<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html> <head> <title>UTas ePrints - Syn-eruptive chaotic breccia on Kos, Greece, associated with an energetic pyroclastic flow</title> <script type="text/javascript" src="http://eprints.utas.edu.au/javascript/auto.js"><!-- padder --></script> <style type="text/css" media="screen">@import url(http://eprints.utas.edu.au/style/auto.css);</style> <style type="text/css" media="print">@import url(http://eprints.utas.edu.au/style/print.css);</style> <link rel="icon" href="/images/eprints/favicon.ico" type="image/x-icon" /> <link rel="shortcut icon" href="/images/eprints/favicon.ico" type="image/x-icon" /> <link rel="Top" href="http://eprints.utas.edu.au/" /> <link rel="Search" href="http://eprints.utas.edu.au/cgi/search" /> <meta content="Allen, S.R." name="eprints.creators_name" /> <meta content="McPhie, J." name="eprints.creators_name" /> <meta content="Sharon.Allen@utas.edu.au" name="eprints.creators_id" /> <meta content="J.McPhie@utas.edu.au" name="eprints.creators_id" /> <meta content="article" name="eprints.type" /> <meta content="2007-10-11 01:16:55" name="eprints.datestamp" /> <meta content="2008-01-08 15:30:00" name="eprints.lastmod" /> <meta content="show" name="eprints.metadata_visibility" /> <meta content="Syn-eruptive chaotic breccia on Kos, Greece, associated with an energetic pyroclastic flow" name="eprints.title" /> <meta content="pub" name="eprints.ispublished" /> <meta content="260100" name="eprints.subjects" /> <meta content="restricted" name="eprints.full_text_status" /> <meta content="Kos Plateau Tuff · Caldera-forming eruption · Pyroclastic flow · Syn-eruptive chaotic breccia, · Shear liquification · Debris avalanche" name="eprints.keywords" /> <meta content="The original publication is available at www.springerlink.com" name="eprints.note" /> <meta content="The climax of the Kos Plateau Tuff (KPT) eruption (eastern Aegean, Greece) generated a highly energetic, coarse-grained, lithic-rich, pyroclastic flow. In most places on Kos, the deposit from this event is an ignimbrite (ignimbrite El) that comprises a basal, coarsegrained, lithic breccia and overlying pumiceous part, above a planar, strongly erosional lower contact. However, along the northern coast of central Kos, “normal” ignimbrite El overlies a hummocky, 6-m-thick layer of chaotic breccia comprising mingled-to-pervasively mixed ignimbrite El and unconsolidated sediment. The surface morphology of the chaotic breccia and its internal texture resemble those of a debris-avalanche deposit, but the breccia is neither proximal nor downcurrent of steep topography. The lower part of the chaotic breccia comprises distinct domains of unconsolidated sediment or lower KPT units that are deformed and/or mingled with pumiceous ignimbrite. The upper part is dominated by a matrix of mingled-to-pervasively mixed ignimbrite and sediment that contains sediment domains as large as 2–10 m in diameter. Such large intact allochthonous domains are best preserved at the top of the chaotic breccia and form the hummocks. The chaotic breccia formed synchronously with the passage of a highly energetic pyroclastic flow where it traversed wet, unconsolidated sediment. Shear-induced liquification, together with possible ground shaking associated with the eruption, probably caused failure. Part of the unconsolidated substrate and basal part of ignimbrite El were dislodged and resedimented a short distance (tens to hundreds of metres)downcurrent. The lower part records deformation and disintegration of the substrate induced by the overriding, shearing flow. Mingling and deformation of the poorly consolidated material occurred as a result of within-flow lateral shear. Attenuated worm burrows within the sediment domains, and pinch-and-swell and flame structures within the mingled domains, preserve evidence of shear in the lower