Glaciovolcanic Deposits In NE Iceland

• Main Author: Schmidt, Cole
• Format: Text
• Language: unknown
• Published: UWM Digital Commons 2023
• Subjects: glacier; Iceland
• Online Access: https://dc.uwm.edu/uwsurca/2023/poster/136

Glaciovolcanism includes any interactions between magma and glacial ice, but it also encompasses any reactions with water formed by melting ice. Glacio-volcanic deposits capture and preserve evidence of the eruptive environment beneath the glacial ice; therefore, careful observations and analytical work on these deposits allows for reconstruction of previous climatic conditions and paleoenvironments. Additionally, with the rapid change of our current climate, glacial margins and ice sheets have been in consistent retreat. Studies have proven that the retreat of glacial ice sheets has a direct correlation with the frequency of volcanic eruptions. The potential for more intense and frequent eruptions serves one objective of glacio-volcanic studies. Iceland is an ideal location to study glaciovolcanism due to its high latitude and prolific volcanic activity. The focus of this study was three glacio-volcanic edifices called tuyas (Gæsafjöll, Bláfjall, and Burfell) which formed during the Pleistocene. Tuyas are curious flat-topped volcanoes comprised of a base consisting of pillow basalt, overlain by hyaloclastite material, and capped by subaerial lava flows. A product of these volcanic-ice interactions is volcanic glass. The glass forms when hot magma quenches beneath the ice beneath the glacier. The glass either forms rinds on the pillow structures or as small chips in the fragmental hyaloclastite deposits. In the laboratory, fresh glass chips were selected from the pillow and hyaloclastite deposits. The chemistry of the glass chips will be analyzed for major elements and select trace elements by X-ray Fluorescence (XRF), for water and carbon dioxide by Fourier Transform Infrared Spectrometry (FTIR) spectroscopy, and for major elements and sulfur and chlorine by electron microprobe (EMP) analysis. Critically, the volatiles such as water and carbon dioxide allow estimates of the ice thickness at the time of eruption owing to the pressure-dependence of volatile solubility in magmas.