A) 1 B) 2 C) 3 D) 4

1. The geologic time line below represents the three most recent geologic eras. The numbers representevents in Earth's history.

Which number best represents when humans are inferred to have first appeared on Earth?

A) absolute dating techniquesB) fossil evidenceC) climatic changesD) seismic data

2. The division of Earth's geologic history into units oftime called eons, eras, periods, and epochs is based on

A) Archean ® Mesozoic ® Cenozoic ® Paleozoic® Proterozoic

B) Archean ® Proterozoic ® Paleozoic ® Mesozoic ® Cenozoic

C) Cenozoic ® Mesozoic ® Paleozoic ® Proterozoic ® Archean

D) Cenozoic ® Paleozoic ® Archean ® Mesozoic® Proterozoic

3. Which sequence shows the correct order of Earth’sgeologic time intervals from oldest to youngest?

A) appearance of the earliest grassesB) appearance of the earliest birdsC) the Grenville OrogenyD) the intrusion of the Palisades Sill

4. Which event occurred earliest in geologic history?

A) Neogene B) CretaceousC) Triassic D) Cambrian

5. Trilobite fossils were recently discovered inHimalayan Mountain bedrock. During which geologicperiod could these organisms have lived?

A) 4.6 × 106 years B) 4.6 × 107 yearsC) 4.6 × 108 years D) 4.6 × 109 years

6. What is the estimated age of Earth?

A) 66 million years agoB) 144 million years agoC) 163 million years agoD) 190 million years ago

7. When did the Jurassic Period end?

A) 37% B) 50% C) 67% D) 87%

8. Approximately what percent of geologic time sincethe estimated origin of the Earth is represented by thePrecambrian Era?

A) 10.0 m B) 2.5 mC) 3.8 m D) 4.5 m

9. Students plan to construct a geologic time line of theEarth's history from its origin to the present time.They will use a scale of 1 meter equals 1 billionyears. What should be the total length of the students'time line?

A) 50 grams B) 100 gramsC) 200 grams D) 400 grams

10. How much of an 800-gram sample of potassium-40will remain after 3.9 × 109 years of radioactivedecay?

A) 5,700 years B) 17,100 yearsC) 22,800 years D) 28,500 years

11. How old is a fossil that has radioactively decayedthrough 4 half-lives of carbon-14?

A) amount of the substanceB) composition of the substanceC) pressure acting on the substanceD) temperature of the substance

12. The half-life of a radioactive substance is mainlycontrolled by the

A) A B) B C) C D) D

13. The graph below shows the relationship betweenmass and time for four radioactive elements duringradioactive decay.

Which line best represents the decay curve forpotassium-40?

A) 1/8 as long B) 1/64 as longC) 8 times longer D) the same

14. Base your answer on the diagram below whichrepresents a cube of radioactive material (figure A)cut into eight identical cubes (figure B).

Compared to the half-life of the material in figure A,the half-life of the material in each small cube infigure B is

A) eurypterids B) graptolitesC) birds D) placoderm fish

15. Which group of organisms has the shortest record oflife on Earth?

A) under a shallow sea containing tropicalwaters

B) higher in elevation and eroded extensively byglaciers

C) covered by extensive lava f1owsD) impacted by comets and asteroids

16. Devonian-age fossils found in New York Statebedrock, such as Manticoceras and Mucrospirifer, provide evidence that parts of New York State wereonce

A) end of the last ice ageB) breaking up of the supercontinent PangeaC) evolution of the first birdsD) extinction of the dinosaurs

17. Scientists believe that a large asteroid struck Earthapproximately 65 million years ago. It is oftentheorized that this event contributed to the

A) Pleistocene EpochB) Pennsylvanian EpochC) Precambrian EraD) Paleozoic Era

18. The cartoon below illustrates possible interactionbetween humans and mammoths.

During which geologic timespan could this "game"have ocurred?

A) conglomerate containing the tusk of amastodont

B) shale containing trilobite fossilsC) sandstone containing fossils of flowering plantsD) siltstone containing dinosaur footprints

19. Which rock is most likely the oldest?

A) Pliocene B) MioceneC) Oligocene D) Eocene

20. A skull was discovered that has humancharacteristics and is about 2.8 million years old.Based on this information, during which epochcould early humans have existed?

