Question

What type of rock is formed from molten magma?
A) Sedimentary
B) Igneous
C) Metamorphic
D) None of these

Answer 1

Hint: It is also called magmatic rock and is one of the three main rock types. It is available in a wide range of geological settings.

Complete answer:
Igneous rock or magmatic rock is one of the three principle rock types, the others being sedimentary and metamorphic. Igneous rock is shaped through the cooling and cementing of magma. The magma can be derived from incomplete melts of existing rocks in either a planet's mantle or crust. Commonly, the dissolving is brought about by at least one of three cycles: an increase in temperature, a decline in pressure, or an adjustment in synthesis.

Hardening into rock happens either underneath the surface as nosy rocks or on a superficial level as extrusive rocks. Igneous rock may shape with crystallization to frame granular, translucent rocks, or without crystallization to frame characteristic glasses. Igneous rocks occur in a wide scope of geological settings: shields, stages, orogens, bowls, huge molten areas, expanded hull, and maritime outside.

Igneous rocks are likewise geologically significant on the grounds that:
I) Their absolute ages can be acquired from different types of radiometric dating and can be contrasted with nearby land layers, in this manner allowing adjustment of the geographical time scale;.
II) In some extraordinary conditions they have significant mineral deposits (ores). For instance, tungsten, tin, and uranium are ordinarily connected with stones and diorites, though ores of chromium and platinum are normally connected with gabbros.

Hence the correct answer is option ‘B’.

Note: Igneous rocks are about 15% of the Earth's present land surface. A wide portion of the Earth's maritime covering is made of igneous rock. Igneous rock is also formed when magma cools and crystallises into a rock formation.