Erosion and Weathering:
* Weathering: This is the process of breaking down rock into smaller pieces. It can be physical (like freezing water expanding in cracks), chemical (acid rain dissolving rock), or biological (plant roots growing through rock).
* Erosion: This is the process of moving weathered rock and sediment from one place to another. Wind, water, and ice are major agents of erosion. Rivers carve canyons, glaciers grind down mountains, and wind carries sand and dust.
Sedimentation and Deposition:
* Sediment Transport: The eroded material, now called sediment, is transported by wind, water, or ice.
* Deposition: Eventually, the sediment is deposited in a new location, often in a lower elevation. This can be in valleys, oceans, lakes, or deserts.
Impact on the Crust:
* Crustal Thinning: As mountains erode, the crust is literally thinned and lowered. The material that was once part of the mountain is now scattered elsewhere.
* Isostatic Adjustment: The Earth's crust is in a state of balance. As the mountains erode and become lighter, the crust will slowly rise upward (isostatic rebound) to compensate for the lost mass.
* Formation of New Landforms: Erosion and deposition create new landforms. Sediment deposited in valleys can form fertile plains. Rivers carve out canyons and deltas. Deposition in the ocean can build up land masses over time.
A Continuous Cycle:
This process of erosion and deposition is a continuous cycle. It's a slow process, taking millions of years, but over time it dramatically alters the Earth's surface. The very mountains that stand tall today will eventually be worn down, their material forming new landforms in other locations.