A) the extinction of many kinds of marineanimals

B) the extinction of many kinds of land animalsC) the development of primitive aquatic plantsD) the development of birds and mammals

21. Which event occurred at the time of the AlleghenianOrogeny?

A) the extinction of the armored fishesB) the extinction of the mastodontC) the appearance of the reptileD) the appearance of the dinosaur

22. Which event occurred at the start of the MesozoicEra?

A) meteor showersB) melting of glacial iceC) volcanic eruptionsD) evaporation of seawater

23. The gases in Earth's early atmosphere are inferred tohave come primarily from

A) fish amphibians mammals soft-bodied organisms

B) fish soft-bodied organisms mammals amphibians

C) soft-bodied organisms amphibians fish mammals

D) soft-bodied organisms fish amphibians mammals

24. According to the fossil record, which sequencecorrectly represents the evolution of life on Earth?

A) addition of free oxygen to Earth’satmosphere

B) formation of clastic sedimentary rocksC) movement of tectonic platesD) filling of the oceans by precipitation

25. Which event in Earth’s history was dependent on thedevelopment of a certain type of life-form?

A) brachiopods B) eurypteridsC) graptolites D) trilobites

26. Which group of organisms, some of which werepreserved as fossils in early Paleozoic rocks, are stillin existence today?

A) trilobite B) humanC) coelophysis D) stromatolite

27. Which life-form appeared first?

A) wide geographic area and existed for a longgeologic time

B) wide geographic area and existed for a shortgeologic time

C) limited geographic area and existed for a longgeologic time

D) limited geographic area and existed for a shortgeologic time

28. Organisms that later became good index fossils livedover a

A) A B) B C) C D) D

29. The three cross sections of sedimentary bedrockshown below represent widely separated surfaceexposures of layers that contain fossils. Letters A, B,C, and D represent four different marine fossilsfound in these rock layers.

Which letter best represents an index fossil?

A) Gayle shaleB) Freeport sandstoneC) Erie coal, but before formation of Freeport

sandstoneD) Dunbar limestone, but before formation of Erie

coal

30. The diagram below represents a geologic crosssection of a portion of Earth's crust.

Folding and erosion occurred after the formation ofthe

31. Base your answer to the following question on thegeologic cross section below of the Grand Canyon.The numbers 1 through 10 represent Paleozoicsedimentary rock layers.

A) a gap in the geologic time recordB) an intrusion of igneous rockC) an abundance of fossilsD) a region of metamorphic rock

The unconformity between the Paleozoicsedimentary rocks and the Precambrian sedimentaryrocks represents

A) Cambrian and OrdovicianB) Silurian and DevonianC) Pennsylvanian and MississippianD) Triassic and Jurassic

32. During which two geologic time periods did most ofthe surface bedrock of the Taconic Mountains form?

A) the opening of the Atlantic OceanB) the uplift of the Appalachian MountainsC) the formation of the Catskill DeltaD) the intrusion of the Palisades Sill

33. Which geologic event occurred in New York State atapproximately the same time that eurypterids werebecoming extinct?

A) A B) B C) C D) D

34. The cross section below shows four rock units, A, B,C, and D.

Which rock unit is youngest in age?

A) D C B A FB) A B C D FC) F D C B AD) F A B C D

35. The cross section below shows rock layers A, B, C,D, and fault F. The rock layers have not beenoverturned.

Which sequence places the rock layers and fault inorder from oldest to youngest?

36. Base your answer to the following question on the block diagram below, which shows a portion ofEath's crust. Letters A, B, C, and D indicate sedimentary layers.

A) formation of layer AB) formation of layer DC) tilting of all four sedimentary rock layersD) erosion of the igneous rock exposed at the surface

Which event occurred most recently?

A) The fault is younger than all the layers itcuts across.

B) The fault is older than all the layers it cutsacross.

C) The fault is the same age as the top layer it cutsacross.

D) The fault is the same age as the bottom layer itcuts across.

37. What is the relative age of a fault that cuts acrossmany rock layers?

A) deposition of sediments for rock layer AB) formation of the faultC) intrusion of the igneous material ED) cementation of sediments for rock layer D

38. The geologic cross section below shows sedimentaryrock layers A, B, C, and D, which have not beenoverturned. E is an igneous intrusion. Line XY represents a fault.

Which geologic event occurred most recently?

A) The sandstone is younger than the basalt.B) The shale is younger than the basalt.C) The limestone is younger than the shale.D) The limestone is younger than the basalt.

39. Which statement correctly describes an agerelationship in the geologic cross section below?

A) decrease, onlyB) increase, onlyC) decrease, then increaseD) increase, then decrease

40. The diagram below shows a geologic cross sectionof a portion of the Earth's crust that has not beenoverturned.

An observer travels across the surface from point A to point B, measuring the age of the surfacebedrock. The observer finds the age of the surfacebedrock to

Answer KeyEarth's History 2012

1. D2. B3. B4. C5. D6. D7. B8. D9. D10. B11. C12. B13. D14. D15. D16. A17. D18. A19. B20. A21. A22. D23. C24. D25. A26. A27. D28. B29. C30. C31. A32. A33. C34. A35. A

36. D37. A38. C39. B40. D