If the same index fossils are found in two separate rock layers, the two rock layers most
a. reveal a disconformity. b.reveal a nonconformity. c.were formed at the same time. d.were formed at different times.

Which set of characteristics best describes sedimentary rock? a) largest type of rock, made of organic matter, hardest type of rock b) often contains layers, forms near sources of water, contains fossils c) least abundant type of rock, made of other rocks, made mostly of minerals d) most abundant type in earth's crust, made of magma/lava, contains no fossils