Question

Figure E shows a vertical sequence of sedimentary rocks. From this sequence, which of the following would you infer regarding sea-level change during deposition of these rocks? a. sea level fall (regression) followed by sea level rise (transgression) b. sea level remained low during the entire interval c. these are all shallow water nearshore deposits d. sea level remained high during the entire interval e. these are all offshore deposits

Answer 1

To infer information about sea-level changes from a vertical sequence of sedimentary rocks, we can examine the characteristics of the sedimentary rocks and the fossils they contain.

a. Sea level fall (regression) followed by sea level rise (transgression): This scenario is likely if the sequence of sedimentary rocks shows a change from deeper-water deposits to shallower-water deposits (e.g., from deep marine to nearshore or terrestrial sediments) and is supported by evidence of fossils transitioning from deep-water to shallow-water species.

b. Sea level remained low during the entire interval: This scenario would be suggested if the sedimentary rocks in the sequence predominantly represent terrestrial or shallow-water deposits throughout, and there is no evidence of deep-water fossils.

c. These are all shallow water nearshore deposits: This scenario would be inferred if the sedimentary rocks in the sequence consistently represent nearshore or shallow-water deposits, with no clear evidence of deep-water conditions.

d. Sea level remained high during the entire interval: This scenario would be indicated if the sedimentary rocks in the sequence primarily represent deep-water deposits throughout, with no evidence of shallowing conditions.

e. These are all offshore deposits: This scenario would be suggested if the sedimentary rocks in the sequence consistently represent offshore or deep-water deposits, with no clear evidence of nearshore or shallow-water conditions.

The correct answer would depend on the specific characteristics of the sedimentary rocks in Figure E and any associated fossils. Without more information about the nature of the rocks and the fossils they contain, it's challenging to determine the exact scenario. However, if the sequence shows a transition from deep-water deposits to shallow-water deposits and is associated with a change in the types of fossils present, then option (a) "sea level fall (regression) followed by sea level rise (transgression)" would be a reasonable inference.

Step-by-step explanation: