EARTH SCIENCE Assignment # _____

Name:_____________________________________________Date:__________________Period:_____

Regents Questions Geologic Time, Fossils, Radioactive Dating

August 2014

16 Rifting of tectonic plates in eastern North America during the Jurassic Period was responsible for the

(1) formation of the Catskill delta (3) Alleghenian orogeny

(2) first uplift of the Adirondack Mountains (4) opening of the Atlantic Ocean

18 Much of the evidence for the evolution of lifeforms on Earth has been obtained by

(1) studying the life spans of present-day animals (3) correlating widespread igneous ash deposits

(2) radioactive dating of metamorphic rock (4) examining fossils preserved in the rock Record

19 The table below shows the radioactive decay of carbon-14. Part of the table has been left blank.

After 22,800 years, approximately what percentage of the original carbon-14 remains?

(1) 15%

(2) 12.5%

(3) 6.25%

(4) 3.125%

Base your answers to questions 36 and 37 on the data table below and on your knowledge of Earth science.

The data table shows information on six major mass extinction events that occurred many million years ago

(mya) in Earth’s history.

36 More than half of brachiopod species became extinct at the end of the

(1) Devonian Period (2) Silurian Period (3) Ordovician Period (4) Cambrian Period

37 Which event is generally accepted as the cause of the mass extinction that occurred 65.5 million years ago?

(1) volcanic eruption (2) continental collision (3) asteroid impact (4) sea-level change

Base your answers to questions 44 through 47 on the geologic cross section below and on your knowledge of

Earth science. The cross section represents rock and sediment layers, labeled A through F. Each layer contains

fossil remains, which formed in different depositional environments. Some layers contain index fossils. The

layers have not been overturned.

44 Which pair of organisms existed when the unconsolidated sediment in layer A was deposited?

(1) birds and trilobites (3) ammonoids and grasses

(2) dinosaurs and mastodonts (4) humans and vascular plants

45 Which rock layer formed mainly from the compaction of plant remains?

(1) E (2) B (3) C (4) F

46 During which geologic epoch was layer F deposited?

(1) Late Devonian (2) Middle Devonian (3) Early Devonian (4) Late Silurian

47 The depositional environment during the time these layers and fossils were deposited

(1) was consistently marine (3) changed from marine to terrestrial (land) (2) was consistently terrestrial (land) (4) changed from terrestrial (land) to marine

Base your answers to questions 51 through 54 on the cross section of part of Earth’s crust in your answer

booklet and on your knowledge of Earth science. On the cross section, some rock units are labeled with letters A

through I. The rock units have not been overturned. Line XY represents a fault. Line UV represents an

unconformity.

51 On the cross section below, draw two arrows, one on each side of line XY, to show the

direction of relative movement that has occurred along the fault. [1]

52 Write the letter of the oldest rock unit in the cross section. [1]

53 Identify the contact metamorphic rock that formed between rock units B and C. [1]

54 The table below shows the ages of the igneous rock units, determined by radioactive dating.

How many million years ago did rock unit I most likely form? [1]

June 2014

7 Fossils of which type of animal would most likely be found in the surface bedrock of the Catskills?

(1) reptiles (2) brachiopods (3) mammals (4) birds

8 Which geologic event occurred in New York State at approximately the same time as the extinction

of dinosaurs and ammonoids?

(1) formation of the Queenston Delta

(2) deposition of the sands and clays underlying Long Island

(3) initial opening of the Atlantic Ocean

(4) advance and retreat of the last continental ice sheet

9 The impacts of large asteroids on Earth are inferred to be associated with

(1) free oxygen entering Earth’s atmosphere (3) the creation of subduction zones

(2) seafloor spreading (4) global climatic changes

10 Volcanic ash deposits found in the geologic record are most useful in correlating the age of

rock layers if the volcanic ash was distributed over a

(1) large area during a short period of time (3) small area during a short period of time

(2) large area during a long period of time (4) small area during a long period of time

11 A fossil formed 11,400 years ago. Which percentage of the original amount of carbon-14

remains in the fossil?

(1) 100% (2) 50% (3) 25% (4) 12.5%

31 The cross section below represents four different rock units. The symbol for contact metamorphism has been

omitted from the cross section.

The sequence below represents the relative ages of the rock units from oldest to youngest.

limestone → granite → shale → sandstone

Which cross section below represents where the symbol for contact metamorphism would be located, based on

the relative age sequence?

Base your answers to questions 49 on the photograph and cross section below and on your

knowledge of Earth science. The sequence of rock types found in the walls of the Grand Canyon are shown.

The names of rock formations are shown and the upper and lower boundaries of each formation are indicated by

dashed lines. The rock layers have not been overturned.

49 The sequence of rock layers in the cross section provides evidence that the Muave formation is

(1) younger than the Temple Butte, but older than the Bright Angel

(2) younger than both the Temple Butte and the Bright Angel

(3) older than the Temple Butte, but younger than the Bright Angel

(4) older than both the Temple Butte and the Bright Angel

Base your answers to questions 72 through 74 on the passage and diagram below and on your knowledge of

Earth science. The diagram represents some of the Burgess shale community of organisms that existed

together during part of the Cambrian Period. Thirteen different types of organisms are numbered in the diagram.

Burgess Shale Fossils

The Burgess shale fossil discovery revealed unique Cambrian life-forms, most of

which were not present in the previously known fossil record. Normally, soft body parts

of dead organisms are destroyed by scavengers and bacteria on the ocean floor.

However, in the deep-water depositional environment of the Burgess shale, oxygen was

lacking and organisms were buried rapidly, preserving the unique community seen in

the diagram. The soft-bodied organisms had previously been unknown. The Burgess

shale fossils were originally found in a layer of bedrock in southwestern Canada.

72 During which epoch of the Cambrian Period were the Burgess shale organisms and sediments deposited? [1]

73 Explain why so many soft body parts of organisms were preserved in the Burgess shale. [1]

74 Identify the number of one organism in the diagram that is most likely a trilobite. [1]

January 2014

13 The major source of oxygen in Earth's Early Proterozoic atmosphere is inferred to have been produced by

(1) oceanic cyanobacteria (3) radioactive decay in Earth's inner core

(2) outgassing from volcanic eruptions (4) evaporation of ocean water

14 Earth has sedimentary bedrock of marine origin that is four billion years old. Which inference can be made from

this information?

(1) Earth had oceans four billion years ago.

(2) Sedimentary rocks formed from magma when Earth cooled four billion years ago.

(3) Most sedimentary rocks are at least four billion years old.

(4) Life existed on Earth four billion years ago.

15 Valcouroceras is a New York State index fossil. Which mountain-building event occurred in New York State

during the time when Valcouroceras was living in oceans covering parts of New York State?

(1) Alleghenian orogeny (2) Acadian orogeny (3) Taconian orogeny (4) Grenville orogeny

16 The diagram below represents some fauna (animals) found fossilized in Canada's Burgess shale.

39 The diagram below represents three bedrock outcrops. The layers have not been overturned. Letters A through E identify different rock layers. Fossils found in the rock layers are 'shown.

Which fossil could be classified as an index fossil?

Base your answers to questions 54 and 55 on the data table and information below and on your knowledge of Earth science. The data table shows the radioactive decay of carbon-14 and the age of fossil remains, in years (y).

Part of the table has been left blank.

During which geologic epoch did these

animals live?

(1) Middle Cambrian

(2) Early Pennsylvanian

(3) Late Triassic

(4) Paleocene

54 Identify the decay product when carbon-14 undergoes radioactive disintegration, [l]

55 The carbon-14 in the fossil remains of a mastodont has undergone five half-lives of radioactive decay. Calculate the age of these fossil remains, [l]

Base your answers to questions 56 through 60 on the geologic cross section of Earth s crust below and on your knowledge of Earth science. Letters A through F identify rock units. Letter X identifies a fault. Wavy line YZ represents an

unconformity. The locations of contact metamorphism and the map symbols for sedimentary rock layers B and E have

been omitted.

56 On the cross section above, draw two arrows, one on each side of fault X, to show the relative direction of movement

of the rock units that occurred during faulting, [l]

57 Layer B is composed of clay-sized particles and layer E is composed of halite crystals. On the cross section

above, fill in layer B and layer E on both sides of the fault with the correct sedimentary rock map symbols, [l]

58 On the cross section above, draw the contact metamorphism symbol to indicate all locations where contact

metamorphism has occurred, [l]

59 Indicate the relative ages of geologic features B, E, F, and X, by listing the letters from oldest to most recent, [l]

60 Identify tivo processes that produced the unconformity, [l]

August 2013

2 Which event occurred approximately 4.6 billion years ago?

(1) evolution of the earliest fish (3) formation of the oldest known Earth rocks

(2) evolution of stromatolites (4) formation of Earth and our solar system

32 Which pie graph best shows the relative length of time of the major intervals of Earth’s geologic history?

Base your answers to questions 44 through 47 on the cross section below and on your knowledge of Earth

science. The cross section represents rock units that have not been overturned. Lines CC’ and GG’ represent

unconformities. The geologic ages of some of the lettered rock units are shown below the cross section.

46 The diagrams below represent three index fossils found in one of the rock units.

These fossils are most likely found in

(1) rock unit I (2) rock unit J (3) rock unit K (4) rock unit M

44 Which rock unit was formed most recently?

(1) A (2) F (3) L (4) M

45 Why is there no contact metamorphism

indicated between rock unit L and rock unit F?

(1) Conglomerate does not metamorphose.

(2) The intrusion was not hot enough to

metamorphose rock unit F.

(3) The contact metamorphism within rock unit F

eroded away.

(4) Rock unit F was deposited after the intrusion

of rock unit L.

47 Which inference about rock units D, E, and H can best be supported by evidence in the cross section?

(1) They contain mostly sand-sized sediment.

(2) They contain both land and marine fossils.

(3) They were altered by contact metamorphism.

(4) They were deposited as horizontal layers and were later tilted.

Base your answers to questions 55 through 58 on the cross sections below and on your knowledge of Earth

science. The cross sections represent three bedrock outcrops, 1, 2, and 3, found several kilometers apart.

The geologic time period when each sedimentary rock layer formed is shown. The symbols:

represent fossils of different types of organisms present in the rock layers.

55 Draw the fossil symbol that represents the best index fossil. Describe one piece of evidence shown in the

outcrops that indicates that this fossil has characteristics of a good index fossil. [1]

56 Write the outcrop number of the cross section that could be found in New York State. Describe the

evidence that supports your answer. [1]

57 Explain why the geologic age of these rock layers could not be accurately dated using carbon-14. [1]

58 Explain why the index fossil Coelophysis is not preserved in any of the rock outcrops. [1]

June 2013

14 What percentage of Earth’s history represents human existence?

(1) less than 1.0% (2) 1.8% (3) 23.5% (4) more than 98.6%

15 During which period in geologic history did the uplifting of the Adirondack Mountains begin?

(1) Quaternary (2) Cretaceous (3) Triassic (4) Cambrian

17 The cross sections below represent three widely separated bedrock outcrops labeled A, B, and C.

Letters W, X, Y, and Z represent fossils found in the rock layers.

18 Which scientific principle states that younger rock layers are generally deposited on top of older rock layers?

(1) superposition (2) evolution (3) original horizontality (4) inclusion

Base your answers to questions 48 through 50 on the geologic cross section and photograph below and on

your knowledge of Earth science. The cross section represents the Palisades sill in southern New York State and

the surrounding bedrock. Potassium-40 analysis determined the sill to be approximately 200,000,000 years old.

The photograph shows a mastodont tooth found in glacial sediments nearby. Carbon-14 analysis determined this

tooth to be approximately 11,400 years old.

48 Which metamorphic rock was most likely produced in the contact zone between the Palisades sill and the

sedimentary rock?

(1) schist (2) slate (3) gneiss (4) quartzite

49 Potassium-40 is useful for radioactive dating of the Palisades sill because the half-life of potassium-40

(1) decreased as the amounts of 40

Ar and 40

Ca in the sill increased

(2) remained constant during the radioactive decay process

(3) increased as pressure from the overlying sedimentary rock increased

(4) was shortened by the high temperature of the magma that formed the sill

Which fossil could best be used

as an index fossil?

(1) W

(2) X

(3) Y

(4) Z

50 The mastodont tooth and the entire Palisades sill represented above are similar in that both

(1) can be found in deposits left by the last continental ice sheet in New York State

(2) are fossils of animals that once lived in New York State

(3) can be used as time markers to date nearby geologic events

(4) are Mesozoic in age

Base your answers to questions 60 and 61 on the partial geologic map below and on your

knowledge of Earth science. The map shows the geographical distribution of most of the Devonian-age

surface bedrock in New York State.

60 On the map, place an X at a location where the gastropod fossil Platyceras might be found in the surface

bedrock. [1]

61 State the name of the New York State landscape region that includes most of the Devonian-age surface

bedrock shown on the map. [1]