What does the principle of original horizontality state about sediment deposition?

What does the principle of original horizontality state about sediment deposition?

• A. Sediments are deposited in flat layers
• B. Sediments are deposited in vertical layers
• C. Basins are always flooded
• D. No statement about deposition

Answer: (A)

Sediments settle from a transporting medium (water or air) under gravity, so they accumulate as nearly horizontal beds that lie flat with the surface. As particles drop out of suspension, each layer forms parallel to the surface because there’s no strong force to push them into vertical stacking. Over time, countless thin, flat layers build up, producing horizontal strata. If rocks later get tilted or folded, we can still infer that the original deposition was flat and horizontal. This is why the statement about flat, horizontal deposition is the best description.

Sediments settle from a transporting medium (water or air) under gravity, so they accumulate as nearly horizontal beds that lie flat with the surface. As particles drop out of suspension, each layer forms parallel to the surface because there’s no strong force to push them into vertical stacking. Over time, countless thin, flat layers build up, producing horizontal strata. If rocks later get tilted or folded, we can still infer that the original deposition was flat and horizontal. This is why the statement about flat, horizontal deposition is the best description.