Final answer:
Graded beds in a rock outcrop suggest a sedimentary sequence was deposited rapidly, often due to turbidity currents underwater.
Step-by-step explanation:
When graded beds are observed in a rock outcrop, this tells geologists that a sedimentary sequence was deposited rapidly. Graded bedding is characterized by a range of grain sizes within a single layer, with coarser particles at the bottom and finer particles towards the top. This is typically the result of turbidity currents, which are underwater sediment slides or flows that occur on continental slopes. The sediment revealed by these currents is known as a turbidite. The size gradation happens because as the energy of the current wanes, it no longer has the strength to transport the larger particles, so they are deposited first, followed by progressively smaller particles.