Sedimentation:
Sedimentation is the process by which particles settle out of a fluid and accumulate as sediment. It involves the deposition of solid particles from a state of suspension or solution in a fluid. Sedimentation occurs in various natural environments such as rivers, lakes, oceans, and even in the atmosphere. Understanding the process of sedimentation is crucial in studying the formation and characteristics of sedimentary rocks.

Transportation:
Transportation is the movement of sediment particles from one place to another by various agents such as wind, water, ice, or gravity. It is an essential process in the formation of sedimentary rocks as it helps in sorting and depositing sediments based on their size, shape, and density. Different agents of transportation have distinct characteristics that affect the type and arrangement of sediments deposited.

Diagenesis:
Diagenesis refers to the physical and chemical changes that occur to sediments after deposition and before they become solid rock. It involves processes such as compaction, cementation, recrystallization, and chemical reactions. Diagenesis is responsible for transforming loose sediment into a cohesive rock. It also plays a significant role in altering the properties and composition of sedimentary rocks over time.

Sedimentation Process:
1. Weathering: The process of breaking down rocks into smaller particles by physical, chemical, or biological means.
2. Erosion: The transportation of weathered materials by agents such as water, wind, ice, or gravity.
3. Deposition: The settling of sediments as agents of transportation lose energy and can no longer carry the particles.
4. Stratification: The layering of sediments based on their size, density, and composition.
5. Lithification: The process of transforming loose sediment into solid rock through compaction and cementation.

Transportation Agents:
1. Water: Sediments are transported by rivers, streams, and ocean currents. Water can carry sediments of various sizes depending on its velocity.
2. Wind: Fine-grained sediments such as silt and clay can be transported by wind and deposited in areas with low wind velocity.
3. Ice: Glaciers transport sediments as they move and deposit them when they melt, forming characteristic landforms.
4. Gravity: Mass movements such as landslides and rockfalls can transport large amounts of sediments downhill.

Diagenesis Processes:
1. Compaction: The weight of overlying sediments squeezes the grains together, reducing pore space and increasing sediment density.
2. Cementation: Minerals dissolved in groundwater can precipitate and fill the pore spaces between sediment grains, binding them together.
3. Recrystallization: The transformation of minerals within the sediment, leading to the growth of new crystals and changes in texture.
4. Chemical Reactions: Various chemical reactions can occur between minerals and fluids, altering the composition and properties of the sediment.

Understanding the processes of sedimentation, transportation, and diagenesis is crucial in deciphering the history and characteristics of sedimentary rocks. These processes interact with each other and contribute to the formation, structure, and composition of sedimentary deposits. By studying these processes, geologists can reconstruct past environments, interpret Earth's history, and analyze the potential for the presence of valuable resources.