Geol 100 Exam 2

Which of the following environments would likely have clasts smaller than sand? a) a weak current b) steep slopes c) dunes formed by wind d) all of these

a.) a weak current

1. The image shows Stone Mountain in Georgia, a feature made of granite that was uncovered by erosion that removed the overlying and flanking softer rocks. What is the best name for this feature? a) An erosional remnant b) A mesa c) A thrust fault d) An anticline

a.) an erosional remnant

1. In which of the following environments is the lithosphere likely to be thinnest? a) beneath a mid-ocean ridge b) beneath a typical part of the abyssal plain c) a tectonically active continental margin d) the interior of a continent away from plate boundaries

a.) beneath a mid-ocean ridge

1. Which principle of relative age dating can be used to determine when the river formed on the landscape? a) cross-cutting relations b) inclusions c) original horizontality d) superposition

a.) cross-cutting relations

The natural cements that hold clasts together precipitate in the empty pore spaces after compaction. Those precipitates come from: a) water containing dissolved materials b) outward growth of the original clasts c) the alignment of clay particles

a.) water containing dissolved materials

1. Unit C is present in the left column but not the right column because: a) rocks in the right column were tilted and eroded b) it was not deposited or was eroded away c) it has different kinds of fossils than rocks in the right column d) all of these

b.) it was not deposited or was eroded away

1. This figure shows a disconformity between an upper dark layer (being deposited by the sea) and a lower light-colored layer. What happened to form this disconformity? a) The lower layers were tilted and untilted before deposition of the upper layers. b) The boundary between the two units indicates that for a time there was either erosion or no deposition. c) The lower limestones were converted into another rock type by seawater. d) The upper layer must have been deposited by volcanic eruptions.

b.) the bpundary between the two units indicates that for a time ther was eiather erosion or no deposition

1. This photograph shows an upper light-colored conglomerate and a lower dark basalt. Which of the following statements is true? a) the conglomerate is older because it overlies the dark basalt b) the conglomerate is younger because it contains clasts of the dark basalt c) the basalt is younger because it is crosscut by fractures filled with conglomerate d) none of these

b.) the conglomerate is younger because it contains clasts of the dark basalt

1. What type of metamorphic feature is shown in this photograph? a) cleavage in slate b) hornfels c) foliation in banded gneiss d) thrust fault

c.) foliation in banded gneiss

1. What were some of the earliest forms of life on Earth? a) land plants and insects b) corals and other bottom-dwelling sea creatures c) microscopic creatures that built mound-shaped structures called stromatolites d) sharks

c.) microscopic creatures that built mound-shaped structures called stromatolites

1. What type of fault is shown in this figure? a) dip-slip fault b) normal fault c) strike-slip fault d) reverse fault

c.) strike-slip fault

1. What will happen during movement on these normal faults? a) the crust will thicken and the region will be uplifted b) the crust will thin and the region will be uplifted c) the fault blocks will rotate in the same direction, like books sliding on a shelf d) the blocks will be uplifted or downdropped with only minor rotation

c.) the fault blocks will rotate in the same direction, like books sliding on a shelf

1. Why is there a basin associated with some thrust faults? a) thrust faults thin the crust and cause subsidence b) thrust faults form passive margins c) thrust sheets depress the crust in front of the thrust d) thrust sheets form a continent rift

c.) thrust sheets depress the crust in front of the thrust

1. If a rock started with 1,000 atoms of a parent but now contains 250 atoms, how many half lives have passed? a) .25 half lives b) .5 half lives c) 1 half life d) 2 half lives e) there is no way to tell

d.) 2 half lives

1. Which of the following forms different layers from season to season and can be used to determine how many years the layers represent? a) tree rings b) layers in ice cores c) varves d) all of these

d.) all of these

1. If you wanted to locate hot spots on Earth, which of the following would NOT be good place to look? a) the volcanically active end of a linear island chain b) clusters of volcanically active islands c) Hawaii and the Galapagos d) all of these would be good places

d.) all of these would be good places.

1. Regional elevation can be increased by: a) thinning the crust b) normal faulting c) eroding material from the top d) heating the crust and mantle

d.) heating the crust and mantle

1. What type of stress could form the fault in this figure? a) confining pressure b) horizontal tension c) vertical tension d) horizontal compression e) any of these

d.) horizontal compression

What is the best explanation for the shape of these clasts? a) they are composed of relatively soft, soluble materials b) they accumulated on a steep slope c) they have been moved by the wind and rounded by blowing sand in sand dunes d) they have been transported a significant distance

d.) they have been transported a significant distance

1. This figure shows two sections of rocks. What is the youngest unit? a) unit 1 b) unit 4 c) unit 6 d) unit 9 e) none of these

d.) unit 9

1. Which of the following may affect crustal thickness? a) Type of crust (continental or oceanic) b) Deformation (like compression or stretching) c) Erosion d) Deposition or burial by volcanic rocks e) All of these affect crustal thickness

e.) all of these affect crustal thickness

1. Which of the following processes/situations may alter regional land elevation? a) Intrusions of magma b) Thrust faulting or normal faulting c) Erosion or deposition d) Heating or cooling e) All of these processes/situations can alter regional land elevation

e.) all of these processes/ situations can alter regional land elevation

1. Which area shown on the map has the greatest seafloor depth? a) (T) trench b) (P) passive margin c) (R) oceanic ridges

a.) (T) trench

1. What is true of regional elevations across North America? a) Elevations tend to be higher toward the west and decrease toward the east. b) Elevations are highest in the Appalachian Mountains. c) Elevations are lowest in the Great Plains. d) Elevations do not change, when progressing from west to east.

a.) elevations tend to be higher toward the west and decrease toward the east

How does gypsum form? a) evaporation of water in a lake or sea b) accumulation of microscopic organisms composed of calcium carbonate c) precipitation from seawater early in Earth's history d) accumulation of silica-rich organisms or mixing of seawater and groundwater

a.) evaporation of water in a lake or sea

1. The principle that regional elevations adjust to the types and thicknesses of rocks at depth is known as: a) isostasy b) superposition c) elastic rebound d) equanimity

a.) isostasy

1. A local mountain created by volcanism: a) may be high in elevation but is not accompanied by a regional increase in crustal thickness b) is always accompanied by a regional increase in crustal thickness c) is always low in elevation and therefore has no need for increase in crustal thickness d) cannot be a shield-type volcano

a.) may be in elevation but is not accompanies by a regional increase in crustal thickness

1. Which of these numbered features is an accretionary prism? a) 1 b) 2 c) 3 d) 4e) 5

b.) 2

1. The impressions of fossil shells in this photograph probably indicate that the rock was deposited: a) by the wind b) in the sea c) in a dry climate d) in a forest

b.) in the sea

Which of the following attributes does NOT apply to these sediments? a) angular clasts b) cobbles and boulders c) well sorted d) composed of gravel

c.) Well sorted