Authigenic Aluminosilicate Minerals in the Tuffaceous Rocks of the Green River Formation, Wyoming

Abstract

Research Article| March 01, 1972 Authigenic Aluminosilicate Minerals in the Tuffaceous Rocks of the Green River Formation, Wyoming RONALD C SURDAM; RONALD C SURDAM Department of Geology, University of Wyoming, P.O. Box 3006, Laramie, Wyoming 82070 Search for other works by this author on: GSW Google Scholar RONALD D PARKER RONALD D PARKER Department of Geology, University of Wyoming, P.O. Box 3006, Laramie, Wyoming 82070 Search for other works by this author on: GSW Google Scholar Author and Article Information RONALD C SURDAM Department of Geology, University of Wyoming, P.O. Box 3006, Laramie, Wyoming 82070 RONALD D PARKER Department of Geology, University of Wyoming, P.O. Box 3006, Laramie, Wyoming 82070 Publisher: Geological Society of America Received: 31 Aug 1971 First Online: 02 Mar 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Copyright © 1972, The Geological Society of America, Inc. Copyright is not claimed on any material prepared by U.S. government employees within the scope of their employment. GSA Bulletin (1972) 83 (3): 689–700. https://doi.org/10.1130/0016-7606(1972)83[689:AAMITT]2.0.CO;2 Article history Received: 31 Aug 1971 First Online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation RONALD C SURDAM, RONALD D PARKER; Authigenic Aluminosilicate Minerals in the Tuffaceous Rocks of the Green River Formation, Wyoming. GSA Bulletin 1972;; 83 (3): 689–700. doi: https://doi.org/10.1130/0016-7606(1972)83[689:AAMITT]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 Green River Formation of Wyoming was deposited in a large lake, Lake Gosiute, during Eocene time. Throughout Lake Gosiute's existence, nearby volcanism supplied debris to the lake basin. Tuffs are abundant and widespread in the formation and were highly reactive units. Reaction between glass and the lake waters produced authigenic clay minerals, mordenite or clinoptilolite, analcime, and potassium feldspar. Some tuffs are almost entirely replaced by authigenic aluminosilicate minerals.The alteration of the tuffs shows a systematic pattern with the clay mineral and zeolite alteration restricted to facies formed in relatively fresh water, and the feldspar alteration is confined to a hypersaline facies. We infer that the lake water ranged from fresh or brackish (SiO2 = 10 ppm, K = 50 ppm, Na = 1,000 ppm) at a pH of 8.0 during the "fresh-water stage" to hypersaline (SiO2 = 1,000 ppm, K = 5,000 ppm, Na = 100,000 ppm) at a pH of 9.0 to 10.0 during the most saline and alkaline stage. Brines were formed primarily by evaporative concentration. Organisms, reflected by abundant high-yield oil shales, thrived during the freshwater episodes, but were apparently absent or of minor significance during the hypersaline episodes; this is reflected by the presence of thick beds of trona and halite. 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.