What type of rocks were once igneous or sedimentary, but have metamorphosed as a result of intense heat and/or pressure within the Earth's crust?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. Quartzite.
- Quartzite is a compact, hard, non-foliated, medium to coarsely crystalline, and almost mono-mineral metamorphic rock with a granoblastic texture.
- Quartzite is a metamorphic rock made almost entirely of the quartz mineral.
- Quartzite begins its geologic life as sand grains, perhaps on a beach, desert dune, or riverbed.