There is a rock. You know nothing about it. Theoretically, what other kind of rock could it form?

Question

There is a rock. You know nothing about it. Theoretically, what other kind of rock could it form? Choose all that apply!



A. Sedimentary rock

B. Igneous rock

C. Metamorphic rock

D. Not enough information to answer this question

Answer 1

Sedimentary rocks are formed when weathered (chemically or mechanically) and eroded rocks/minerals are deposited and compacted/cemented. They can form clastic, biogenic, or chemically precipitated sedimentary rocks. Clastic rocks are made up of weathered fragments of preexisting rock cemented together by dissolved minerals or clay. Biogenic rocks are the result of living organisms and are primarily composed of their compacted remains. Chemically precipitated rocks form when ions dissolved in water are precipitated.

Igneous rocks are formed when molten rock cools and solidifies. Preexisting rocks can be dragged downwards due to movements in the Earth's crust. If temperature rise high enough, those rocks can melt and form magma. If magma is expelled to the surface it will harden and become igneous.

Metamorphic rock can be formed when an initial solid rock, or protolith, is subjected to high heat, pressure, or both. They form when the composition (types of minerals) and/or texture (size/shape/arrangement of mineral grains and crystals) of the protolith changes without melting and forming molten rock.

Nothing is known about the rock in its current state, and the question is what other kind of rock could it form (not what rock it is currently). Thus, the answer should be A, B, and C. Any given rock type can become any other rock type for the reasons outlined above.