Fossil bubble in porphyritic basaltic pyroclasts produced by small and large strombolian eruption at Pacaya, Guatemala


Autoria(s): Cigala, Valeria
Data(s)

01/01/2013

Resumo

We investigate compositionally monotonous, but energetically diverse, tephra samples from Pacaya to see if fossil bubbles in pyroclasts could reflect eruptive style. Bubble size distributions (BSD) were determined for four ash to lapilli size tephra samples using an adapted version of stereology conversion by Sahagian and Proussevitch (1998). Eruptions range from very weak to very energetic. Hundreds of ESEM BSEs images were processed throughout ImageJ software for a robust and statistically correct data set of vesicles (minimum 700 bubbles per sample). Qualitative textural analysis and major element chemical compositions were also executed. There is higher vesicularity for explosive pyroclasts and an inverse correlation between bubble number density (NV) and explosivity.

Formato

application/pdf

Identificador

http://digitalcommons.mtu.edu/etd-restricted/163

http://digitalcommons.mtu.edu/cgi/viewcontent.cgi?article=1161&context=etd-restricted

Publicador

Digital Commons @ Michigan Tech

Fonte

Dissertations, Master's Theses and Master's Reports - Restricted

Palavras-Chave #ash #bubbles #Pacaya #strombolian #volcanoes #Geology
Tipo

text