Folding within seconds

Research Article| March 01, 2002 Folding within seconds Thomas Kenkmann Thomas Kenkmann 1Institut für Mineralogie, Museum für Naturkunde, Humboldt-Universität Berlin, D-10115 Berlin, Germany Search for other works by this author on: GSW Google Scholar Author and Article Information Thomas Kenkmann 1Institut für Mineralogie, Museum für Naturkunde, Humboldt-Universität Berlin, D-10115 Berlin, Germany Publisher: Geological Society of America Received: 02 Jul 2001 Revision Received: 22 Oct 2001 Accepted: 26 Nov 2001 First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (2002) 30 (3): 231–234. https://doi.org/10.1130/0091-7613(2002)030<0231:FWS>2.0.CO;2 Article history Received: 02 Jul 2001 Revision Received: 22 Oct 2001 Accepted: 26 Nov 2001 First Online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Thomas Kenkmann; Folding within seconds. Geology 2002;; 30 (3): 231–234. doi: https://doi.org/10.1130/0091-7613(2002)030<0231:FWS>2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Hypervelocity impacts of cosmic projectiles larger than ∼200 m diameter are capable of forming complex craters on Earth. At these craters, shock loading, shock damage, and excavation flow are followed by a gravity-driven collapse of the deep transient cavity. Such impact structures are characterized by a central uplift, a flat crater floor, and a terraced crater rim. Collapse-induced deformation features, like folds and brittle fault zones, have many similarities to tectonic structures. Typical deformation patterns of complex terrestrial impact craters of 5–15 km diameter are compiled and analyzed with respect to their kinematic development. Unlike their tectonic counterparts, deformation structures are always the result of non-plane-strain deformation and are formed in a single event that takes place in seconds to minutes. To understand the high-strain-rate processes, the microstructure of an impact-induced fold of the Crooked Creek impact crater (∼7 km diameter), Missouri, United States, is investigated in detail. A period of 20–30 s at the most is determined for the collapse phase of this crater. The gross plastic deformation behavior of the fold is achieved by localized brittle deformation along millimeter- to centimeter-spaced fault zones, forming a network of veins. Shock damage has fractured ∼40% of grain boundaries. The onset of collapse and associated deformation started in rocks with a reduced cohesion and is friction controlled. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.