Radioactive decay provides an internal source of heat for the earth. This helps in the formation of which type of rocks ?

Options

A. Igneous
B. Sedimentary
C. Metamorphic
D. All of the above

Answer

A

Explanation

Igneous means made from fire or heat. Igneous rocks are fromed by the agency of fire out of molten matter. About `50%` of the heat given off by the Earth is generated by the radioactive decay of elements such as uranium and thorium, and their decay products. The most popular model of radioactive heating is based on the bulk silicate Earth (BSE) model, which assumes that radioactive materials, such as uranium and thorium, are found in the Earth's lithosphere and mantle- but not in its iron core. The BSE also says that the abundance of radioactive material can be estimated by studying igneous rocks formed on Earth, as well as the composition of meteorites.