Exercise 9.2. Final Questions

a.   The top surface of the granite at the base of Cores 1 to 3 is a nonconformity because clastic sediments are deposited on top of an igneous rock.

i.   What is the age of the time-stratigraphic unit on top of the granite?

ii.   Where was the deepest part of the depositional or sedimentary basin during this time? ­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­How do you know?

­­­­­­­­­­­­­­­­­­­­­­­iii.   What happened to water depth between this time-stratigraphic unit and the one above it (that is, the first two units above the nonconformity)? How can you tell?

iv.   In which direction did the shoreline move between the first two units above the nonconformity? (Left or right?)

b.   What major change in sedimentary rock type occurred between the second-oldest and third-oldest rock units?   What does this say about any change in climate at this location?

c.  Where was the shoreline during the Mesozoic? (Is it represented in a particular core, to the right, to the left, etc.) Explain your reasoning.

d.  Where was the shoreline during the most recent time unit? (Is it represented in a particular core, to the right, to the left, etc.) Explain your reasoning.