Table of Contents
Is a batholith intrusive or extrusive?
A batholith (from Ancient Greek bathos ‘depth’, and lithos ‘rock’) is a large mass of intrusive igneous rock (also called plutonic rock), larger than 100 km2 (40 sq mi) in area, that forms from cooled magma deep in Earth’s crust.
Are dikes concordant and sills are discordant?
A) solidify above the surface of the ground AND form by crystallization of magmas intruded into surrounding rocks. Mafic magma is silica poor and may be derived from melting of Earth’s upper mantle. True. Dikes are concordant and sills are discordant.
Which one is a concordant igneous body?
Laccoliths
Laccoliths: Laccoliths are concordant igneous bodies with their lower surface flat and upper surface arched in the form of dome (Fig. 8) such bodies are naturally formed due to the accumulation of viscous magma underneath the rocks occurring upon the surface. Laccoliths may have dykes or sill acting as their feeders.
What is the difference between a batholith and Laccolith?
A large mass of igneous rock forms a batholith, while laccolith is sheet-like intrusions injected within the layers of sedimentary rocks. The batholith is a large irregular mass of intrusive igneous rocks that forces themselves in surrounding strata, and laccolith is a mass of igneous or volcanic rock within strata.
Is igneous intrusive?
Intrusive, or plutonic, igneous rock forms when magma is trapped deep inside the Earth. Intrusive rocks have a coarse grained texture. Extrusive Igneous Rocks: Extrusive, or volcanic, igneous rock is produced when magma exits and cools above (or very near) the Earth’s surface.
Which of the following is a tabular discordant and intrusive body?
Dikes
Dikes. Dikes are tabular discordant intrusions, taking the form of sheets that cut across existing rock beds.
Why is a dike considered a discordant pluton?
A body of intrusive igneous rock which crystallizes from magma cooling underneath the surface of the Earth is called a pluton. If it runs parallel to rock layers, it is called a sill. A sill is concordant with existing layering, and a dike is discordant.
What batholith means?
Definition: Despite sounding like something out of Harry Potter, a batholith is a type of igneous rock that forms when magma rises into the earth’s crust, but does not erupt onto the surface.
Is a concordant body?
It is a concordant body, with flat bottom and convex upward. It is dome or mushroom shaped….
| Intrusion in Unfolded Region | Intrusion in Folded Region | |
|---|---|---|
| Concordant Forms | Sill Laccoliths Lopoliths | Phacolith Concordant Batholiths |
What are concordant bodies?
[kən ′kȯrd·ənt ¦bäd·ē] (geology) An intrusive igneous body whose contacts are parallel to the bedding of the country rock. Also known as concordant injection; concordant pluton.
What laccolith means?
laccolith, in geology, any of a type of igneous intrusion that has split apart two strata, resulting in a domelike structure; the floor of the structure is usually horizontal.
Is obsidian extrusive or intrusive?
Obsidian is an “extrusive” rock, which means it is made from magma that erupted out of a volcano. If it was an igneous rock that formed from magma underground and did not erupt, it would have been called an “intrusive” rock.