The correct option is 1 and 2 only.
Explanation
Beaches are depositional landforms found along coastlines. They are formed by the accumulation of loose sediments, such as sand, gravel, and pebbles, primarily through the action of waves and currents.
Statement-wise Analysis:
- Statement 1 is Correct: Beaches are characteristic features of shorelines dominated by deposition. While they can occur as isolated patches along rugged, erosional shores, extensive beaches are formed where the accumulation of sediment exceeds the rate of erosion.
- Statement 2 is Correct: The primary source of sediment for most beaches is terrestrial. Streams and rivers transport sediments from the land to the ocean, where waves redistribute them along the shore. Sediments also originate from the erosion of coastal cliffs.
- Statement 3 is Incorrect: Beaches are temporary and dynamic features, not permanent ones. Their profile and composition change significantly with seasons. For example, high-energy storm waves in winter often erode sand, leaving behind coarser pebbles, while calmer summer waves deposit sand back onto the beach.
Key Takeaway:
Beaches are dynamic depositional landforms formed primarily from land-derived sediments transported by rivers; they undergo significant seasonal changes due to varying wave energy.