Structural geologists seek to understand how rocks have changed shape, in order to better understand wider processes such as how mountains are formed. Sometimes they use a terminology called ‘Deformation-numbers’ which I will now explain via a series of pretty pictures. Structural geologists spend their day measuring the orientations of things. These can be planar… Continue reading Structural Geology by the Deformation numbers
Cornwall: tin, pasties and the world
The county of Cornwall is like England’s foot, stretching out languorously into the warm waters of the Gulf Stream. Now a relatively poor area, best known for fishing and tourism, it has a proud industrial past based on mining, notably of tin. Once the most important thing about Britain, Cornish tin is now distributed across the world.… Continue reading Cornwall: tin, pasties and the world
The Grampian / Taconic orogeny in Ireland – when arcs attack
Ever since the plate tectonic paradigm-shift of the 1960s, geologists have strived to understand ancient rocks in terms of the movements of plates. The geology of north-western Ireland can be explained by what happened when a subduction zone ran out of oceanic crust back in the Ordovician. Let me take you back to before that… Continue reading The Grampian / Taconic orogeny in Ireland – when arcs attack
Scandinavian crust now in Alaska!
The face of the earth is ever changing. Plate tectonics is slowly but surely rearranging the locations and inter-connections of continents. However knowing this in the abstract doesn’t prepare you for the awed surprise of discovering that a section of crust formed in Scandinavia is now found in Alaska. The evidence for this comes from… Continue reading Scandinavian crust now in Alaska!