Active faulting and folding without topographic expression in an evaporite basin, Chile

Research Article| November 01, 2002 Active faulting and folding without topographic expression in an evaporite basin, Chile T.E. Jordan; T.E. Jordan 1Department of Earth and Atmospheric Sciences, Cornell University, Ithaca, New York 14853-1504, USA Search for other works by this author on: GSW Google Scholar N. Muñoz; N. Muñoz 2SIPETROL (UK) Ltd., St. Andrew's House, Woking Surrey GU21 1EB, UK Search for other works by this author on: GSW Google Scholar M. Hein; M. Hein 3Department of Geological Sciences and Environmental Studies, Binghamton University, Binghamton, New York 13902, USA Search for other works by this author on: GSW Google Scholar T. Lowenstein; T. Lowenstein 3Department of Geological Sciences and Environmental Studies, Binghamton University, Binghamton, New York 13902, USA Search for other works by this author on: GSW Google Scholar L. Godfrey; L. Godfrey 4Department of Earth and Atmospheric Sciences, Cornell University, Ithaca, New York 14853-1504, USA Search for other works by this author on: GSW Google Scholar J. Yu J. Yu 4Department of Earth and Atmospheric Sciences, Cornell University, Ithaca, New York 14853-1504, USA Search for other works by this author on: GSW Google Scholar Author and Article Information T.E. Jordan 1Department of Earth and Atmospheric Sciences, Cornell University, Ithaca, New York 14853-1504, USA N. Muñoz 2SIPETROL (UK) Ltd., St. Andrew's House, Woking Surrey GU21 1EB, UK M. Hein 3Department of Geological Sciences and Environmental Studies, Binghamton University, Binghamton, New York 13902, USA T. Lowenstein 3Department of Geological Sciences and Environmental Studies, Binghamton University, Binghamton, New York 13902, USA L. Godfrey 4Department of Earth and Atmospheric Sciences, Cornell University, Ithaca, New York 14853-1504, USA J. Yu 4Department of Earth and Atmospheric Sciences, Cornell University, Ithaca, New York 14853-1504, USA Publisher: Geological Society of America Revision Received: 23 Apr 2001 Received: 20 Jul 2001 Accepted: 09 May 2002 First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (2002) 114 (11): 1406–1421. https://doi.org/10.1130/0016-7606(2002)114<1406:AFAFWT>2.0.CO;2 Article history Revision Received: 23 Apr 2001 Received: 20 Jul 2001 Accepted: 09 May 2002 First Online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation T.E. Jordan, N. Muñoz, M. Hein, T. Lowenstein, L. Godfrey, J. Yu; Active faulting and folding without topographic expression in an evaporite basin, Chile. GSA Bulletin 2002;; 114 (11): 1406–1421. doi: https://doi.org/10.1130/0016-7606(2002)114<1406:AFAFWT>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 SocietyGSA Bulletin Search Advanced Search Abstract The Salar de Atacama in northern Chile accumulated halite during the Pliocene and Quaternary under conditions that alternated between a saline lake and a dry salt flat. Hidden beneath its uninterrupted flat surface is the Salar fault system. The halite deposits provide a high-resolution history of deformation. Contours on the ca. 5 Ma base of the halite unit in the southern salar, defined in a deep oil-exploration borehole and traced through reflection seismic lines, reveal that net reverse offset across the Salar fault system is down-to-the-east by ∼900 m; of that total, 200 m occurred during the Quaternary and 700 m during the Pliocene. Distributions, thicknesses, and geometries of eight stratigraphic sequences within the halite unit reveal a history of episodic faulting and demonstrate that faulting during approximately half the 5 m.y. interval, including the Holocene, did not generate fault scarps. We suggest that deposition caused by evaporation of ground water brines in the salt flat, rather than either dissolution or deflation, has smoothed the topography of the dry lake bed across the active fault zone. For the case of west-directed groundwater flow, we propose that the east-facing Salar fault system focuses groundwater flux along the eastern flank of the fault, which enhances halite precipitation in the downthrown block during desiccated stages and counteracts fault-driven topographic relief. The realization that a seismic risk may exist even though the Salar fault system is hidden leads to the appreciation that similar unrecognized seismic risks may exist in more populous arid basins. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.