part. The upper part was transported downcurrent above a zone of shear failure. Internal heterogeneities in physical properties resulted in variable strain rates causing some domains to be pervasively mixed while others remained intact. Intact large unconsolidated domains at the top were transported mostly above the zone of shearing." name="eprints.abstract" /> <meta content="2001-10" name="eprints.date" /> <meta content="published" name="eprints.date_type" /> <meta content="Bulletin of Volcanology" name="eprints.publication" /> <meta content="63" name="eprints.volume" /> <meta content="6" name="eprints.number" /> <meta content="421-432" name="eprints.pagerange" /> <meta content="10.1007/s004450100162" name="eprints.id_number" /> <meta content="TRUE" name="eprints.refereed" /> <meta content="0258-8900" name="eprints.issn" /> <meta content="http://dx.doi.org/10.1007/s004450100162" name="eprints.official_url" /> <meta content="Allen SR (2001) Reconstruction of a major caldera-forming eruption from pyroclastic deposit characteristics: Kos Plateau Tuff, eastern Aegean Sea. J Volcanol Geotherm Res 105:141–162 Allen SR, Cas RAF (1998) Lateral variations within coarse co-ignimbrite lithic breccias of the Kos Plateau Tuff, Greece. Bull Volcanol 59:356–377 Allen SR, Cas RAF (2001) Transport of pyroclastic flows across the sea during the explosive, rhyolitic eruption of the Kos Plateau Tuff, Greece. Bull Volcanol 62:441–456 Allen SR, Stadlbauer E, Keller J (1999) Stratigraphy of the Kos Plateau Tuff: product of a major Quaternary explosive rhyolitic eruption in the eastern Aegean, Greece. Int J Earth Sci 88:132–156 Bailey RA, Carr RG (1994) Physical geology and eruptive history of the Matahina ignimbrite, Taupo volcanic zone, North Island, New Zealand. N Z J Geol Geophys 37:319–344 Bond A, Sparks RSJ (1976) The Minoan eruption of Santorini, Greece. J Geol Soc Lond 132:1–16 Chappell J, Shackleton NJ (1986) Oxygen isotopes and sea level. Nature 324:137–140 Fisher RV (1971) Features of coarse-grained, high concentration fluids and their deposits. J Sediment Petrol 41:916–927 Fisher RV, Schmincke H-U (1984) Pyroclastic rocks. Springer, Berlin Heidelberg New York, pp 297–311 Flemming NC (1978) Holocene eustatic changes and coastal tectonics in the northeast Mediterranean: implications for models of crustal consumption. Phil Trans R Soc Lond A289:405– 458 Francis PW, Wells GL (1988) Landsat thematic mapper observations of debris avalanche deposits in the central Andes. Bull Volcanol 50:258–278 Glicken G (1991) Sedimentary architecture of large volcanic-debris avalanches. SEPM Spec Publ 45:99–106 Howells MF, Campbell SDG, Reedman AJ (1985) Isolated pods of subaqueous welded ash-flow tuff: a distal facies of the Capel Curig Volcanic Formation (Ordovician), North Wales. Geol Mag 122:175–180 Johnson AM (1970) Physical processes in geology. Freeman, San Francisco Kokelaar BP (1982) Fluidisation of wet sediments during the emplacement and cooling of various igneous bodies. J Geol Soc Lond 139:21–33 LePichon X, Angelier J (1979) The Hellenic arc and trench system: a key to the neotectonic evolution of the eastern Mediterranean area. Tectonophysics 60:1–42 Lipman PW (1976) Caldera-collapse breccias in the western San Juan Mountains, Colorado. Geol Soc Am Bull 87:1397–1410 Naranjo JA, Francis P (1987) High velocity debris avalanche at Lastarria volcano in the north Chilean Andes. Bull Volcanol 49:509–514 Nichols RJ (1995) The liquification and remobilization of sandy sediments. Geol Soc Lond Spec Publ 94:63–76 Palmer BA, Alloway BV, Neall VE (1991) Volcanic-debris-avalanche deposits in New Zealand-lithofacies organization in unconfined, wet-avalanche flow. SEPM Spec Publ 45:89–98 Pierson TC, Costa JE (1987) A rheologic classification of subaerial sediment-water flows. Geol Soc Am Rev Eng Geol 7:1–12 Self S, Rampino MR (1981) The 1883 eruption