What does dyke mean in geology?
What does dyke mean in geology?
A dike is a barrier used to regulate or hold back water from a river, lake, or even the ocean. In geology, a dike is a large slab of rock that cuts through another type of rock.
How a dyke is formed?
When molten magma flows upward through near-vertical cracks (faults or joints) toward the surface and cools, dykes are formed. Dykes are sheet-like igneous intrusions that cut across any layers in the rock they intrude.
Is a dike intrusive or extrusive?
Dikes. A dike is an intrusive rock that generally occupies a discordant, or crossâcutting, crack or fracture that crosses the trend of layering in the country rock.
What is an example of a dike?
Ring dikes are intrusive igneous sheets that are circular, oval or arcuate in overall trend. The Ossipee Mountains of New Hampshire and Pilanesberg Mountains of South Africa are two examples of ring dikes. In both of these instances, the minerals in the dike were harder than the rock that they intruded into.
What is dyke in igneous rock?
dike, also called dyke or geological dike, in geology, tabular or sheetlike igneous body that is often oriented vertically or steeply inclined to the bedding of preexisting intruded rocks; similar bodies oriented parallel to the bedding of the enclosing rocks are called sills.
Is dyke a geological structure?
A dyke (or dike) in geology is a type of later vertical rock between older layers of rock. Technically, it is any geologic body which cuts across: a) flat wall rock structures, such as bedding. b) massive rock formations, usually igneous in origin.
What is a dike and sill?
In geology, a sill is a tabular sheet intrusion that has intruded between older layers of sedimentary rock, beds of volcanic lava or tuff, or along the direction of foliation in metamorphic rock. In contrast, a dike is a discordant intrusive sheet, which does cut across older rocks.
Is dike concordant or discordant?
A sill is concordant with existing layering, and a dike is discordant. If the country rock has no bedding or foliation, then any tabular body within it is a dike.
What is a dike eruption?
Dikes are tabular or sheet-like bodies of magma that cut through and across the layering of adjacent rocks. They form when magma rises into an existing fracture, or creates a new crack by forcing its way through existing rock, and then solidifies.
What is sill and dyke?
What is a sea dyke?
Definition of a Sea-dike: An artificial earthen wall, often meant to prevent flooding of the hinterland. Like revetments but without, or hardly any, beach in front of the structure.
