Vikrahraun-the 1961 basaltic lava flow eruption at Askja, Iceland: morphology, geochemistry, and planetary analogs.

ABSTRACT: We examine the morphology and chemistry of the Vikrahraun basaltic eruption emplaced at Askja Volcano, Iceland, from Oct. 26-Dec. 17, 1961. The eruption had three eruptive events, initiating with a'a and followed by alternating a'a and pahoehoe lava flow emplacement. We determine that while the eruption is chemically homogenous (Fe/Mg = 1.9-2.2, 47-52 wt.% SiO2), it demonstrates transitions from high to low viscosity lava flow morphologies. A'a flows have a total crystallinity (phenocryst and microlite abundance by area) ranging from 85-100%, which increases by 1% per km from the vents, while pahoehoe flows range from 55-86% and increase at a higher rate of 5% per km. Vesicularity systematically decreases with distance from the vent by 3% per km. Pahoehoe and vent samples have calculated t

SUBMITTER: Blasizzo AY 

PROVIDER: S-EPMC9653356 | biostudies-literature | 2022

REPOSITORIES: biostudies-literature