a rock's age compared to the ages of other rocks
Paleontologist
Intrusion
layers of sediment compressed into rock
the preserved remains or traces of living things
scientist who studies fossils to learn about organisms that lived long ago
When large numbers of fossils are found in a layer of sedimentary rock, a mass _______________ has occured.
Extinction
Absolute age
the almost exact number of years since a rock formed
when magma forces itself into existing rock and hardens
Superposition
Sedimentary rock
the law that states the oldest layers are at the bottom in sedimentary rock
Extrusion
Fossil
Relative age
a layer formed when lava comes to the surface and hardens
