Here's why:
* Glacial Deposition: As glaciers melt, they release the rocks, sediment, and debris they have been carrying. This material is deposited in a chaotic and unsorted manner, creating a distinctive mix of sizes and types of rock fragments.
* Till: This unsorted material is specifically called till, a glacial deposit that is characterized by its lack of layering and the presence of a wide range of particle sizes.
The process you describe, where dry soil particles are blown away, is called deflation. While deflation can occur in areas where till is deposited, it's not directly related to the glacial deposition process itself. Deflation is a separate wind erosion process that removes fine-grained particles, leaving behind coarser material.
Therefore, the unsorted rock material deposited directly by a melting glacier is called till, and the wind erosion process that removes fine-grained particles is called deflation.
