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NDA 2 2024 GAT, question 110

Topic: Geography

Q110

Which one of the following is an example of both an igneous as well as a metamorphic rock ?

  1. (a) Gabbro
  2. (b) Geyserite
  3. (c) GneissoidCorrect answer
  4. (d) Granite

Solution.

Answer: (c) Gneissoid

  1. Gneissoid granite starts as an igneous rock (granite) and is later altered by heat and pressure into a banded, gneiss-like rock.
  2. So it shows both an igneous origin and metamorphic change.
  3. Gabbro and granite are igneous only, and geyserite is a hot-spring deposit.

Trap: Gneissoid describes a banded texture rather than a separate rock type; it is the only option linked to both processes.