In most cases, geological maps are made by piecing together observations of hundreds of individual outcrops. Boundaries between types of rock are covered in grass and sheep and have to be traced on the map later as a line between rock outcrops, like a inverted game of dot-to-dot. In areas like Himalayas the same boundaries may be visible in… Continue reading Great Geology in Google Maps: mapping from above
Hot spot volcanoes: no plumes required?
It’s a simple and well-known picture. Volcanoes form either at plate boundaries due to subduction or inside plates due to mantle plumes. Invoking plumes – columns of hot rock rising from deep in the mantle – is an awfully useful way of explaining oddly-placed volcanoes, both ancient and modern. Too useful, many people think. The concept has been… Continue reading Hot spot volcanoes: no plumes required?
Great Geology in Google Maps: dunes
Google Maps is a great resource, particularly in satellite view. My favourite way to enjoy it is via the Chrome extension “Earth View from Google Maps“. This pops up a gorgeous image in every new tab. Many show human landscapes, but every now and then one appears that catches this geologist’s eye. This post is the… Continue reading Great Geology in Google Maps: dunes
Tasting the earth: mantle geochemistry
If seismologists listen to the earth then geochemists taste it. Like experts blind-tasting a glass of wine and recognising where it came from, geochemists studying the deep earth aim to find out where a particular liquid came from. Their liquid – basaltic magma formed from melting of the mantle rocks – is now solid, so ‘tasting it’ involves dissolving… Continue reading Tasting the earth: mantle geochemistry