of Krakatau. Nature 294:699–704 Siebe C, Komorowski J-C, Sheridan MF (1992) Morphology and emplacement of an unusual debris-avalanche deposit at Jocotitlán volcano, Central Mexico. Bull Volcanol 54:573–589 Siebert L (1984) Large volcanic debris avalanches: characteristics of source areas, deposits, and associated eruptions. J Volcanol Geotherm Res 22:163–197 Stoopes G, Sheridan MF (1992) Giant debris avalanches from the Colima volcanic complex, Mexico: implications for long-runout landslides (>100 km) and hazard assessment. Geology 20:299–302 Takarada S, Ui T, Yamamoto Y (1999) Depositional features and transportation mechanism of valley-filling Iwasegawa and Kaida debris avalanches, Japan. Bull Volcanol 60:508–522 Ui T, Yamamoto H, Suzuki-Kamata K (1986) Characterisation of debris avalanche deposits in Japan. J Volcanol Geotherm Res 29:231–243 Voight B, Glicken H, Janda RJ, Douglass PM (1981) Catastrophic rockslide avalanche of May 18. US Geol Surv Prof Pap 1250:347–377 Voight B, Janda RJ, Glicken H, Douglass PM (1983) Nature and mechanics of the Mount St. Helens rockslide-avalanche of 18 May 1980. Geotechnique 33:243–273 Willmann R (1983) Neogen und jungtertiäre Entwicklung der Insel Kos (Ägäis, Grienchenland). Geol Rundsch 72:815–860 Wilson CJN, Walker GPL (1985) The Taupo eruption, New Zealand. I. General aspects. Phil Trans R Soc Lond A314:199– 228" name="eprints.referencetext" /> <meta content="Allen, S.R. and McPhie, J. (2001) Syn-eruptive chaotic breccia on Kos, Greece, associated with an energetic pyroclastic flow. Bulletin of Volcanology, 63 (6). pp. 421-432. ISSN 0258-8900" name="eprints.citation" /> <meta content="http://eprints.utas.edu.au/2082/1/Allen.McPhie.BV.2001.pdf" name="eprints.document_url" /> <link rel="schema.DC" href="http://purl.org/DC/elements/1.0/" /> <meta content="Syn-eruptive chaotic breccia on Kos, Greece, associated with an energetic pyroclastic flow" name="DC.title" /> <meta content="Allen, S.R." name="DC.creator" /> <meta content="McPhie, J." name="DC.creator" /> <meta content="260100 Geology" name="DC.subject" /> <meta content="The climax of the Kos Plateau Tuff (KPT) eruption (eastern Aegean, Greece) generated a highly energetic, coarse-grained, lithic-rich, pyroclastic flow. In most places on Kos, the deposit from this event is an ignimbrite (ignimbrite El) that comprises a basal, coarsegrained, lithic breccia and overlying pumiceous part, above a planar, strongly erosional lower contact. However, along the northern coast of central Kos, “normal” ignimbrite El overlies a hummocky, 6-m-thick layer of chaotic breccia comprising mingled-to-pervasively mixed ignimbrite El and unconsolidated sediment. The surface morphology of the chaotic breccia and its internal texture resemble those of a debris-avalanche deposit, but the breccia is neither proximal nor downcurrent of steep topography. The lower part of the chaotic breccia comprises distinct domains of unconsolidated sediment or lower KPT units that are deformed and/or mingled with pumiceous ignimbrite. The upper part is dominated by a matrix of mingled-to-pervasively mixed ignimbrite and sediment that contains sediment domains as large as 2–10 m in diameter. Such large intact allochthonous domains are best preserved at the top of the chaotic breccia and form the hummocks. The chaotic breccia formed synchronously with the passage of a highly energetic pyroclastic flow where it traversed wet, unconsolidated sediment. Shear-induced liquification, together with possible ground shaking associated with the eruption, probably caused failure. Part of the unconsolidated substrate and basal part of ignimbrite El were dislodged and resedimented a short distance (tens to hundreds of metres)downcurrent. The lower part records deformation and disintegration of the substrate induced by the overriding, shearing flow. Mingling and deformation of the poorly consolidated material occurred as a result of within-flow lateral shear. Attenuated worm burrows within the sediment domains, and pinch-and-swell and flame structures within the mingled domains, preserve evidence of shear in the lower part. The upper part was transported downcurrent above a zone of shear failure. Internal heterogeneities in physical properties resulted in variable strain rates causing some domains to be pervasively mixed while others remained intact. Intact large unconsolidated domains at the top were transported mostly above the zone of shearing." name="DC.description" /> <meta content="2001-10" name="DC.date" /> <meta content="Article" name="DC.type" /> <meta content="PeerReviewed" name="DC.type" /> <meta content="application/pdf" name="DC.format" /> <meta content="http://eprints.utas.edu.au/2082/1/Allen.McPhie.BV.2001.pdf" name="DC.identifier" /> <meta content="http://dx.doi.org/10.1007/s004450100162" name="DC.relation" /> <meta content="Allen, S.R. and McPhie, J. (2001) Syn-eruptive chaotic breccia on Kos, Greece, associated with an energetic pyroclastic flow. Bulletin of Volcanology, 63 (6). pp. 421-432. ISSN 0258-8900" name="DC.identifier" /> <meta content="http://eprints.utas.edu.au/2082/" name="DC.relation" /> <link rel="alternate" href="http://eprints.utas.edu.au/cgi/export/2082/BibTeX/epprod-eprint-2082.bib" title="BibTeX" type="text/plain" /> <link rel="alternate" href="http://eprints.utas.edu.au/cgi/export/2082/ContextObject/epprod-eprint-2082.xml" title="OpenURL ContextObject" type="text/xml" /> <link rel="alternate" href="http://eprints.utas.edu.au/cgi/export/2082/ContextObject::Dissertation/epprod-eprint-2082.xml" title="OpenURL Dissertation" type="text/xml" /> <link rel="alternate" href="http://eprints.utas.edu.au/cgi/export/2082/ContextObject::Journal/epprod-eprint-2082.xml" title="OpenURL Journal" type="text/xml" /> <link rel="alternate" href="http://eprints.utas.edu.au/cgi/export/2082/DC/epprod-eprint-2082.txt" title="Dublin Core" type="text/plain" /> <link rel="alternate" href="http://eprints.utas.edu.au/cgi/export/2082/DIDL/epprod-eprint-2082.xml" title="DIDL" type="text/xml" /> <link rel="alternate" href="http://eprints.utas.edu.au/cgi/export/2082/EndNote/epprod-eprint-2082.enw" title="EndNote" type="text/plain" /> <link rel="alternate" href="http://eprints.utas.edu.au/cgi/export/2082/HTML/epprod-eprint-2082.html" title="HTML Citation" type="text/html; charset=utf-8" /> <link rel="alternate" href="http://eprints.utas.edu.au/cgi/export/2082/METS/epprod-eprint-2082.xml" title="METS" type="text/xml" /> <link rel="alternate" href="http://eprints.utas.edu.au/cgi/export/2082/MODS/epprod-eprint-2082.xml" title="MODS" type="text/xml" /> <link rel="alternate" href="http://eprints.utas.edu.au/cgi/export/2082/RIS/epprod-eprint-2082.ris" title="Reference Manager" type="text/plain" /> <link rel="alternate" href="http://eprints.utas.edu.au/cgi/export/2082/Refer/epprod-eprint-2082.refer" title="Refer" type="text/plain" /> <link rel="alternate" href="http://eprints.utas.edu.au/cgi/export/2082/Simple/epprod-eprint-2082text" title="Simple Metadata" type="text/plain" /> <link rel="alternate" href="http://eprints.utas.edu.au/cgi/export/2082/Text/epprod-eprint-2082.txt" title="ASCII Citation" type="text/plain; charset=utf-8" /> <link rel="alternate" href="http://eprints.utas.edu.au/cgi/export/2082/XML/epprod-eprint-2082.xml" title="EP3 XML" type="text/xml" /> </head> <body bgcolor="#ffffff" text="#000000" onLoad="loadRoutine(); MM_preloadImages('images/eprints/ePrints_banner_r5_c5_f2.gif','images/eprints/ePrints_banner_r5_c7_f2.gif','images/eprints/ePrints_banner_r5_c8_f2.gif','images/eprints/ePrints_banner_r5_c9_f2.gif','images/eprints/ePrints_banner_r5_c10_f2.gif','images/eprints/ePrints_banner_r5_c11_f2.gif','images/eprints/ePrints_banner_r6_c4_f2.gif')"> <div class="ep_noprint"><noscript><style type="text/css">@import url(http://eprints.utas.edu.au/style/nojs.css);</style></noscript></div> <table width="795" border="0" cellspacing="0" cellpadding="0"> <tr> <td><script language="JavaScript1.2">mmLoadMenus();</script> <table border="0" cellpadding="0" cellspacing="0" width="795"> <!