High Temperature Volcanism on Earth - Michael Lesher (SETI Talks)
Δημοσιεύτηκε στις 22 Ιαν 2016
Komatiites
are magnesium-rich magmas characterized by very high temperature (up to
1640°C vs. ~1200°C for modern basalts), very low viscosity (0.1-1
Pa·s), and a very large interval (460-160°C) between liquidus and
solidus. As a consequence, they formed highly mobile flows capable of
flowing long distances over gentle slopes that - if channelized -
thermally and thermomechanically eroded wallrocks and substrates. This
led to the formation of some of the world’s richest
nickel-copper-platinum group element deposits. The most magnesian
examples formed only the Archean, marking a fundamentally different
thermal structure in the Earth’s mantle prior to 2.5 Ga.
Dr.
Lesher is a world renowned expert in komatiites and he will discuss how
they can help shine help a light on the Early Earth in the remote past.
are magnesium-rich magmas characterized by very high temperature (up to
1640°C vs. ~1200°C for modern basalts), very low viscosity (0.1-1
Pa·s), and a very large interval (460-160°C) between liquidus and
solidus. As a consequence, they formed highly mobile flows capable of
flowing long distances over gentle slopes that - if channelized -
thermally and thermomechanically eroded wallrocks and substrates. This
led to the formation of some of the world’s richest
nickel-copper-platinum group element deposits. The most magnesian
examples formed only the Archean, marking a fundamentally different
thermal structure in the Earth’s mantle prior to 2.5 Ga.
Dr.
Lesher is a world renowned expert in komatiites and he will discuss how
they can help shine help a light on the Early Earth in the remote past.
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