What is a dyke?
Q: What is a dyke?
A: A dyke is a geologic body that is produced when later molten lava pushes up between older rock layers, creating vertical rock between older layers of rock.
Q: What types of rock can dykes cut across?
A: Dykes can cut across flat wall rock structures, such as bedding, and massive rock formations, usually igneous in origin.
Q: How are dykes formed?
A: Dykes can be either pushed in between (intrusive) or laid down (sedimentary) in origin. The most usual thing that happens is that later volcanic activity pushes lava through strata which were laid down earlier in a sedimentary fashion, or through earlier igneous rocks.
Q: Where can dyke swarms be found?
A: Dyke swarms can be found on the Isle of Arran and on other planets.
Q: What is breccia?
A: Breccia is broken rocks that can fill in gaps caused by underwater earthquakes.
Q: What is the difference between a dyke and a sill?
A: A dyke is a vertical intrusion, while a sill is a horizontal intrusion. Sills are formed when later rock is formed between older layers, not through them.
Q: What is the significance of dykes in geology?
A: Dykes are common and almost universal in the older Palaeozoic rocks, and they can provide important clues about the geologic history of a particular area.
