3D model reveals new information about iconic volcano

The volcano on the Scottish peninsula Ardnamurchan is a popular place for the study of rocks and structures in the core of a volcano. Geology students read about it in text books and geologists have been certain that the Ardnamurchan volcano has three successive magma chambers. However, an international group of researchers, lead from Uppsala University, Sweden, has now showed that the volcano only has one single magma chamber.

3D model of the Ardnamurchan igneous complex: a) E-W cross-section view. d) Map view. e) Oblique view from NW. c) W-E perspective view from below the Earth's surface. e) Map view. [Credit: Scientific Reports, doi:10.1038/srep02891]

The 58 million year old Ardnamurchan volcano is an iconic site for the study of rocks and structures in the core of a volcano, which is why thousands of geology students from all over the world visit Ardnamurchan every year. Since the early days of modern geology the Ardnamurchan volcano is believed to have had three successive magma chambers (or centres) that fed hundreds of thin arcuate basalt intrusions, so-called cone sheets, that are exposed all over the peninsula.

The researchers from the universities of Uppsala (Sweden), Quebec (Canada), Durham and St. Andrews (UK), challenges the 3-centre concept using a 3D model of the subsurface beneath today’s land surface. According to this model, the Ardnamurchan volcano was underlain by a single but elongate magma chamber.

Studying extinct volcanoes is a way for geologists to understand the interior of volcanic edifices and to gain knowledge on the processes that occur within active volcanoes today. It is therefore that the volcanic centres of western Scotland and northeastern Ireland were intensely studied by British geologists in the late 19th and early 20th century. It was in these eroded volcanoes that the foundation for modern volcanology was laid. Ardnamurchan in particular has an iconic status among geologists everywhere in the world.