After a rock layer is eroded, which additional event must occur to create an unconformity, or a gap, in the geological record?
a. an earthquake or motion along a fault
b. new sediment deposits build up on the eroded area
c. radioactive decay along a fault
d. a volcanic eruption near the eroded area
I think that it is either B or D.
I find it funny that connexus found people cheating and changed the answers
Nope.
Then it must be C?
B is correct.
To determine the correct answer, let's analyze the given options:
a. an earthquake or motion along a fault: This option involves the movement of rock layers and can cause folding, faulting, or displacement. However, it does not necessarily create a gap or unconformity in the geological record.
b. new sediment deposits build up on the eroded area: This option suggests that new layers of sediment are deposited over the eroded area. As a result, there can be a time gap in the geological record, indicating an unconformity. This is a possible correct answer.
c. radioactive decay along a fault: Radioactive decay is a natural process occurring within rocks and minerals that involves the emission of radiation. While radioactive decay can affect the ages of rock layers, it does not directly create an unconformity or gap in the geological record.
d. a volcanic eruption near the eroded area: Volcanic eruptions can deposit layers of ash and lava flows, which become part of the geological record. However, a volcanic eruption near an eroded area does not necessarily create an unconformity or gap in the geological record.
Based on the explanations above, the correct answer is b. new sediment deposits build up on the eroded area. When new sediment deposits accumulate and cover the eroded area, a gap or unconformity in the geological record is created.