Research Article| June 01, 1992 Lithic-dominated pyroclastic flows at Galeras volcano, Colombia—An unrecognized volcanic hazard Marta Lucia Calvache V.; Marta Lucia Calvache V. 1Department of Geology, Arizona State University, Tempe, Arizona 85287-1404 Search for other works by this author on: GSW Google Scholar Stanley N. Williams Stanley N. Williams 1Department of Geology, Arizona State University, Tempe, Arizona 85287-1404 Search for other works by this author on: GSW Google Scholar Author and Article Information Marta Lucia Calvache V. 1Department of Geology, Arizona State University, Tempe, Arizona 85287-1404 Stanley N. Williams 1Department of Geology, Arizona State University, Tempe, Arizona 85287-1404 Publisher: Geological Society of America First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1992) 20 (6): 539–542. https://doi.org/10.1130/0091-7613(1992)020<0539:LDPFAG>2.3.CO;2 Article history First Online: 02 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 Marta Lucia Calvache V., Stanley N. Williams; Lithic-dominated pyroclastic flows at Galeras volcano, Colombia—An unrecognized volcanic hazard. Geology 1992;; 20 (6): 539–542. doi: https://doi.org/10.1130/0091-7613(1992)020<0539:LDPFAG>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 SocietyGeology Search Advanced Search Abstract Yellow, hydrothermally altered, lithic-dominated pyroclastic breccia deposits, having only a minor juvenile component, at Galeras volcano, Colombia, contain evidence that they were emplaced as hot, fluidized, true pyroclastic flows. The distribution of the flows around the caldera rim, their transport mechanisms inferred from grain-size analyses, and the presence of charcoal and coarse channel and fine overbank facies indicate that these deposits were emplaced as true pyroclastic flows. These deposits are the result of a regularly repeated eruption sequence, involving clearing of vent material as a prelude to more typical pumiceous pyroclastic flows. Recognition of the mode of origin of these deposits is important in terms of understanding Vulcanian-type eruption and flow- emplacement mechanisms. Failure to recognize the explosive eruption origin of these deposits at Galeras and other volcanoes could result in serious underestimation of potential hazards. 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.