Chapter 15

Question 1

pressure

Answer 1

equal squeezing from all sides

Question 2

compression

Answer 2

squeezing or squashing in a specific direction

Question 3

tension

Answer 3

stretching or pulling apart

Question 4

shear

Answer 4

which happens when one part of a material moves relative to another part in a direction parallel to the boundary between the parts

Question 5

deformation

Answer 5

displacement of rocks on sliding surfaces called faults

Question 6

folds

Answer 6

bending or warping of layers to produce arch-like or trough-like shapes
Overall change in the shape of a rock body by thickening or thinning

Question 7

geologic structures

Answer 7

products of deformation such as faults, folds, and foliations

Question 8

foliation

Answer 8

a fabric caused by the alignment of platy or elongate minerals

Question 9

block diagram

Answer 9

3D representation of a region of the crust that depicts the configuration of structures on the ground as well as on one or two vertical into the ground

Question 10

geologic map

Answer 10

represents the earth’s surface as it would appear looking straight down from above, showing the boundaries between rock units and where structures intersect the Earth’s surface.

Question 11

Cross- section

Answer 11

represents the configuration of structures as seen in a vertical slice through the Earth.

Question 12

contact

Answer 12

the boundary between two geologic units

Question 13

trace

Answer 13

line representing the intersection of a planar feature with the plane of a map or cross section

Question 14

stratigraphic formation

Answer 14

a sequence of sedimentary and/ or volcanic layers that has a definable age and can be identifies over a broad region

Question 15

unit can be

Answer 15

a stratigraphic formation, intrusive igneous body, interval of a specified type of metamorphic rock

Question 16

Types of contacts

Answer 16

Intrusive contact
Conformable contact
unconformable contact
fault contact

Question 17

Intrusive contact

Answer 17

boundary surface of an intrusive igneous body

Question 18

conformable contact

Answer 18

boundary between successive beds, sedimentary formations, or volcanic extrusions in a continuous stratigraphic

Question 19

unconformable contact

Answer 19

occurs where a period of erosion and or deposition has interrupted deposition

Question 20

fault contact

Answer 20

is where two units are juxtaposed across fault

Question 21

attitude

Answer 21

the orientation of any planar geologic feature

Question 22

strike

Answer 22

first number, the compass direction of a horizontal line drawn on the surface of the feature

Question 23

dip

Answer 23

second number, the angle of tilt or the angle of slope of the bed, measured relative to horizontal surface

Question 24

quadrant notation

Answer 24

when the strike is written as some angle relative to north

Question 25

azimuth notation

Answer 25

writing strike as a three-digit number

Question 26

map view

Answer 26

the top of a block

Question 27

cross-section view

Answer 27

the side of a block

Question 28

anticline

Answer 28

arch-like fold whose layers dip toward the base of the trough layers of rock upward

Question 29

fold limb

Answer 29

side of a fold

Question 30

fold hinge

Answer 30

the line that separates the two limns

Question 31

nonplunging fold

Answer 31

hinge of a fold is horizontal

Question 32

plunging fold

Answer 32

high of a fold has a tilt

Question 33

basin

Answer 33

a bowl shaped structure

Question 34

dome

Answer 34

overturned bowl

Question 35

fault displacement

Answer 35

one body of rock slides past another

Question 36

hanging wall

Answer 36

rock above the fault surface

Question 37

footwall

Answer 37

rock below the fault surface

Question 38

strike-slip faults

Answer 38

tend to be nearly vertical, and displacement on them is horizontal

Question 39

dip-slip faults

Answer 39

displacement is parallel to the dip direction on the fault

Question 40

Reverse fault

Answer 40

hanging wall moves up the dip

Question 41

normal fault

Answer 41

moves down the dip

Question 42

thrust fault

Answer 42

if a reverse fault has a gentle dip or curved

Question 43

unconformity

Answer 43

contact that represents a period od non-deposition and or erosion

Question 44

disconformity

Answer 44

bedding above and below the unconformity is parallel

Question 45

nonconformity

Answer 45

strata are deposited on a "basement" of intrusive igneous and or metamorphic rock

Question 46

angular conformity

Answer 46

orientation of the beds above the unconformity is not the same as that below

Question 47

Tabular intrustion

Answer 47

roughly parallel margins include dikes which cut across preexisting layers and sills- sheet-like intrusions

Question 48

Plutons

Answer 48

irregularly shaped, blob-shaped, or bulb-shaped intrusions

Question 49

line of section

Answer 49

map view along which you want to produce the cross-section