Correct Response: C. Graded bedding in sedimentary rock strata is the change in sediment grain size from the base of the bed to the top. Normal graded bedding is the most common and shows coarser grain size at the bottom with increasingly finer sediments toward the top of the bed. This kind of bedding is often associated with sedimentary rocks that formed in marginal marine environments, such as coastal deltas and turbidity flows. Desert depositional environments (A) such as a dune and high-energy beach deposits (B) are more likely to exhibit cross-bedding with little change in grain size. Alluvial fan sediments (D) are typically deposited rapidly during flash floods and as a consequence are usually composed of heterogeneous sediments that have poorly defined bedding or no bedding at all.
