Massive amounts of erupting lava are connected to the destruction of supercontinents and dramatic changes in climate and ecosystems. Such fiery events have produced large igneous provinces throughout Earth’s history. They are often attributed to upwelling of hot, deeply sourced mantle…
Massive amounts of erupting lava are connected to the destruction of supercontinents and dramatic changes in climate and ecosystems. Such fiery events have produced large igneous provinces throughout Earth’s history. They are often attributed to upwelling of hot, deeply sourced mantle material, or “mantle plumes.”
New research from UC Davis and Aarhus University in Denmark shows that high mantle temperatures miles beneath the Earth’s surface are essential for generating such large amounts of magma. In fact, scientists found that a central Iceland volcano that lies directly above the hottest portion of the North Atlantic mantle plume.
The published study will appear in the November issue of the scientific journal Nature Geoscience. The lead authors Charles Lesher, professor of Earth and Planetary Science at UC Davis and Dr Eric Brown, now a post-doctoral scholar at Aarhus University.
“From time to time the Earth’s mantle discharges huge quantities of magma on a scale unlike anything witnessed in historic times,” Lesher said. “These events provide unique windows into the internal working of our planet.”
Based on the volcanic record in and around Iceland over the last 56 million years and numerical modeling, Brown and Lesher show that high mantle temperatures are essential for generating the large magma volumes that gave rise to the North Atlantic large igneous provinces bordering Greenland and northern Europe.
Their findings further substantiate the critical role of mantle plumes in forming large igneous provinces.
“Our work offers new tools to constrain the physical and chemical conditions in the mantle responsible for large igneous provinces,” Brown said. “There’s little doubt that the mantle is composed of different types of chemical compounds, but this is not the dominant factor. Rather, locally high mantle temperatures are the key ingredient.”