Pumice clast behaviour in a boiling water context: sedimentological implications

Pumice clasts present in some detritic sedimentary sequences suggest that they have a density exceeding that of water during transport and accumulation. Because these clasts usually have a density that does not exceed 1g/cm3 and float on water, their behaviour suggests a sinking process to enable th...

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Bibliographic Details
Authors: Bargalló, Roger, Enrique Gisbert, Pere, Colombo Piñol, Ferrán
Format: article
Publication Date:2013
Country:España
Institution:Universidad de Huelva (UHU)
Repository:Arias Montano. Repositorio Institucional de la Universidad de Huelva
Language:English
OAI Identifier:oai:ariasmontano.uhu.es:10272/7206
Online Access:http://hdl.handle.net/10272/7206
Access Level:Open access
Keyword:Pumice clast
Pumice conglomerate
Boiling water
Pyroclastic flow
Pumice sunk
Clastos pumíticos
Conglomerado pumítico
Agua hirviendo
Flujo piroclástico
Hundimiento de pumitas
Description
Summary:Pumice clasts present in some detritic sedimentary sequences suggest that they have a density exceeding that of water during transport and accumulation. Because these clasts usually have a density that does not exceed 1g/cm3 and float on water, their behaviour suggests a sinking process to enable them to form part of the sedimentary record.We propose that the most probable mechanism for this is the interaction of pumice clasts at high temperatures with a mass of boiling water. The steam generated would replace the gases in the pores of the pumice by water molecules through micro connections. Subsequent cooling would determine the condensation of the water and the decrease in pressure in the pores. This partial vacuum would result in water absorption, increase in density and in the sinking of the pumice