Which sequence correctly describes the formation of clastic sedimentary rocks?

Which sequence correctly describes the formation of clastic sedimentary rocks?

• A. Weathering, Transportation, Deposition, Lithification
• B. Weathering, Deposition, Transportation, Lithification
• C. Transportation, Weathering, Lithification, Deposition
• D. Deposition, Lithification, Weathering, Transportation

Answer: (A)

The sequence of processes that turn weathered material into solid clastic rock goes in this order: weathering breaks down rocks into sediment; transportation moves those particles away from their source; deposition is where the sediment settles and accumulates; and lithification folds the accumulated sediment into solid rock through compaction and cementation. This order matters because you can’t lithify something that hasn’t been deposited, and you can’t deposit material that hasn’t been transported from where it formed. Weathering must come first to produce the sediment, followed by transportation to relocate it, deposition to lay it down in layers, and lithification to turn loose sediment into rock. The option that follows this exact progression is the correct one. Choices that place deposition before transport or lithification before deposition, or that start with deposition or transport, don’t reflect the real sequence of forming clastic sedimentary rocks.