Gce Model Questions Vol1 2022 Geography Question 6

In Region X three distinct rock units are exposed as follows: - Unit A: A coarse‑grained pink granite that cuts across the other units and contains visible feldspar crystals. - Unit B: A red sandstone with well‑preserved cross‑bedding and fossil shells; it lies beneath Unit C. - Unit C: A dark basaltic lava flow that overlies Unit B and displays columnar jointing. The field observations record that the granite (Unit A) intrudes both the sandstone (Unit B) and the basalt (Unit C). No other structural relationships are noted. Answer the following: (a) Identify the three rock types and briefly describe the geological processes that formed each. (b) Using the principles of superposition, original horizontality and cross‑cutting relationships, determine the relative chronological order of formation of the three units. (c) Discuss two major economic uses of these rocks and two environmental concerns associated with their extraction in the region.