During what geological period was the sandstone deposited? ...

[mmm]

During what geological period was the sandstone deposited?
 
  What will be an ideal response?

Question 2

Which principle(s) would you use to determine the relative ages of an intrusive igneous rock, such as a dike, and the rock adjacent to the dike? Why?
 
  What will be an ideal response?

[jaymee143]

Answer to Question 1

Jurassic, because the sandstone contains a Jurassic fossil.

Answer to Question 2

Principle of cross-cutting relationships and possibly the principle of inclusions

[mmm]

Excellent

[smrtceo]

Thanks for the timely response, appreciate it