[Reimold] Spherule layers in the 2011 ICDP drilling in the Barberton Mountain Land: Early impact record on Earth

German Title: Spherule layers in the 2011 ICDP drilling in the Barberton Mountain Land: Early impact record on Earth

Abbreviation: 317

Current Status: completed with report

Main Applicant:Prof. Dr. Uwe Reimold

Resources Recipient

Other Persons

Dr. Jörg Peter Fritz

Conveyor Begin:
Conveyor End:
Conveyor Duration:
Year: 2013


The 2011 ICDP drilling “Barberton Mountain Land” drilled relatively unweathered rare late Archean volcanic and sedimentary rocks including the oldest known impact ejecta layers on Earth. The chemical signature (high Iridium concentrations, Chromium isotopic ratios) of some of these up to tens of cm thick Archean spherule layers advocate that these ejecta deposits formed dominantly from extraterrestrial material. The ejecta layers contain millimeter sized spherules that are larger and form thicker layers compared to any impact ejecta layer known from Phanerozoic sediments, including the global ejecta layer of the Chicxulub impact catering event that terminated the Mesozoic era of Earth’s history. We propose to conduct 1) bulk chemical analyses of major and trace elements, 2) petrographic, micro-chemical and mineralogical characterization of the impact ejecta layers, and 3) LA-ICP-MS elemental mapping of platinum group element (PGE) distributions. This aims at 1) characterization of the ejecta layers, 2) identification of the phases hosting the extraterrestrial PGE signature, 3) discrimination of the primary geological evidence of the impact event from those characteristics that resulted from syn- and post-sedimentary alteration. We want to exploit the geological evidence for extracting key information regarding size, type and frequency of projectiles impacting the Archean Earth.

Related Publications

Mohr-Westheide, T., Greshake, A., Wirth, R., Reimold, W. U. (2018). "Transmission electron microscopy of impact-generated platinum group element alloys from Barberton spherule layers: New clues to their formation" Meteoritics & Planetary Science 53 p1516-1536

Fritz, Jörg, Tagle, Roald, Ashworth, Luisa, Schmitt, Ralf Thomas, Hofmann, Axel, Luais, Béatrice, Harris, Phillip D., Hoehnel, Desirée, Özdemir, Seda, Mohr‐Westheide, Tanja, Koeberl, Christian (2016). "Nondestructive spectroscopic and petrochemical investigations of Paleoarchean spherule layers from the ICDP drill core BARB5, Barberton Mountain Land, South Africa" Meteoritics & Planetary Science 51 p2441-2458

Mohr-Westheide, Tanja, Reimold, Wolf U, Fritz, Jörg, Koeberl, Christian, Salge, Tobias, Hofmann, Axel, Schmitt, Ralf T (2015). "Discovery of extraterrestrial component carrier phases in Archean spherule layers: Implications for estimation of Archean bolide sizes" Geology 43 p299-302

Koeberl, Christian, Schulz, Toni, Reimold, W. Uwe (2015). "Remnants of Early Archean Impact Deposits on Earth: Search for a Meteoritic Component in the BARB5 and CT3 Drill Cores (Barberton Greenstone Belt, South Africa)" Procedia Engineering 103 p310-317