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 starts with breaking down preexisting rock into small pieces (weathering) to create sediment, then moving those pieces away from their source (transportation), followed by settling of the sediments in a basin or environment (deposition), and finally turning the loose sediment into solid rock by compaction and cementation (lithification). This order reflects the physical steps required to form clastic sedimentary rocks: you must first produce the grains, then relocate them, let them accumulate, and only then consolidate them into rock. If deposition occurred before transport, or lithification before deposition, or transport before weathering, the process wouldn’t make physical sense for forming clastic rocks.

The sequence starts with breaking down preexisting rock into small pieces (weathering) to create sediment, then moving those pieces away from their source (transportation), followed by settling of the sediments in a basin or environment (deposition), and finally turning the loose sediment into solid rock by compaction and cementation (lithification). This order reflects the physical steps required to form clastic sedimentary rocks: you must first produce the grains, then relocate them, let them accumulate, and only then consolidate them into rock. If deposition occurred before transport, or lithification before deposition, or transport before weathering, the process wouldn’t make physical sense for forming clastic rocks.