-- fwtable fwsrc="eprints_banner_final2.png" fwbase="ePrints_banner.gif" fwstyle="Dreamweaver" fwdocid = "1249563342" fwnested="0" --> <tr> <td><img src="/images/eprints/spacer.gif" width="32" height="1" border="0" alt="" /></td> <td><img src="/images/eprints/spacer.gif" width="104" height="1" border="0" alt="" /></td> <td><img src="/images/eprints/spacer.gif" width="44" height="1" border="0" alt="" /></td> <td><img src="/images/eprints/spacer.gif" width="105" height="1" border="0" alt="" /></td> <td><img src="/images/eprints/spacer.gif" width="41" height="1" border="0" alt="" /></td> <td><img src="/images/eprints/spacer.gif" width="16" height="1" border="0" alt="" /></td> <td><img src="/images/eprints/spacer.gif" width="68" height="1" border="0" alt="" /></td> <td><img src="/images/eprints/spacer.gif" width="68" height="1" border="0" alt="" /></td> <td><img src="/images/eprints/spacer.gif" width="68" height="1" border="0" alt="" /></td> <td><img src="/images/eprints/spacer.gif" width="82" height="1" border="0" alt="" /></td> <td><img src="/images/eprints/spacer.gif" width="69" height="1" border="0" alt="" /></td> <td><img src="/images/eprints/spacer.gif" width="98" height="1" border="0" alt="" /></td> <td><img src="/images/eprints/spacer.gif" width="1" height="1" border="0" alt="" /></td> </tr> <tr> <td colspan="12"><img name="ePrints_banner_r1_c1" src="/images/eprints/ePrints_banner_r1_c1.gif" width="795" height="10" border="0" alt="" /></td> <td><img src="/images/eprints/spacer.gif" width="1" height="10" border="0" alt="" /></td> </tr> <tr> <td rowspan="6"><img name="ePrints_banner_r2_c1" src="/images/eprints/ePrints_banner_r2_c1.gif" width="32" height="118" border="0" alt="" /></td> <td rowspan="5"><a href="http://www.utas.edu.au/"><img name="ePrints_banner_r2_c2" src="/images/eprints/ePrints_banner_r2_c2.gif" width="104" height="103" border="0" alt="" /></a></td> <td colspan="10"><img name="ePrints_banner_r2_c3" src="/images/eprints/ePrints_banner_r2_c3.gif" width="659" height="41" border="0" alt="" /></td> <td><img src="/images/eprints/spacer.gif" width="1" height="41" border="0" alt="" /></td> </tr> <tr> <td colspan="3"><a href="http://eprints.utas.edu.au/"><img name="ePrints_banner_r3_c3" src="/images/eprints/ePrints_banner_r3_c3.gif" width="190" height="31" border="0" alt="" /></a></td> <td rowspan="2" colspan="7"><img name="ePrints_banner_r3_c6" src="/images/eprints/ePrints_banner_r3_c6.gif" width="469" height="37" border="0" alt="" /></td> <td><img src="/images/eprints/spacer.gif" width="1" height="31" border="0" alt="" /></td> </tr> <tr> <td colspan="3"><img name="ePrints_banner_r4_c3" src="/images/eprints/ePrints_banner_r4_c3.gif" width="190" height="6" border="0" alt="" /></td> <td><img src="/images/eprints/spacer.gif" width="1" height="6" border="0" alt="" /></td> </tr> <tr> <td colspan="2"><img name="ePrints_banner_r5_c3" src="/images/eprints/ePrints_banner_r5_c3.gif" width="149" height="1" border="0" alt="" /></td> <td rowspan="2" colspan="2"><a href="/information.html" onMouseOut="MM_swapImgRestore();MM_startTimeout()" onMouseOver="MM_showMenu(window.mm_menu_0821132634_0,0,25,null,'ePrints_banner_r5_c5');MM_swapImage('ePrints_banner_r5_c5','','/images/eprints/ePrints_banner_r5_c5_f2.gif',1);"><img name="ePrints_banner_r5_c5" src="/images/eprints/ePrints_banner_r5_c5.gif" width="57" height="25" border="0" alt="About" /></a></td> <td rowspan="2"><a href="/view/" onMouseOut="MM_swapImgRestore();MM_startTimeout()" onMouseOver="MM_showMenu(window.mm_menu_0821133021_1,0,25,null,'ePrints_banner_r5_c7');MM_swapImage('ePrints_banner_r5_c7','','/images/eprints/ePrints_banner_r5_c7_f2.gif',1);"><img