Geology 1100 Homework 6

How has Earth's crust changed since it first formed? Choose one: A. The crust is much more silicic than the initial crust. B. There has been no change in Earth's crust. C. The crust is much more mafic than the initial crust.

A. The crust is much more silicic than the initial crust.

In 1815, William Smith correlated strata from many locations and plotted the information on paper to show the spatial distribution of rock units on the Earth's surface. This document was the first modern Choose one: A. geologic map. B. geologic time scale. C. stratigraphic column. D. geologic column.

A. geologic map.

The Paleozoic Era ended with a mass extinction event that was likely caused by Choose one: A. intense volcanic activity. B. the formation of Pangaea. C. the formation of high-latitude ice sheets. D. the evolution of land plants.

A. intense volcanic activity

An unconformity develops when Choose one: A. new strata are deposited atop eroded strata. B. old strata erode beneath new strata. C. new strata are deposited atop old strata without missing time. D. new strata mix with old strata.

A. new strata are deposited atop eroded strata

Identify the time interval when vascular plants shared the land with spiders, scorpions, insects, and crustaceans, while jawed fish cruised the oceans and the first amphibians left water to visit land. Choose one: A. middle Proterozoic B. middle Paleozoic C. early Cenozoic D. late Mesozoic

B. middle Paleozoic

A radioactive isotope of the element potassium decays to produce argon. If the ratio of argon to potassium in a mineral is found to be 7:1, how many half-lives have occurred since the mineral cooled below its closure temperature? Choose one: A. 8 half-lives B. 1 half-life C. 7 half-lives D. 3 half-lives

D. 3 half-lives

The principle of lateral continuity says that Choose one: A. the feature doing the cutting is younger than the feature it cuts. B. in a sequence of sedimentary beds, the oldest is on the bottom. C. sedimentary layers began as continuous expanses of sediment. D. rock containing inclusions is younger than the inclusions.

C. sedimentary layers began as continuous expanses of sediment

Which of the following is a method used to determine numerical age? Choose one: A. correlating strata B. cross-cutting relations C. fossil correlation D. counting tree rings

D. counting tree rings

How many half-lives have passed if a rock contains 25% parent isotopes and 75% daughter isotopes?

2

In which time period did the first feathered birds appear? Choose one: A. Jurassic B. Paleozoic C. Pleistocene D. Cambrian

A. Jurassic

How did the Cambrian explosion of life change the nature of the living world? Choose one or more: A.Numerous filter feeders and deposit feeders and large, mobile predators complicated the world food web. B.It created greenhouse conditions and eventually led to widespread epicontinental seas. C.Many defensive structures and behaviors were favored in natural selection due to the proliferation of carnivores. D.Reef-forming organisms had yet to evolve.

A. Numerous filter feeders and deposit feeders and large, mobile predators complicated the world food web. C. Many defensive structures and behaviors were favored in natural selection due to the proliferation of carnivores

In this illustration, which is a correct interpretation of relative ages? Choose one: A. The granite pluton is older than the fault, which is older than the dike. B. All of the possible answers are correct. C. The granite pluton is older than the folded layers. D. The fault is older than the folded layers, which are younger than the granite.

A. The granite pluton is older than the fault, which is older than the dike

Which of the following is the MOST PRECISE estimate of when the folding occurred? Choose one: A. before the granite pluton intruded, and after intrusion of the sill B. before the fault formed and after layer 5 was deposited C. before erosion of the land surface D. before the basalt dike intruded and after layer 6 was deposited

A. before the granite pluton intruded, and after intrusion of the sill

Geologists believe that the impact of a 13-km-wide meteorite 65 million years ago Choose one: A. generated a hot-air blast and blaze that caused worldwide forest fires. B. ejected molten debris into the atmosphere that produced acid rain. C. generated 20-km-high tsunamis D. ejected chemicals into the atmosphere that caused thousands of years of winter-like night conditions that halted photosynthesis.

