magma – Geobites

August 10, 2022August 10, 2022

Understanding highly explosive basaltic eruptions using simulations

Featured image: A fissure cone of Kīlauea (Hawaii) erupting during the 2018 eruptive episode. via Wikimedia commons (Public domain)

Paper: Role of volatiles in highly explosive basaltic eruptions.

Authors: Giuseppe La Spina, Fabio Arzilli, Mike R. Burton, Margherita Polacci, Amanda B. Clarke

When we think of Hawaii or Iceland, the first thing that comes to mind is volcanoes. Lava fountains spew out basaltic lava, which silently meanders its way to the ocean. The notion that basaltic eruptions are always less explosive compared to other types like rhyolitic and andesitic eruptions is not entirely true. For example, Mount Etna in Italy has produced highly explosive basaltic eruptions such as the 122 BCE Plinian Eruption and another in 1669. Because highly explosive basaltic eruptions are not very common, they’re not fully understood leaving scientists wondering “What could be the reason behind this erratic behaviour?”

March 27, 2021March 27, 2021

What Lies Beneath: Tracing Magma Interactions Within Earth’s Crust

Featured Image: Yosemite National Park, California, USA by Thomas H. from Pixabay

Paper: Feldspar recycling across magma mush bodies during the voluminous Half Dome and Cathedral Peak stages of the Tuolumne intrusive complex, Yosemite National Park, California, USA

Authors: Louis F. Oppenheim, Valbone Memeti, Calvin G. Barnes, Melissa Chambers, Joachim Krause, and Rosario Esposito

Earth’s landscapes provide evidence of the geological processes which have shaped it over the past 4 billion years. The Earth’s crust, our planet’s outermost layer, preserves an extensive record of these processes. Within the crust igneous rocks which were once molten at depth and fed active volcanic eruptions, preserve evidence of the inner workings of volcanoes. These inner workings or “magmatic plumbing systems” are the focus of recent work by Oppenheim et al. (2021). In this work, Oppenheim and co-authors studied the crystal record of fossilized plumbing systems in order to provide new insights into the storage conditions and transport mechanisms of magma within Earths’ crust.

January 25, 2021January 25, 2021

Cooking up crystals in record time

Featured image: Example of the rock type Pegmatite. Here, crystals of the mineral tourmaline (light-dark green color), and crystals of the mineral lepidolite (pink-purple color) can be seen, sourced from Wikipedia. This file is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license.

Paper: Episodes of fast crystal growth in pegmatites

Authors: Patrick R. Phelps, Cin-Ty A. Lee, Douglas M. Morton

Anyone who has ever wandered along a pebble-ridden beach or a mountainous trail has likely picked up a rock or two, and maybe these rocks contained an array of different crystals (see image above). Perhaps these rocks then skipped along the surface of a still lake, or made their way into the pockets of a snack-ridden backpack, either to never be seen again or to be added to an ever-growing rock collection. Yet, these little pieces of Earth’s history have the potential to do so much more. With the right tools, the crystals within these rocks can be used to inform us of the geological processes that have shaped our planet Earth.

August 6, 2020August 6, 2020

How do you break up a continent?

Featured image: Lake Malawi, as seen from space. Image courtesy of ESA/MERIS, CC-BY-SA IGO.

Paper: Preferential localized thinning of lithospheric mantle in the melt-poor Malawi Rift
Authors: E. Hopper, J. B. Gaherty, D. J. Shillington, N. J. Accardo, A. A. Nyblade, B. K. Holtzman, C. Havlin, C. A. Scholz, P. R. N. Chindandali, R. W. Ferdinand, G. D. Mulibo, G. Mbogoni

Continental rifting, where one landmass slowly breaks apart into two pieces separated by a brand new ocean basin, is a fundamental part of plate tectonics. But it presents an apparent paradox: the tectonic forces pulling on the plates are thought to be much too weak to break the strong rocks of the continents.

July 16, 2020December 12, 2020

Tiny but Mighty! Nanosized Drivers of Explosive Volcanism

Paper: Can nanolites enhance eruption explosivity?

Authors: F. Cáceres, F. B. Wadsworth, B. Scheu, M. Colombier, C. Madonna, C. Cimarelli, K-U. Hess, M. Kaliwoda, B. Ruthensteiner, D. B. Dingwell

Explosive volcanic eruptions have punctuated our planet’s geological record for millions of years. The explosive nature of these eruptions can lead to thousands of cubic kilometers (that’s a billion Olympic swimming pools) of material travelling hundreds of miles across our landscapes and into our atmosphere. Approximately 630,000 years ago, the most recent eruption from the Yellowstone volcanic center sent ash and dust from Wyoming to southern Texas, USA. More recently, the 1815 eruption of Mt. Tambora, Indonesia, led to 1816 being historically known as the “Year Without a Summer”. The “Year without a summer” was started when volcanic materials entered the atmosphere and induced a volcanic winter, which led to extreme weather, agricultural stresses, and food shortages across the globe.