Fossils Are Common in __

Q16: Isotopic dates from volcanic ash or lava

Q17: Uniformitarianism reflects the belief among geologists that

Q18: Isotopic dating has shown that the Precambrian

Q19: A(n) _ is a contact in which

Q20: A(n) _ is an erosional surface that

Q22: The half-life of the carbon 14 isotope

Q23: Under some circumstances, correlation between two regions

Q24: In an unconformity the contact represents a

Q25: The _ Era began with the appearance

Q26: The principle of crosscutting relationships states that