Question

If a relatively young (geologically speaking) stream has a smooth, concave-upward shape, what type of rocks/sediment is it most likely flowing over?

Multiple choice question.
a) Unconsolidated sediment and/or easily eroded rocks
b) Structurally controlled rocks that are resistant to erosion
c) Alternating zones of easily eroded rocks and harder, more resistant rocks

Answer 1

A young stream with a smooth, concave-upward profile typically flows over unconsolidated sediments or easily eroded rocks, allowing for a uniform stream gradient.

Step-by-step explanation:

When examining a young stream with a smooth, concave-upward shape, it is indicative of a stream gradient that decreases evenly from the source to the mouth. As per the characteristics mentioned, the stream most likely flows over: a) Unconsolidated sediment and/or easily eroded rocks. This type of material is less resistant to erosion and allows the stream to maintain a uniform gradient without showing abrupt changes in the profile that would be typical if the stream flowed over variable types of rock with different erosion resistance.