Huge Dike Intrusion in Spain
|Gorgeous Dike Intrusion in Spain.|
Copyright: Miltos Andreadis
One of the most amazing images of a dike you are ever likely to see. This one is exposed in a road cutting on La Gomera, Spain's Canary Islands, high up on the "cumbre" above Vallehermoso. The dike has been intruded into red layered volcanic ashes and as it has melted its way towards the surface (which must have been much higher than the eroded surface we see today) it has simply gobbled up the ash layers, leaving an incredibly clean contact on either side.
The dike is made of basalt and it is about 10m wide. The stone wall marks the edge of the roadway.
A dike is a sheet of rock that formed in a fracture in a pre-existing rock body. Dikes can be either magmatic or sedimentary in origin. Magmatic dikes form when magma intrudes into a crack then crystallizes as a sheet intrusion, either cutting across layers of rock or through an unlayered mass of rock. Clastic dikes are formed when sediment fills a pre-existing crack.