name="ePrints_banner_r5_c7" src="/images/eprints/ePrints_banner_r5_c7.gif" width="68" height="25" border="0" alt="Browse" /></a></td> <td rowspan="2"><a href="/perl/search/simple" onMouseOut="MM_swapImgRestore();MM_startTimeout()" onMouseOver="MM_showMenu(window.mm_menu_0821133201_2,0,25,null,'ePrints_banner_r5_c8');MM_swapImage('ePrints_banner_r5_c8','','/images/eprints/ePrints_banner_r5_c8_f2.gif',1);"><img name="ePrints_banner_r5_c8" src="/images/eprints/ePrints_banner_r5_c8.gif" width="68" height="25" border="0" alt="Search" /></a></td> <td rowspan="2"><a href="/perl/register" onMouseOut="MM_swapImgRestore();MM_startTimeout();" onMouseOver="MM_showMenu(window.mm_menu_1018171924_3,0,25,null,'ePrints_banner_r5_c9');MM_swapImage('ePrints_banner_r5_c9','','/images/eprints/ePrints_banner_r5_c9_f2.gif',1);"><img name="ePrints_banner_r5_c9" src="/images/eprints/ePrints_banner_r5_c9.gif" width="68" height="25" border="0" alt="register" /></a></td> <td rowspan="2"><a href="/perl/users/home" onMouseOut="MM_swapImgRestore();MM_startTimeout()" onMouseOver="MM_showMenu(window.mm_menu_0821133422_4,0,25,null,'ePrints_banner_r5_c10');MM_swapImage('ePrints_banner_r5_c10','','/images/eprints/ePrints_banner_r5_c10_f2.gif',1);"><img name="ePrints_banner_r5_c10" src="/images/eprints/ePrints_banner_r5_c10.gif" width="82" height="25" border="0" alt="user area" /></a></td> <td rowspan="2"><a href="/help/" onMouseOut="MM_swapImgRestore();MM_startTimeout()" onMouseOver="MM_showMenu(window.mm_menu_0821133514_5,0,25,null,'ePrints_banner_r5_c11');MM_swapImage('ePrints_banner_r5_c11','','/images/eprints/ePrints_banner_r5_c11_f2.gif',1);"><img name="ePrints_banner_r5_c11" src="/images/eprints/ePrints_banner_r5_c11.gif" width="69" height="25" border="0" alt="Help" /></a></td> <td rowspan="3" colspan="4"><img name="ePrints_banner_r5_c12" src="/images/eprints/ePrints_banner_r5_c12.gif" width="98" height="40" border="0" alt="" /></td> <td><img src="/images/eprints/spacer.gif" width="1" height="1" border="0" alt="" /></td> </tr> <tr> <td rowspan="2"><img name="ePrints_banner_r6_c3" src="/images/eprints/ePrints_banner_r6_c3.gif" width="44" height="39" border="0" alt="ePrints home" /></td> <td><a href="/" onMouseOut="MM_swapImgRestore()" onMouseOver="MM_swapImage('ePrints_banner_r6_c4','','/images/eprints/ePrints_banner_r6_c4_f2.gif',1);"><img name="ePrints_banner_r6_c4" src="/images/eprints/ePrints_banner_r6_c4.gif" width="105" height="24" border="0" alt="ePrints home" /></a></td> <td><img src="/images/eprints/spacer.gif" width="1" height="24" border="0" alt="" /></td> </tr> <tr> <td><img name="ePrints_banner_r7_c2" src="/images/eprints/ePrints_banner_r7_c2.gif" width="104" height="15" border="0" alt="" /></td> <td colspan="8"><img name="ePrints_banner_r7_c4" src="/images/eprints/ePrints_banner_r7_c4.gif" width="517" height="15" border="0" alt="" /></td> <td><img src="/images/eprints/spacer.gif" width="1" height="15" border="0" alt="" /></td> </tr> </table></td> </tr> <tr><td><table width="100%" style="font-size: 90%; border: solid 1px #ccc; padding: 3px"><tr> <td align="left"><a href="http://eprints.utas.edu.au/cgi/users/home">Login</a> | <a href="http://eprints.utas.edu.au/cgi/register">Create Account</a></td> <td align="right" style="white-space: nowrap"> <form method="get" accept-charset="utf-8" action="http://eprints.utas.edu.au/cgi/search" style="display:inline"> <input class="ep_tm_searchbarbox" size="20" type="text" name="q" /> <input class="ep_tm_searchbarbutton" value="Search" type="submit" name="_action_search" /> <input type="hidden" name="_order" value="bytitle" /> <input type="hidden" name="basic_srchtype" value="ALL" /> <input type="hidden" name="_satisfyall" value="ALL" /> </form> </td> </tr></table></td></tr> <tr> <td class="toplinks"><!