1. Weathering and Erosion of Granite:
* Physical Weathering: Granite, exposed on mountain tops, is constantly bombarded by the elements. Wind, rain, ice, and temperature changes break down the granite into smaller fragments.
* Chemical Weathering: Rainwater, slightly acidic due to dissolved carbon dioxide, can react with the minerals in granite, further breaking it down.
* Erosion: Wind, water, and ice transport these broken-down granite fragments downhill.
2. Deposition and Formation of Sandstone:
* Sedimentation: The transported granite fragments, now sand-sized particles, are deposited in basins, valleys, or along coastlines.
* Compaction: As more sediment accumulates, the weight of the overlying layers compresses the sand grains together, squeezing out water.
* Cementation: Dissolved minerals in groundwater precipitate between the sand grains, acting like glue, binding the sand together to form sandstone.
3. Metamorphism into Quartzite:
* Burial and Heat: Over time, the sandstone layers can be buried deeper and deeper, experiencing increasing pressure and heat.
* Recrystallization: Under these conditions, the quartz grains in the sandstone start to recrystallize, forming larger, interlocking crystals.
* Formation of Quartzite: The process of recrystallization transforms the sandstone into quartzite, a hard, metamorphic rock with a distinctive granular texture.
Important Note: While the process described above outlines the general sequence of events, it's important to understand that these changes take place over millions of years. The specific conditions and factors involved in each step can vary greatly.