A. generated a hot-air blast and blaze that caused worldwide forest fires.

Which of the following statements is true? Choose one: A. The Mesozoic is known as the Age of Mammals. B. Fossils of modern humans (Homo sapiens) date back about 200,000 years. C. The human genus, Homo, first appeared more than 7 million years ago. D. Hominins first appeared in the late Mesozoic.

B. Fossils of modern humans (homo spiens) date back about 200,000 years

Which of the illustration represents a disconformity? Choose one: A. Illustration A B. Illustration B C. Illustration C

B. Illustration B

Theoretically, "snowball Earth" conditions of the late Proterozoic Eon would have persisted forever were it not for greenhouse warming caused by Choose one: A. oxygen. B. carbon dioxide. C. carbon monoxide. D. ammonia.

B. carbon dioxide

The Hadean Eon ; Choose one: A. is the span of time between the formation of the Earth and the age of the oldest known rocks. B. is a span of time that equates to the late heavy bombardment. C. is the span of time before the formation of the Earth. D. is a span of time during which the Earth's surface was entirely molten.

A. is the span of time between the formation of the Earth and the age of the oldest known rocks

Geologists base their estimate that the Earth is 4.56 billion years old on Choose one: A. isotopic dating of meteorites thought to be from primitive solids of the early Solar System. B. the rate of cooling of the Earth since it formed. C. cross-cutting relationships. D. radiometric age dates on rocks from Wyoming.

A. isotopic dating of meteorites thought to be from primitive solids of the early Solar System

What conclusion can you make from the following diagram? Choose one: A. If the half-life of the parent material is 4,000 years, 3 on the horizontal axis of the graph represents 12,000 years. B. Equal amounts of parent and daughter material are present after the passage of two half-lives. C. All of the possible answers are correct. D. If 2 g of parent material is present after three half-lives, 6 g of daughter material will also be present.

A. If the half-life of the parent material is 4,000 years, 3 on the horizontal axis of the graph represents 12,000 years

Which of the following is most useful for justifying your age assessment? Choose one: A. principle of superposition B. principle of cross-cutting relations C. principle of baked contacts D. principle of original horizontality

A. principle of superposition

A stratigraphic formation is; Choose one: A. a column of mixed rock types. B. a layer of specific rock types. C. a column of specific rock types. D. a layer of mixed rock types.

B. a layer of specific rock types

Identify the true statement: Choose one: A. Dating a sand grain in a sandstone gives the age of the sandstone's formation. B. All of the possible answers are correct. C. Dating a mineral within a metamorphic rock gives the age when the rock cooled below the closure temperatures of that mineral. D. Radiometric dating can be used only if some uranium is present in a rock.

C. Dating a mineral within a metamorphic rock gives the age when the rock cooled below the closure temperatures of that mineral

What does the term uniformitarianism mean? Choose one: A. The Earth's surface is unchanging. B. The physical processes on Earth today are different from those in the past. C. We can interpret the processes that formed ancient rock by examining the processes that form similar rock today. D. All of the possible answers are correct.

C. We can interpret the processes that formed ancient rock by examining the processes that form similar rock today

Which of the following was important in determining the cause of the K-Pg (Cretaceous-Paleogene) extinction? Choose one: A. iridium in K-Pg boundary clay B. shocked quarts in K-Pg boundary clay C. All of the possible answers are correct. D. glass spheres in K-Pg boundary rocks

C. all of the possible answers are correct

The boundary surface between two stratigraphic formations is called a Choose one: A. marker bed. B. nonconformity. C. contact. D. key bed.

C. contact

What type of unconformity occurs when sedimentary rocks overlie either igneous or metamorphic rocks? Choose one: A. angular unconformity B. disconformity C. nonconformity D. baked contact

C. nonconformity

Which of the following are fossil plants ? Choose one: A. pterosaurs and plesiosaurs B. gymnosperms and angiosperms C. graptolites and archaeocyathids D. trilobites and eurypterids

B. gymnosperms and angiosperms

What life-forms appeared during the Mesozoic Era? Choose one: A. swampy forests with tree-sized relatives of club mosses and ferns B. trilobites, mollusks, brachiopods, nautiloids, gastropods, and graptolites C. spiders, scorpions, insects, and crustaceans in both dry-land and freshwater habitats D. dinosaurs, mammals, birds, large swimming reptiles, and pterosaurs

D. dinosaurs, mammals, birds, large swimming reptiles, and pterosaurs

Banded iron formations (BIFs) formed Choose one: A. in alluvial fans at the base of the proto-Appalachian Mountains. B. during uplift of the Tibetan Plateau. C. beneath the Laurentide ice sheet. D. in the Proterozoic deep ocean.

