Exam 10: Deep Time: How Old Is Old

Basaltic clasts within the basal layers of the conglomerate imply which of the following statements? (Choose the most correct answer.)

Relative ages expressed on the geologic time scale primarily resulted from the study of ____________.

Which of the following always varies among multiple isotopes of a single element?

James Hutton,the "father of geology," put forth the principle of ____________.

If horizontal sedimentary strata overlie tilted strata (and no fault is present),the surface between the horizontal and tilted strata must be a(n)____________.

Precisely speaking,a measured radiometric age for a mineral crystal within an igneous rock denotes the amount of time that has passed since the ____________.

Buried erosional surfaces between parallel sedimentary strata are termed ____________.

Radiometric dates applied to sedimentary rocks produce ages that are ____________.

If the relative age of two formations (with respect to one another)is known,then the numerical ages for each formation can be inferred.

Which method of correlation is more reliable for determining age equivalence among bodies of rock that are physically isolated by vast distances?

In an unweathered sample of detrital sedimentary rock,the ratio of an unstable isotope to its stable daughter isotope is 1/15.If no daughters were present at the time the rock cooled below closure temperature,and the half-life of the reaction is 50 million years,how old is the rock?

Two atoms of a single element that differ in number of neutrons are said to represent two distinct ____________ of that element.

In an undisturbed sequence of sedimentary rocks,younger layers overlay older layers,according to the principle of ____________.

The surfaces named contacts #2 and #3 are examples of ____________.

If the numerical ages of two formations are known,then the relative age of each with respect to one another can be inferred.

Which eon of geologic time is represented by rocks containing abundant shelly fossils?

If the lithology and fossil content of two bodies of rock on opposite sides of a canyon are identical,then these remaining outcrops were likely physically connected at one time and formed part of an extensive,sheet-like layer of rock.This idea summarizes the principle of ____________.

The oldest geologic unit in the cross section is the ____________.

The youngest geologic unit visible in the cross section is the ____________.

The correct answer to question 30 illustrates the principle of ____________.