The Cretaceous Is A(n)

Q7: The process of matching up rock layers

Q8: The first 87% of geologic time is

Q9: A(n) _ is any indication of prehistoric

Q10: A dike that intrudes a bed of

Q11: If a rock sample contains uranium and

Q13: Breaks, or gaps, in the rock record

Q14: Which of the following radionuclides is used

Q15: Geologic evidence places Earth's age at _

Q16: Which of the following radionuclides has the

Q17: Petrified wood is a common type of