Facies analysis of the Mapepe Foreland Basin, Barberton Greenstone Belt, by well-to-well correlation

太古代生物地球化学循环知之甚少，但对于理解我们这个星球--S生态圈的演化至关重要。揭示太古代海洋的组成及其与大气和生物圈相互作用的关键部分之一位于南非巴伯顿绿岩带(BGB)的中太古代(约3250 Ma)无花果树群。这一部分的很大一部分是最近在ICDP支持的钻探项目中取心的。岩心剖面Barb-5包括细粒到粗粒的沉积物和火山碎屑；铁质、碳质和硅质化学沉积物；以及撞击球层。它们都沉积在一个向上加深的扇三角洲-铁质深海盆地中。附近的地质填图显示出很高的相变异性。核心材料在地球化学方面具有吸引力，提交的14份提案证明了这一点。然而，成功的样品分析和解释将取决于详细的沉积学解释，这需要从核心到表面的一体化。拟议的项目将把763m岩心与地表剖面、区域趋势以及最终在附近钻探的与年龄相当的BIF剖面的BARB-4岩芯联系起来。结果将限制两口井的地球化学指标的解释，并有助于了解生物化学以及盆地内外对岩性和岩相的控制。申请的资金包括旅费、有限的实地工作和分析费用。

Archaean biogeochemical cycles are poorly understood yet critical to comprehend the evolution of our planet-s ecosphere. One of the key sections shedding light on the composition of the Archaean ocean and its interaction with the atmo- and biosphere lies in the Middle Archaean (ca. 3250 Ma old) Fig Tree Group, Barberton Greenstone Belt (BGB), South Africa. A substantial part of this section was recently cored in an ICDP-supported drilling project. The cored section, BARB-5, includes fine- to coarse-grained sediments and volcaniclastics; ferruginous, carbonaceous, and cherty chemical sediments; and an impact spherule bed. They were all deposited in a deepening-upward, fan-delta to ferruginous deep-marine basin. Geological mapping in the vicinity indicates a high facies variability. The core material is geochemically attractive, evidenced by 14 submitted proposals. Successful sample analysis and interpretation, however, will depend on a detailed sedimentological interpretation, requiring core-to-surface integration. The proposed project will correlate the 763 m-core with surface sections, regional trends and eventually the BARB-4 core which drilled an age-equivalent BIF section nearby. Results will constrain the interpretation of geochemical proxies from both wells and contribute to the understanding of biochemical and extra- and intrabasinals controls on lithologies and facies. Funds applied for include travel money, limited field work, and analytical expenses.