Stratigraphic response to saline lake-level fluctuations and the origin of cyclic nonmarine evaporite deposits: The Pleistocene Blanca Lila Formation, northwest Argentina

Abstract

Research Article| February 01, 1997 Stratigraphic response to saline lake-level fluctuations and the origin of cyclic nonmarine evaporite deposits: The Pleistocene Blanca Lila Formation, northwest Argentina Dirk S. Vandervoort Dirk S. Vandervoort 1Institute for the Study of the Continents and Department of Geological Sciences, Cornell University, Ithaca, New York 14853 Search for other works by this author on: GSW Google Scholar Author and Article Information Dirk S. Vandervoort 1Institute for the Study of the Continents and Department of Geological Sciences, Cornell University, Ithaca, New York 14853 Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1997) 109 (2): 210–224. https://doi.org/10.1130/0016-7606(1997)109<0210:SRTSLL>2.3.CO;2 Article history First Online: 01 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 Dirk S. Vandervoort; Stratigraphic response to saline lake-level fluctuations and the origin of cyclic nonmarine evaporite deposits: The Pleistocene Blanca Lila Formation, northwest Argentina. GSA Bulletin 1997;; 109 (2): 210–224. doi: https://doi.org/10.1130/0016-7606(1997)109<0210:SRTSLL>2.3.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 Stratigraphic analysis of Pleistocene nonmarine bedded evaporites in northwest Argentina elucidates the effect that episodic saline lake expansion and contraction have on the stratigraphic completeness of units deposited and preserved in a continental saline environment. Stratigraphic successions in these rocks contain features that relate uniquely to fluctuations in saline lake level. Bounding the top of each succession is a surface with evidence for an abrupt increase in water depth. Because sediment accumulation and stratal preservation vary spatially as a function of lake level, the degree of stratigraphic completeness varies among locations. These results have implications for attempts to extract the record of continental climate change from saline lake strata.Bedded evaporites in these strata accumulated in a saline lake characterized by a marginal zone of gypsum and ulexite with clastic interbeds and an accumulation of halite in the saline lake center. Four internally conformable successions of genetically related lithofacies assemblages are recognized. Each succession consists of a basal sandstone that is the initial accumulation of the lake-level rise and lake highstand. Overlying this sandstone are cyclic evaporite and fine-grained clastic deposits of the lake-level fall. These units are modified by desiccation-related processes resulting from lake contraction and desiccation around the lake margins. Subsequent lake-level rise resulted in subaqueous mechanical erosion of clastics and dissolution of interbedded evaporites. In more basinward regions, dissolution of evaporites occurred prior to accumulation of lake highstand units. In the saline lake center, the lake never dried up entirely, and evidence for partial lake desiccation is equivocal. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.