D. in the Proterozoic deep ocean

Which of the following refers to fossils of early multicellular invertebrates that are 565 Ma to 620 Ma, like the one shown in the photo? Choose one: A. Rodinia B. cyanobacteria C. stromatolites D. Ediacaran fauna

D. Ediacaran fauna

How did tectonic conditions change during the Proterozoic Eon? Choose one: A. Broad, stable cratons formed in continental interiors. B. Sea levels rose to form shallow epicontinental seas. C. Convergence of crustal fragments with continents created exotic terranes. D. Rifting resulted in the formation of the Basin and Range Province of North America.

A. Broad, stable cratons formed in continental interiors

What caused the Himalayas and Alps to form ? Choose one: A. The Alps arose from Europe's collision with Asia; the Himalayas arose from Europe's collision with Africa. B. The Alps arose from Europe's collision with Africa; the Himalayas arose from India's collision with Asia. C. The Alps arose from Europe's collision with Africa; the Himalayas arose from India's collision with Africa. D. The Alps arose from India's collision with Asia; the Himalayas arose from Europe's collision with Africa.

B. The Alps arose from Europe's collision with Africa; the Himalayas arose from India's collision with Asia

During the Pleistocene Ice Age, Choose one: A. continental glaciers covered all of North America. B. the continental shelf west of Alaska was exposed and allowed migration of animals and people from Asia to North America. C. sea level rose because water was tied up as ice. D. continental glaciers in the northern hemisphere advanced and retreated only once.

B. The continental shelf west of Alaska was exposed and allowed migration of animals and people from Asia to North America

In the image below, what does the contact between the Unkar Group and Tapeats Sandstone represent? Choose one: A. an angular unconformity B. All of the possible answers are correct. C. missing time in the geologic record D. a surface formed by uplift and erosion of tilted older rock layers

B. all of the possible answers are correct

The continents that made up Pangaea began to split apart during the Choose one: A. late Paleozoic. B. late Triassic/early Jurassic. C. early Devonian. D. mid-Proterozoic.

B. late triassic/early Jurassic

Which of the following are principles used to determine the relative ages of geologic events? Choose one or more: A.original verticality B.uniformitarianism C.inclusions D.superposition E.geochronology F.lateral discontinuity

B. uniformitarianism C. inclusions D. superposition

A number of geologic principles allow geologists to observe the relative ages of rocks. Which of these images illustrates the principle of inclusions? Choose one or more: A.Image A B.Image B C.Image C D.Image D

B., Image B C. Image C

Why are geologists not able to date sedimentary rocks directly? Choose one: A. Sedimentary rocks are too coarse-grained to accurately date. B. Sedimentary rocks are older than their composite minerals. C. Sedimentary rocks are younger than their composite minerals. D. Sedimentary rocks are too fine-grained to accurately date

C. Sedimentary rocks are younger than their composite minerals.

Rodinia, Pannotia, and Pangaea are all names of Choose one: A. orogenies that occurred on the eastern margin of North America. B. extinct marine organisms. C. supercontinents. D. geologic time periods.

C. supercontinents

Which geologic time interval saw the first continents, the first life, and possibly the first plates? Choose one: A. Phanerozoic B. Hadean C. Proterozoic D. Archean

D. Archean

The map below shows the paleogeography of Earth during which time period? Choose one: A. Permian B. Cambrian C. Devonian D. Cretaceous

D. Cretaceous

Dipping sedimentary rock layers include a layer of basalt containing xenoliths of the overlying sedimentary rock. Which of the following statements must be true? Choose one: A. The basalt is older than the sedimentary rock layers above it. B. The sedimentary layers were deposited at an angle, creating the "dip" of the layers .C. The sedimentary layers were deposited on a basaltic lava flow. D. The basalt is a sill intruded into older sedimentary rock.

