Chemistry

Libby Simmons

26 January, 19:53

A geologist is studying an area where stream erosion and deposition are the dominant surface processes. He notices that all of the rock layers in the shallow streambeds have dune features preserved throughout them. Knowing that dunes are formed by the wind in desert settings, what can the geologist conclude about the geologic history of this area? A. The depositional environment has changed from stream-dominated in the past to wind-dominated today. B. Wind must still be the dominant factor shaping the surface today. C. Dunes must also form from streams, at least in this area. D. The depositional environment has changed from wind-dominated in the past to stream-dominated today.