Author Archives: Metageologist

Into the Third Dimension: using Google Maps to know what’s underground

Much of the earth’s surface is covered by sedimentary rocks. These form as sediment settles on the surface. As the types of sediment change – sand to mud to sand again – different layers are formed, some hard some soft. The … Continue reading

Categories: Great Geology in Google earth, tectonics

Looking from the sky at diamonds

When a geologist looks at Google Maps images, we usually filter out any human activity. But in the case of mines, that would be a mistake – the holes humans dig can tell us about the geology. What’s this? A big … Continue reading

Categories: diamonds, Great Geology in Google earth

Great Geology in Google Maps: mapping from above

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 … Continue reading

Categories: Great Geology in Google earth, sediments

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 … Continue reading

Categories: Deep earth