Determination of Pre-Eruptive H2o Content in Subduction Zone Magmas: An Example from Taal Caldera Scoria Pyroclastic Flow Deposits, Philippines

 

Ma. Mylene L. Martinez-Villegas and Stanley N. Williams

 

 

 

ABSTRACT

 

Analysis by Secondary Ion Mass Spectrometry (SIMS) of the melt inclusions found in plagioclase, pyroxene and olivine host minerals of clasts from the 5,600 years BP Taal Caldera scoria pyroclastic flow (SPF) deposits reveals up to 3.9 wt% of pre-eruptive H2O in the melts. The water content is comparable to that of in-melt inclusions from other mafic-intermediate explosive eruptions and probably contributed to the volume and explosive nature of the SPF eruptions.

 

 

 

 

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