Rifting occurs when continents stretch apart, creating depressions on the Earth's surface that become filled with magma rising from the melting mantle
Exploring Deep Mantle Heterogeneities via Rift Magma Modeling During Continental Rifting
Rifting occurs when continents stretch apart, creating depressions on the
Earth's surface that become filled with magma rising from the melting mantle.
This process takes millions of years and leads to significant variations in
the chemical composition of the magma, reflecting changes in the conditions
under which the mantle melts.
While a decrease in pressure beneath a thinning lithosphere plays a primary
role in this process, it alone cannot account for the diversity of rift
magmas. In a recent study by Mayle and Harry in 2023, a novel approach was
employed to assess both the quantity and petrological characteristics (such as
mineral composition) of the magmas generated during rifting.
This research involved computational simulations that modeled the evolving
temperature and pressure conditions, considering various mantle source rocks
ranging from water-rich basalts to dry mantle. The authors were able to
calculate the relative amounts and types of magmas produced, closely matching
those observed in real rifts.
These findings shed light on the types of rocks that may have existed beneath
continents undergoing rifting before they started to drift apart. The study by
Mayle and Harry is titled "Syn-rift Magmatism and Sequential Melting of
Fertile Lithologies in the Lithosphere and Asthenosphere" and was published in
the Journal of Geophysical Research: Solid Earth in 2023.
The full citation for the paper is:
Mayle, M., & Harry, D. L. (2023). Syn-rift Magmatism and Sequential
Melting of Fertile Lithologies in the Lithosphere and Asthenosphere. Journal
of Geophysical Research: Solid Earth, 128, e2023JB027072.
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