6th Ch 10 L2 Relative Age Dating

According to the principle of superposition, which statement is true about the sediment layers shown here?

• Layer 2 is young relative to layer 3
• Layer 3 is young relative to layers 1, 2, and 4
• Layer 4 is old relative to layers 1 and 2
• Layer 2 is old relative to layers 3 and 4

After a river erodes a valley through several layers of rock, the layers will be the same on each side of the valley, according to which principle?

• superposition
• original horizontality
• lateral continuity
• cross-cutting relationships

Which statement about relative ages is true?

• Segments of included rock are older than the surrounding rock in which they are included
• Lower layers of rock are younger compared to upper layers
• Layers of rocks are all younger than a fault line that cuts through them
• A magma dike is older than all of the rocks into which it has intruded

When sedimentary rock is deposited on top of igneous or metamorphic rock, scientists call this __________.

• disconformity
• angular unconformity
• nonconformity
• normal unconformity

Which is not a property of the organisms that have become useful index fossils?

• The organisms existed for a relatively short period of time
• The organisms existed over a large area
• The organisms were abundant when they existed
• The organisms still exist today