The correct option is 2 only
Explanation
Weathering plays a significant role in the formation and concentration of certain mineral deposits. This process, often termed "enrichment," occurs when weathering removes soluble rock constituents, leaving behind a residual mass with a higher concentration of valuable minerals.
Statement-wise Analysis:
- Statement 1 is Incorrect: The process of enrichment involves the leaching or removal of waste materials (silica or other soluble components) from the parent rock. This leaves behind a residue that is enriched in valuable materials such as aluminium (bauxite), iron, or manganese.
- Statement 2 is Correct: Enrichment leads to the concentration of the remaining valuable materials, not their dispersion. As the bulk of the waste rock is removed, the proportion of the valuable mineral in the remaining soil or rock increases significantly.
- Statement 3 is Incorrect: Weathering makes the exploitation of valuable materials economically viable. Without this natural concentration process, the grade of the ore in the original rock might be too low to mine profitably. The enrichment process upgrades the ore to a level where extraction becomes commercially feasible.
Key Takeaway:
Enrichment weathering is a critical geological process that concentrates ores like bauxite and hematite by removing impurities, thereby transforming low-grade rocks into economically mineable deposits.