The correct option is 2 and 3 only.
Explanation
Weathering is the mechanical disintegration and chemical decomposition of rocks in situ due to the action of various elements of weather and climate. It is a fundamental exogenic process that prepares rock materials for transport and soil formation.
Statement-wise Analysis:
- Statement 1 is Incorrect. Weathering is the primary process responsible for the breakdown of bedrock into smaller fragments and mineral particles. This loose layer of material covering the solid rock is called regolith. Soil is subsequently formed through the biological and chemical modification of this regolith. Therefore, weathering facilitates, rather than hinders, the formation of regolith and soils.
- Statement 2 is Correct. Weathering weakens rock structures and produces loose materials. This prepares the ground for mass wasting (movement of material down a slope under gravity) and erosion (transport of material by agents like water, wind, or ice). Without the initial breakdown caused by weathering, mass wasting and erosion would be significantly difficult or impossible on massive, hard rocks.
- Statement 3 is Correct. Weathering aids in the enrichment of certain valuable ores. Through chemical weathering and leaching, soluble components of the rock are removed, leaving behind a residual concentration of insoluble minerals. This process is critical for the formation of economically viable deposits of minerals such as iron, manganese, aluminum (bauxite), and copper.
Key Takeaway:
Weathering is an in-situ process that is essential for soil formation, facilitates erosion and mass wasting, and leads to the concentration of valuable mineral ores through the leaching of impurities.