-- InstanceBeginEditable name="content" --> <div align="center"> <table width="720" class="ep_tm_main"><tr><td align="left"> <h1 class="ep_tm_pagetitle">Syn-eruptive chaotic breccia on Kos, Greece, associated with an energetic pyroclastic flow</h1> <p style="margin-bottom: 1em" class="not_ep_block"><span class="person_name">Allen, S.R.</span> and <span class="person_name">McPhie, J.</span> (2001) <xhtml:em>Syn-eruptive chaotic breccia on Kos, Greece, associated with an energetic pyroclastic flow.</xhtml:em> Bulletin of Volcanology, 63 (6). pp. 421-432. ISSN 0258-8900</p><p style="margin-bottom: 1em" class="not_ep_block"></p><table style="margin-bottom: 1em" class="not_ep_block"><tr><td valign="top" style="text-align:center"><a href="http://eprints.utas.edu.au/2082/1/Allen.McPhie.BV.2001.pdf"><img alt="[img]" src="http://eprints.utas.edu.au/style/images/fileicons/application_pdf.png" class="ep_doc_icon" border="0" /></a></td><td valign="top"><a href="http://eprints.utas.edu.au/2082/1/Allen.McPhie.BV.2001.pdf"><span class="ep_document_citation">PDF</span></a> - Full text restricted - Requires a PDF viewer<br />584Kb</td><td><form method="get" accept-charset="utf-8" action="http://eprints.utas.edu.au/cgi/request_doc"><input accept-charset="utf-8" value="2617" name="docid" type="hidden" /><div class=""><input value="Request a copy" name="_action_null" class="ep_form_action_button" onclick="return EPJS_button_pushed( '_action_null' )" type="submit" /> </div></form></td></tr></table><p style="margin-bottom: 1em" class="not_ep_block">Official URL: <a href="http://dx.doi.org/10.1007/s004450100162">http://dx.doi.org/10.1007/s004450100162</a></p><div class="not_ep_block"><h2>Abstract</h2><p style="padding-bottom: 16px; text-align: left; margin: 1em auto 0em auto">The climax of the Kos Plateau Tuff (KPT) eruption (eastern Aegean, Greece) generated a highly energetic, coarse-grained, lithic-rich, pyroclastic flow. In most places on Kos, the deposit from this event is an ignimbrite (ignimbrite El) that comprises a basal, coarsegrained, lithic breccia and overlying pumiceous part, above a planar, strongly erosional lower contact. However, along the northern coast of central Kos, “normal” ignimbrite El overlies a hummocky, 6-m-thick layer of chaotic breccia comprising mingled-to-pervasively mixed ignimbrite El and unconsolidated sediment. The surface morphology of the chaotic breccia and its internal texture resemble those of a debris-avalanche deposit, but the breccia is neither proximal nor downcurrent of steep topography. The lower part of the chaotic breccia comprises distinct domains of unconsolidated sediment or lower KPT units that are deformed and/or mingled with pumiceous ignimbrite. The upper part is dominated by a matrix of mingled-to-pervasively mixed ignimbrite and sediment that contains sediment domains as large as 2–10 m in diameter. Such large intact allochthonous domains are best preserved at the top of the chaotic breccia and form the hummocks. The chaotic breccia formed synchronously with the passage of a highly energetic pyroclastic flow where it traversed wet, unconsolidated sediment. Shear-induced liquification, together with possible ground shaking associated with the eruption, probably caused failure. Part of the unconsolidated substrate and basal part of ignimbrite El were dislodged and resedimented a short distance (tens to hundreds of metres)downcurrent. The lower part records deformation and disintegration of the substrate induced by the overriding, shearing flow. Mingling and deformation of the poorly consolidated material occurred as a result of within-flow lateral shear. Attenuated worm burrows within the sediment domains, and pinch-and-swell and flame structures within the mingled domains, preserve evidence of shear in the lower part. The upper part was transported downcurrent above a zone of shear failure. Internal heterogeneities in physical properties resulted in variable strain rates causing some domains to be pervasively mixed while others remained intact. Intact large unconsolidated domains at the top were transported mostly above the zone of shearing.