Ring dike
Encyclopedia
A ring dike or ring dyke in geology
refers to an intrusive igneous body. Their chemistry, petrology
and field appearance precisely match those of dikes
or sill
, but their concentric or radial geometric distribution around a centre of volcanic activity indicates their subvolcanic origins.
Geology
Geology is the science comprising the study of solid Earth, the rocks of which it is composed, and the processes by which it evolves. Geology gives insight into the history of the Earth, as it provides the primary evidence for plate tectonics, the evolutionary history of life, and past climates...
refers to an intrusive igneous body. Their chemistry, petrology
Petrology
Petrology is the branch of geology that studies rocks, and the conditions in which rocks form....
and field appearance precisely match those of dikes
Dike (geology)
A dike or dyke in geology is a type of sheet intrusion referring to any geologic body that cuts discordantly across* planar wall rock structures, such as bedding or foliation...
or sill
Sill (geology)
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 even along the direction of foliation in metamorphic rock. The term sill is synonymous with concordant intrusive sheet...
, but their concentric or radial geometric distribution around a centre of volcanic activity indicates their subvolcanic origins.
Notable examples
- One of the best exposed and studied ring dikes is the Loch Bà ring dike, Isle of MullIsle of MullThe Isle of Mull or simply Mull is the second largest island of the Inner Hebrides, off the west coast of Scotland in the council area of Argyll and Bute....
, ScotlandScotlandScotland is a country that is part of the United Kingdom. Occupying the northern third of the island of Great Britain, it shares a border with England to the south and is bounded by the North Sea to the east, the Atlantic Ocean to the north and west, and the North Channel and Irish Sea to the... - The ring dikes in the Pawtuckaway State ParkPawtuckaway State ParkPawtuckaway State Park is a preserve in New Hampshire, United States. It is one of the largest state parks in southeastern New Hampshire and is named for Pawtuckaway Lake and the Pawtuckaway Mountains...
and the Ossipee MountainsOssipee MountainsThe Ossipee Mountains are located just south of the White Mountains of New Hampshire, United States. Mount Shaw, at , is the highest point in the range.-Geology and physiography:...
of New HampshireNew HampshireNew Hampshire is a state in the New England region of the northeastern United States of America. The state was named after the southern English county of Hampshire. It is bordered by Massachusetts to the south, Vermont to the west, Maine and the Atlantic Ocean to the east, and the Canadian... - The Pilanesberg Game Reserve in the North West Province of South AfricaSouth AfricaThe Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
See also
- BatholithBatholithA batholith is a large emplacement of igneous intrusive rock that forms from cooled magma deep in the Earth's crust...
- Fissure ventFissure ventA fissure vent, also known as a volcanic fissure or simply fissure, is a linear volcanic vent through which lava erupts, usually without any explosive activity. The vent is usually a few meters wide and may be many kilometers long. Fissure vents can cause large flood basalts and lava channels...
- LaccolithLaccolithA laccolith is a sheet intrusion that has been injected between two layers of sedimentary rock. The pressure of the magma is high enough that the overlying strata are forced upward, giving the laccolith a dome or mushroom-like form with a generally planar base.Laccoliths tend to form at relatively...
- RunamoRunamoRunamo is a cracked dolerite dike that was for centuries held to be a runic inscription and gave rise to a famous scholarly controversy in the 19th century. It is located 2.7 km from the church of Bräkne-Hoby in Blekinge, Sweden...
, formerly interpreted as a runic inscription.