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Particle sizes of andesitic ash fallout from vertical eruptions and co-pyroclastic flow clouds, Volcán de Colima, Mexico

2009; Geological Society of America; Volume: 37; Issue: 10 Linguagem: Inglês

10.1130/g30208a.1

1943-2682

Jason R. Evans, Jacqueline E. Huntoon, William I. Rose, Nick Varley, John Stevenson,

Geology and Paleoclimatology Research

Research Article| October 01, 2009 Particle sizes of andesitic ash fallout from vertical eruptions and co-pyroclastic flow clouds, Volcán de Colima, Mexico Jason R. Evans; Jason R. Evans 1Michigan Technological University, Houghton, Michigan 49931, USA Search for other works by this author on: GSW Google Scholar Jacqueline E. Huntoon; Jacqueline E. Huntoon 1Michigan Technological University, Houghton, Michigan 49931, USA Search for other works by this author on: GSW Google Scholar William I. Rose; William I. Rose 1Michigan Technological University, Houghton, Michigan 49931, USA Search for other works by this author on: GSW Google Scholar Nick R. Varley; Nick R. Varley 2Universidad de Colima, Colima 28040, México Search for other works by this author on: GSW Google Scholar John A. Stevenson John A. Stevenson 3University of Manchester, Manchester M13 9PL, UK Search for other works by this author on: GSW Google Scholar Author and Article Information Jason R. Evans 1Michigan Technological University, Houghton, Michigan 49931, USA Jacqueline E. Huntoon 1Michigan Technological University, Houghton, Michigan 49931, USA William I. Rose 1Michigan Technological University, Houghton, Michigan 49931, USA Nick R. Varley 2Universidad de Colima, Colima 28040, México John A. Stevenson 3University of Manchester, Manchester M13 9PL, UK Publisher: Geological Society of America Received: 07 Mar 2009 Revision Received: 23 May 2009 Accepted: 29 May 2009 First Online: 03 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 © 2009 Geological Society of America Geology (2009) 37 (10): 935–938. https://doi.org/10.1130/G30208A.1 Article history Received: 07 Mar 2009 Revision Received: 23 May 2009 Accepted: 29 May 2009 First Online: 03 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Jason R. Evans, Jacqueline E. Huntoon, William I. Rose, Nick R. Varley, John A. Stevenson; Particle sizes of andesitic ash fallout from vertical eruptions and co-pyroclastic flow clouds, Volcán de Colima, Mexico. Geology 2009;; 37 (10): 935–938. doi: https://doi.org/10.1130/G30208A.1 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 We report particle-size distributions for andesitic ash fall from vertical eruptions and clouds above block-and-ash flows at Volcán de Colima, Mexico, during 2004–2006. We analyzed 17 samples using laser diffraction: 11 from vertical eruptions and 6 from block-and-ash flows (co-pyroclastic flow ash). Vertical eruptions produce well-sorted fall deposits, whereas co-pyroclastic fall deposits are poorly sorted, with high proportions of very fine grained ash (<30 μm). Statistical analysis shows particle-size distributions of vertical eruptions are more leptokurtic (peaked) than co-pyroclastic samples. Deconvolution of grain-size histograms shows that co-pyroclastic samples have at least one subpopulation with a mode of 8.3–8.7 ϕ (2.4–3.1 μm). Estimates of the number of particles in different size ranges show that co-pyroclastic samples contain much greater numbers of very fine particles than vertical eruption samples. Our results provide no direct evidence that milling or comminution produces hazardous fine ash particles in pyroclastic flows, but are consistent with that interpretation. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.