析技术对南非巴伯顿山地无花果树群下Mapepe组763 m长的国际大陆科学钻探计划（ICDP）钻芯BARB 5的古太古代撞击球粒含层段进行了研究。给出了岩心的目视观察、红外（IR）光谱成像和微X射线荧光（μXRF）结果。岩相学和沉积特征，以及从微米到千米尺度的岩性的主要和微量元素成分，有助于定位和表征512.6米和510.5米深度之间的8个含球粒间隔。球粒层出现在517和503米之间的强烈变形段，在上面和下面的核心的岩石显然是少扰动。μXRF元素图显示，球粒层具有相似的岩相学和地球化学特征，但在（1）两种球粒的分选和（2）原生矿物（镍铬尖晶石和锆石）的产状方面存在差异。我们倾向于一个单一的影响场景，其次是冲击后的返工，以及随后的改变。球粒层富含Al 2 O3，可以通过电磁波谱短波红外（SWIR）区域中明显的Al-OH吸收特征与贫Al 2 O3的海洋沉积物区分开来。红外图像可以覆盖数十至数百平方米的岩性，因此可以用于在贫Al 2 O3沉积物中寻找富含Al-OH的球粒层，例如始新世变质沉积物，其中球粒层的结构特征被变质作用掩盖。
A Paleoarchean impact spherule‐bearing interval of the 763 m long International Continental Scientific Drilling Program (ICDP) drill core BARB5 from the lower Mapepe Formation of the Fig Tree Group, Barberton Mountain Land (South Africa) was investigated using nondestructive analytical techniques. The results of visual observation, infrared (IR) spectroscopic imaging, and micro‐X‐ray fluorescence (μXRF) of drill cores are presented. Petrographic and sedimentary features, as well as major and trace element compositions of lithologies from the micrometer to kilometer‐scale, assisted in the localization and characterization of eight spherule‐bearing intervals between 512.6 and 510.5 m depth. The spherule layers occur in a strongly deformed section between 517 and 503 m, and the rocks in the core above and below are clearly less disturbed. The μXRF element maps show that spherule layers have similar petrographic and geochemical characteristics but differences in (1) sorting of two types of spherules and (2) occurrence of primary minerals (Ni‐Cr spinel and zircon). We favor a single impact scenario followed by postimpact reworking, and subsequent alteration. The spherule layers are Al2O3‐rich and can be distinguished from the Al2O3‐poor marine sediments by distinct Al‐OH absorption features in the short wave infrared (SWIR) region of the electromagnetic spectrum. Infrared images can cover tens to hundreds of square meters of lithologies and, thus, may be used to search for Al‐OH‐rich spherule layers in Al2O3‐poor sediments, such as Eoarchean metasediments, where the textural characteristics of the spherule layers are obscured by metamorphism.
登录
查看更多内容
在太古代小球层中发现外星成分载波相位：对估计太古代火流星尺寸的影响
影响因子：
5.8
作者：
Mohr-Westheide;Reimold;Koeberl;Hofmann;Schmitt
通讯作者：
Schmitt
南非巴伯顿绿岩带 3.24 Ga 撞击球粒中富镍铬尖晶石存在低 O2 太古宙大气的证据
DOI：
--
发表时间：
2010
期刊：
影响因子：
--
作者：
A. E. Krull;G. Byerly;D. Lowe
通讯作者：
D. Lowe
南非巴伯顿山区早期太古代花岗岩-绿岩演化的年代学，基于单锆石蒸发的精确测年。
影响因子：
5.3
作者：
A. Krüner;G. Byerly;D. Lowe
通讯作者：
D. Lowe
窥视生命的摇篮：南非巴伯顿绿岩带的科学钻探
DOI：
--
发表时间：
2012
期刊：
影响因子：
--
作者：
N. Arndt;Barberton Drilling Team
通讯作者：
Barberton Drilling Team
影响因子：
3.1
作者：
E. Duke;Reed S. Lewis
通讯作者：
E. Duke;Reed S. Lewis