Social Science (087) — AI-generated practice question

Gypsum & Potash Salt (Evaporation Process):
These minerals are formed as a result of evaporation in arid regions. When water bodies in dry areas evaporate, dissolved salts and minerals are left behind, accumulating and concentrating in horizontal strata to form beds or layers of gypsum, potash salt, and sodium salt.

Coal (Heat & Pressure Process):
Coal is formed by the compression of plant material over millions of years in valley basins (e.g., swamps). Buried plant matter is subjected to great heat and pressure over long periods, which concentrates it into coal deposits found in sedimentary rock strata.

Thus, evaporation forms one group, while heat and pressure over geological time forms the other.

Source: Chapter 5, Mode of Occurrence of Minerals

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• The examiner wants two clearly contrasted processes — evaporation (for gypsum/potash) vs. heat and pressure/compression (for coal).
• Both are described under point (ii) of sedimentary rock minerals in the textbook — keep answers grounded there.
• Use keywords: evaporation, arid regions, beds/layers, compression, heat and pressure, valley basins — these fetch marks.
• Avoid mixing up the two groups; the contrast is the core of the question.