Which transformation requires a complete meltdown of the rock into magma?
2 answers:
Igneous rocks are formed by the cooling of the magma.
Sedimentary rocks are formed by weathering and erosion of igneous rocks and then consolidation of the sediments.
Metamorphic rocks are formed when igneous or sedimentary rocks are subjected to heat and pressure.
The metamorphic rocks melts and forms magma which in turn cools down to form igneous rocks.
Similarly, sedimentary rocks melt down and forms magma which cools down to form igneous rocks.
So, the igneous rock is formed by cooling of magma, which is in turn formed from sedimentary and metamorphic rocks.
Of the given options only one option has the resulting rock as igneous.
Hence the answer is
sedimentary rock to igneous rock
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