D. The basalt is a sill intruded into older sedimentary rock

The Late Devonian fossil shown in this image, Tiktaalik, is significant because it represents Choose one: A. the ancestor to all modern fish species. B. the first dinosaur species to evolve. C. one of the few species to survive the mid-Paleozoic extinction event. D. a transition from lobe-finned fish to amphibians that could walk on land.

D. a transition from lobe-finned fish to amphibians that could walk on land.

When a meteor exploded above Chelyabinsk, Russia, on February 15, 2013, the resulting shockwave broke windows and damaged buildings across the region. Which of the following was the result of an earlier, much larger meteorite impact? Choose one: A. formation of the Gulf of Mexico B. initiation of the Pleistocene Ice Age C. extinction of 95% of all life at the end of the Permian Period D. extinction of dinosaurs and many other life forms 65 million years ago E. catastrophic tsunami that destroyed coastal towns in Japan in March 2011

D. extinction of dinosaurs and many other life forms 65 million years ago

The first life forms; Choose one: A. required oxygen for respiration. B. probably occurred in oxygen-rich, shallow, warm ocean waters. C. date back to 4.3 billion years. D. may have been simple cells of bacteria or archaea living near hydrothermal vents.

D. may have been simple cells of bacteria of archaea living near hydrothermal vents

The oldest known mineral grain is a 4.4-million-year-old zircon crystal found in an ancient sandstone. Which of the following statements applies to this zircon grain? Choose one: The sandstone is 4.4 billion years old. It is impossible to determine the relative age of the sandstone given this information. The sandstone is older than 4.4 billion years old. The sandstone is younger than 4.4 billion years old.

The sandstone is younger then 4.4 billion years old

Stratigraphic correlation Choose one: A. relates layers in different places that are the same age, regardless of how different they look. B. has proven that the same sequence of rock types is present everywhere on Earth. C. cannot be performed globally because sedimentary rocks in different areas look so different. D. involves the matching of sedimentary layers to layers that look the same across the Earth.

jA. relates layers in different places that are the same age, regardless of how different they look

Select statements true of unconformities. Choose one or more: A.There are three major types of unconformities. B.Unconformities represent periods of erosion in the rock record. C.Unconformities represent periods of active deposition in the rock record. D.Unconformities represent periods of nondeposition in the rock record.

A.There are three major types of unconformities. B.Unconformities represent periods of erosion in the rock record. D.Unconformities represent periods of nondeposition in the rock record.

Consult the stratigraphic column for the Grand Canyon in your text or ebook.The A represents the Supai Group.The B represents the Redwall Limestone.The C represents the Mauv Limestone.The D represents the Tapeats Sandstone.The E represents the Unkar Group. Identify the places where there is an unconformable contact. Choose one or more: A.between A and B B.between B and C C.between C and D D.between D and E

A.between A and B B.between B and C D.between D and E

The great oxygenation event, which added abundant oxygen to the atmosphere beginning about 2.4 Ga, was due to the Choose one: A. emergence of multicellular organisms. B. evolution of photosynthetic organisms in oceans. C. appearance of Ediacaran fauna. D. appearance of photosynthetic plants on land.

B. Evolution of photosynthetic organisms in oceans.

How has Earth's atmosphere changed since it first formed? Choose one: A. There has been no change in Earth's atmosphere. B. The atmosphere contains much more nitrogen than the initial atmosphere. C. The atmosphere contains much less nitrogen than the initial atmosphere.

B. The atmosphere contains much more nitrogen than the initial atmosphere

Which of the following lists the three Phanerozoic eras in order from oldest to youngest? Choose one: A. Proterozoic, Mesozoic, Cenozoic B. Paleozoic, Mesozoic, Cenozoic C. Cenozoic, Mesozoic, Proterozoic D. Mesozoic, Archean, Cenozoic

B. Paleozoic, Mesozoic, Cenozoic