Four rock outcrops, labeled 1, 2, 3, and 4, found within the same plateau, are represented below. Index
fossils found in some of the rock layers are shown. The rock layers have not been overturned.
Which rock layer is the youngest?
(1) sandstone in outcrop 1
(2) breccia in outcrop 2
(3) conglomerate in outcrop 3
(4) sandstone in outcrop 4
