Grain-size distribution of volcaniclastic rocks 2: Characterizing grain size and hydraulic sorting

Abstract

Proussevitch, A.A.. 2015 Grain-size distribution of volcaniclastic rocks 2: Characterizing grain size and hydraulic sorting. Journal of Volcanology and Geothermal Research. 10.1016/j.jvolgeores.2015.05.019 (In Press) Contact NOC NORA team at publications@noc.soton.ac.ukThe NERC and NOC trademarks and logos ('the Trademarks') are registered trademarks of NERC in the UK and other countries, and may not be used without the prior written consent of the Trademark owner. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. ÔØ Å ÒÙ× Ö ÔØ A C C E P T E D M A N U S C R I P T ACCEPTED MANUSCRIPT Highlights:Functional stereology is efficient to interpret sedimentation mechanisms Simple hydraulic sorting ratios allow inference on styles of deposition Transport and deposition mechanisms can be evaluated from pumiceous rocksModes are more adequate than median to characterize sediment grain size Keywords:Stereology; Image analysis; Hydraulic sorting; Hydraulic equivalence, Grain size distribution; Volcaniclastic rock; Clastic rock; Ohanapecosh; Dogashima; Manukau; Sierra La Primavera. sorting ratios can be applied to any type of clastic rocks, and indifferently on consolidated and unconsolidated samples. A C C E P T E D M A N U S C R I P T ACCEPTED MANUSCRIPT

A discriminatory diagram of massive versus stratified deposits based on the sedimentation and bedload transportation rates. Experimental investigation and application to pyroclastic density currents

“…(). The calculation utilizes the concept of hydraulic equivalence, which states that if two components (for example, vesicular glass and crystals) that have different median size, density and shape, coexist in a deposit, it means that they were settling from suspension with the same settling velocity (Jutzeler et al ., ). By using the assumption that sedimentation occurs when the settling velocity approaches current shear velocity (Middleton & Southard, ), the software equates the settling velocity of the two components and solves for the current shear velocity u * , total concentration C tot and Rouse number at maximum suspension capacity Pn susp , with y 0 obtained numerically (Dellino et al ., ).…”

Submarine deposits from pumiceous pyroclastic density currents traveling over water: An outstanding example from offshore Montserrat (IODP 340)

“…Pumice clasts can also be resedimented in fluvial and coastal environments, and eventually enter the ocean as already-waterlogged pumice, or as floating clasts that form pumice rafts (Manville et al, 1998(Manville et al, , 2002Riggs et al, 2001;Kataoka and Nakajo, 2002;Kataoka, 2005;Larsen et al, 2014). Settling through the water column leads to hydraulic sorting (Jutzeler et al, 2015b) of the clasts by their drag (i.e., clast size, density, and shape). Water settling of large volumes of volcanic clasts can form vertical plumes of fine ash (Manville and Wilson, 2004;Jacobs et al, 2015).…”

“…Assuming a bulk dense rock (i.e., glass and crystal) density of 2400 kg/m 3 , the dry bulk density of the vesicular pumice would range 360-840 kg/m 3 (median at 632 kg/m 3 ), and the mean fully waterlogged pumice density would be 1360 kg/m 3 . Image analysis and functional stereology (Jutzeler et al, 2012(Jutzeler et al, , 2015b applied to scanning electron microscope (SEM) images of four representative pumice clasts, and multiple microtomography images (see Meth-ods) reveal three types of pumice vesicularity (Figs. 7 and 8) and a similar range of porosity as that calculated by Archimedes' principle ( Fig.…”

Pumice clasts in cross stratified basalt-dominated sandstones and conglomerates. Characteristics and depositional significance: Huarenchenque Fm (Neuquén, Argentina)

“…The calculation of equivalent diameters of quartz and pumice using different equations (Rubey ,1933;Tourtelot, 1968;Jutzeler et al, 2015) yields a pumice diameter 6 to 10 times greater than those of quartz grains (about 3 to 5 mm).…”