News

MSc presentation by Byron Fabian Pilicita Masabanda

19 January 2021

Byron Fabian Pilicita Masabanda from Ecuador, MSc Fellow in Geology at the University of Iceland will give a presentation on his MSc project on Thursday 21 January, 2021 at 10:20.  The presentation will be a part of the UI series "Online Masterday" and will be 15 min long with 5 min allowance for questions.  

The title of the project is:

Hydrothermal alteration in the ASK-57 and ASK-86 exploratory wells at Hoffell/Miðfell within the Tertiary Geitafell volcano

Byron's supervisors are:

Dr Enikö Bali, Associate Professor at the University of Iceland

Dr Guðmundur Heiðar Guðfinnsson, Research Scholar - Associate Research Professor at University of Iceland

The external examiner was Dr Tobias Björn Weisenberger, Geochemist at ISOR

The presentation will be streamed live on:
https://www.youtube.com/watch?v=V6ALXjQS0Uo&feature=youtu.be  

Abstract

The Hoffell/Miðfell area is part of a hydrothermal system located on the south flank of the Tertiary Geitafell volcano. Several wells have been drilled in the area and various studies have been carried out, showing interaction between hot intrusions and meteoric water that led to the development of prograde and retrograde alteration. However, there is a lack of detailed mineral chemistry data from the area, as from most Icelandic geothermal systems. The ASK-57 and ASK-86 core sections show volcanic sequences affected by progressive high-temperature hydrothermal metamorphism that was followed by low-temperature zeolitization after a drop in regional temperatures. These events can be identified from the hydrothermal mineral assemblages formed and precipitated in vesicles, veins and the matrix of the rocks analyzed. Stage I is characterized by the crystallization of fine-grained chlorite interbedded with fine-grained epidote in veins, small vesicles and filling the bottom parts of geopetal structures. Stage II occurred after a progressive temperature increase that formed chlorite + epidote + wairakite + calcite + quartz + albite ± K-feldspar ± actinolite ± clinopyroxene ± magnetite ± ilmenite ± titanite. Stage III occurred after temperature drop and is marked by zeolite mineralization that includes laumontite, yugawaralite, stellerite, stilbite, and chabazite. Altogether 15 different mineral phases were identified, and there are at least three separate temperature-controlled “alteration zones” in the Hoffell/Miðfell core sections.