GeoLog

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Imaggeo On Monday: Blue Olivine in an unusual basalt

Imaggeo On Monday: Blue Olivine in an unusual basalt

Blue Olivine set in a matrix of pyroxene, magnetite and plagioclase in a basalt collected by the photographer, Bernardo Cesare, on the shore of the Sea of Galilee, Israel. Polarized light photomicrograph. Crossed polarizers and red tint plate. Width c. 2.7 mm. Who may have been throwing this stone a couple millennia ago?   Description by Bernardo Cesare, after the description on imaggeo.egu.e ...[Read More]

Imaggeo on Mondays: Cooking crystals in the Earth cauldron

Imaggeo on Mondays: Cooking crystals in the Earth cauldron

This picture shows a 30 micrometer thick rock section of a gabbro from the Rum Layered Intrusion (Scotland). Large clinopyroxene crystals are enclosed in a foliated fine grained groundmass of plagioclase and olivine. The clinopyroxene core crystallized at an early stage, at 1160°C. They were partly molten at 1200°C during successive hot magma injections and subsequently recrystallized, enclosing h ...[Read More]