Two-stage vesiculation in the Cohassett flow of the Grande Ronde Basalt, south-central Washington

Abstract

Research Article| September 01, 1987 Two-stage vesiculation in the Cohassett flow of the Grande Ronde Basalt, south-central Washington Kent McMillan; Kent McMillan 1Geosciences Group, Basalt Waste Isolation Project, Rockwell Hanford Operations, Richland, Washington 99352 Search for other works by this author on: GSW Google Scholar Randal W. Cross; Randal W. Cross 1Geosciences Group, Basalt Waste Isolation Project, Rockwell Hanford Operations, Richland, Washington 99352 Search for other works by this author on: GSW Google Scholar Philip E. Long Philip E. Long 1Geosciences Group, Basalt Waste Isolation Project, Rockwell Hanford Operations, Richland, Washington 99352 Search for other works by this author on: GSW Google Scholar Author and Article Information Kent McMillan 1Geosciences Group, Basalt Waste Isolation Project, Rockwell Hanford Operations, Richland, Washington 99352 Randal W. Cross 1Geosciences Group, Basalt Waste Isolation Project, Rockwell Hanford Operations, Richland, Washington 99352 Philip E. Long 1Geosciences Group, Basalt Waste Isolation Project, Rockwell Hanford Operations, Richland, Washington 99352 Publisher: Geological Society of America First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1987) 15 (9): 809–812. https://doi.org/10.1130/0091-7613(1987)15<809:TVITCF>2.0.CO;2 Article history First Online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Tools Icon Tools Get Permissions Search Site Citation Kent McMillan, Randal W. Cross, Philip E. Long; Two-stage vesiculation in the Cohassett flow of the Grande Ronde Basalt, south-central Washington. Geology 1987;; 15 (9): 809–812. doi: https://doi.org/10.1130/0091-7613(1987)15<809:TVITCF>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 The Cohassett flow of the Grande Ronde Basalt contains two vesicular zones separated by 24 m of dense, sparsely vesicular basalt. The vesicular zones represent accumulations of upward-migrating bubbles sequentially frozen-in by the downward passage of the upper solidification front. The separation of the two zones suggests a hiatus in the exsolution of aqueous vapor from the lava. The flow-top vesicular zone formed during and immediately following emplacement of the flow from vapor bubbles nucleated during ascent and eruption, whereas the internal vesicular zone formed after emplacement from bubbles apparently nucleated at the lower solidification front. Homogeneous nucleation of vapor was probably initially driven by large oversaturation pressures in the erupting lava. After emplacement, heterogeneous nucleation of vapor was probably initiated by crystallization in the margins of the flow. 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.