Geologic Time

Question 1

Visualize 5 horizontal sedimentary strata exposed in a cliff or canyon wall identified by consecutive numbers, 1 being the lowest bed and 5 being the highest. Which of the following statements concerning the strata are true?

Answer 1

Beds 1 and 3 are older than bed 4.

Question 2

_____ is an erosional contact between tilted, older strata below and horizontal, younger strata above.

Answer 2

An angular unconformity

Question 3

Which of the following refers to the investigative process by which geologist identify and match sedimentary strata and other rocks of the same ages in different areas?

Answer 3

Correlation

Question 4

The ____ is the idea or concept that’s ancient life forms succeeded each other in a definite, evolutionary patter and that the contained assemblage of
Fossils can determine geologic ages of strata.

Answer 4

Principle of faunal succession

Question 5

The ratio of parent to daughter isotopes in a radioactive decay process is .4. How many half lives have elapsed since the material was 100% parent atoms?

Answer 5

Between 1 and 2

Question 6

What is meant by “zoic”?

Answer 6

Life; living things

Question 7

The period of “ancient life” is the _____ era.

Answer 7

Paleozoic

Question 8

About 88% of geologic time is represented by the time span called the _____.

Answer 8

Precambrian

Question 9

What is the age of earth most accepted by

Scientists today?

Answer 9

4.5 billion years

Question 10

Which of the following denotes the divisions of the geologic time scale in correct order of decreasing lengths of time beginning with the longest time interval and ending with the shortest?

Answer 10

Eon, era, period, epoch

Question 11

Pebbles of granite in sandstone and conglomerate resting on the granite suggest that the granite intruded the sedimentary beds.

Answer 11

False

Question 12

A disconformity is an erosional unconformity with parallel beds or strata above and below.

Answer 12

True

Question 13

Rapid burial and possession of hard parts are necessary conditions for the preservation of plant or anima remains as fossils.

Answer 13

True

Question 14

Phanerozoic, marine, sedimentary strata of the same age on different continents can usually be correlated by the fossil assemblages.

Answer 14

True

Question 15

An unconformity is a buried_______.

Answer 15

Surface of erosion separating younger strata above from older strata below.