Google the words metamorphism and etymology and you’ll likely find a link to a 16th Century definition of metamorphism: “change of form or shape, especially by witchcraft”. Gneiss formation by spells is not a popular hypothesis these days, but many a student has been tempted to regard thermobarometry as a form of witchcraft. In my… Continue reading Thermobarometry: quantifying metamorphic conditions
A trip to the museum
On the last summer’s day of the year, I made a visit to the Oxford University Museum of Natural History, which is a rather lovely place to be. The building is lovely. A classic example of Victorian Gothic Revival architecture, built in the 1850s. Like most of Oxford, it is built of local Cotswold stone,… Continue reading A trip to the museum
Metamorphism: Pressure-Temperature-time paths
Pressure-Temperature-time paths This post is in the middle of a series on metamorphism. Concepts such as metamorphic facies or grade all allow us to link a metamorphic rock to a particular set of conditions, under which it was metamorphosed. This is a simplification, of course. Hold a piece of schist in your hand: we know… Continue reading Metamorphism: Pressure-Temperature-time paths
Metamorphism: grade, zones, index minerals, and whisky
This post is second in a series of posts about metamorphism. Metamorphic grade, zones and index minerals Science is based on a solid understanding of underlying physical principles. Although I have chickened-out of the detail, everything I mention in the previous post is based on a solid understanding of chemistry and physics. The knowledge we… Continue reading Metamorphism: grade, zones, index minerals, and whisky