</p></div><table style="margin-bottom: 1em" cellpadding="3" class="not_ep_block" border="0"><tr><th valign="top" class="ep_row">Item Type:</th><td valign="top" class="ep_row">Article</td></tr><tr><th valign="top" class="ep_row">Additional Information:</th><td valign="top" class="ep_row">The original publication is available at www.springerlink.com</td></tr><tr><th valign="top" class="ep_row">Keywords:</th><td valign="top" class="ep_row">Kos Plateau Tuff · Caldera-forming eruption · Pyroclastic flow · Syn-eruptive chaotic breccia, · Shear liquification · Debris avalanche</td></tr><tr><th valign="top" class="ep_row">Subjects:</th><td valign="top" class="ep_row"><a href="http://eprints.utas.edu.au/view/subjects/260100.html">260000 Earth Sciences > 260100 Geology</a></td></tr><tr><th valign="top" class="ep_row">ID Code:</th><td valign="top" class="ep_row">2082</td></tr><tr><th valign="top" class="ep_row">Deposited By:</th><td valign="top" class="ep_row"><span class="ep_name_citation"><span class="person_name">Mrs Katrina Keep</span></span></td></tr><tr><th valign="top" class="ep_row">Deposited On:</th><td valign="top" class="ep_row">11 Oct 2007 12:16</td></tr><tr><th valign="top" class="ep_row">Last Modified:</th><td valign="top" class="ep_row">09 Jan 2008 02:30</td></tr><tr><th valign="top" class="ep_row">ePrint Statistics:</th><td valign="top" class="ep_row"><a target="ePrintStats" href="/es/index.php?action=show_detail_eprint;id=2082;">View statistics for this ePrint</a></td></tr></table><p align="right">Repository Staff Only: <a href="http://eprints.utas.edu.au/cgi/users/home?screen=EPrint::View&eprintid=2082">item control page</a></p> </td></tr></table> </div> <!-- InstanceEndEditable --></td> </tr> <tr> <td><!-- #BeginLibraryItem "/Library/footer_eprints.lbi" --> <table width="795" border="0" align="left" cellpadding="0" class="footer"> <tr valign="top"> <td colspan="2"><div align="center"><a href="http://www.utas.edu.au">UTAS home</a> | <a href="http://www.utas.edu.au/library/">Library home</a> | <a href="/">ePrints home</a> | <a href="/contact.html">contact</a> | <a href="/information.html">about</a> | <a href="/view/">browse</a> | <a href="/perl/search/simple">search</a> | <a href="/perl/register">register</a> | <a href="/perl/users/home">user area</a> | <a href="/help/">help</a></div><br /></td> </tr> <tr><td colspan="2"><p><img src="/images/eprints/footerline.gif" width="100%" height="4" /></p></td></tr> <tr valign="top"> <td width="68%" class="footer">Authorised by the University Librarian<br /> © University of Tasmania ABN 30 764 374 782<br /> <a href="http://www.utas.edu.au/cricos/">CRICOS Provider Code 00586B</a> | <a href="http://www.utas.edu.au/copyright/copyright_disclaimers.html">Copyright & Disclaimers</a> | <a href="http://www.utas.edu.au/accessibility/index.html">Accessibility</a> | <a href="http://eprints.utas.edu.au/feedback/">Site Feedback</a> </td> <td width="32%"><div align="right"> <p align="right" class="NoPrint"><a href="http://www.utas.edu.au/"><img src="http://www.utas.edu.au/shared/logos/unioftasstrip.gif" alt="University of Tasmania Home Page" width="260" height="16" border="0" align="right" /></a></p> <p align="right" class="NoPrint"><a href="http://www.utas.edu.au/"><br /> </a></p> </div></td> </tr> <tr valign="top"> <td><p> </p></td> <td><div align="right"><span class="NoPrint"><a href="http://www.eprints.org/software/"><img src="/images/eprintslogo.gif" alt="ePrints logo" width="77" height="29" border="0" align="bottom" /></a></span></div></td> </tr> </table> <!-- #EndLibraryItem --> <div align="center"></div></td> </tr> </table> </body> </html>