Chapter 16

Question 1

Geology

Answer 1

study of the earth’s dynamic history. Geologists study and analyze rocks and the features and processes of the earth’s interior and surface.

Question 2

Core

Answer 2

Inner zone of the earth. It consists of a solid inner core and liquid outer core.

Question 3

Mantle

Answer 3

zone of the earth’s interior between its core and its crust.

Question 4

Crust

Answer 4

solid outer zone of the earth. It consists of oceanic crus and continental crust.

Question 5

Convection cells/currents

Answer 5

move large volumes of rock and heat in loops within the mantle like a giant conveyer belt.

Question 6

mantle plumes

Answer 6

mantle rock flows slowly upward in a column, like smoke from a chimney on cold, calm morning.

Question 7

tectonic plates

Answer 7

various-sized areas of the earth’s lithosphere that move slowly around with the mantle’s flowing asthenosphere. Most earthquakes and volcanoes occur around the boundaries of these plates.

Question 8

lithosphere

Answer 8

outer shell of the earth, composed of the crust and the rigid, outermost part of the mantle outside the asthenosphere; material found in earth’s plates.

Question 9

continental drift

Answer 9

throughout the earth’s history, continents have split and joined as plates have very slowly drifted thousands of kilometers back and forth across the planet’s surface.

Question 10

divergent plate boundary

Answer 10

area where earth’s lithospheric plates move apart in opposite directions.

Question 11

convergent plate boundary

Answer 11

area where earth’s lithospheric plates are pushed together.

Question 12

transform fault

Answer 12

area where the earth’s lithospheric plates move in opposite but parallel directions along a fracture (fault) in the lithosphere.

Question 13

erosion

Answer 13

process or group of processes by which loose or consolidated earth materials and dissolved, loosened, or worn away and removed from one place and deposited in another.

Question 14

weathering

Answer 14

physical and chemical processes in which solid rock exposed at earth’s surface is changed to separate solid particles and dissolved material, which can then be moved to another place as sediment.

Question 15

physical/mechanical weathering

Answer 15

a large rock mass is broken into smaller fragments.

Question 16

frost wedging

Answer 16

water collects in pores and cracks of rock, expands upon freezing, and splits off pieces of the rock.

Question 17

chemical weathering

Answer 17

one or more chemical reactions decompose a mass of rock.

Question 18

biological weathering

Answer 18

the conversion of rock or minerals into smaller particles through the action of living.

Question 19

earthquake

Answer 19

shaking of the ground resulting from the fracturing and displacement of rock, which produces a fault, or from subsequent movement along the fault.

Question 20

richter scale

Answer 20

a measurement used by scientists to determine the magnitude of earthquakes.

Question 21

aftershocks

Answer 21

gradually decrease in frequency over a period of up to several months.

Question 22

foreshocks

Answer 22

from seconds to weeks before the main shock.

Question 23

tsunamis

Answer 23

coastal areas can be severely damaged by earthquakes at sea that can generate huge water waves. aka tidal waves, have nothing to do with tides.

Question 24

volcano

Answer 24

vent or fissure in the earth’s surface through which magma, liquid lava, and gases are released into the environment.

Question 25

fissure

Answer 25

a central vent or long crack in the earth’s surface.

Question 26

ejecta

Answer 26

debris ranging from large chunks of lava rock to ash that may be glowing hot.

Question 27

mineral

Answer 27

any naturally occurring inorganic substance found in the earth’s crust as a crystalline solid.

Question 28

rock

Answer 28

any material that makes up a large, natural, continuous part of the earth’s crust.

Question 29

igneous rock

Answer 29

rock formed when molten rock material (magma) wells up from the earth’s interior, cools, and solidifies into rock masses.

Question 30

sedimentary rock

Answer 30

rock that forms from the accumulated products of erosion and in some cases from the compacted shells, skeletons, and other remains of dead organisms.

Question 31

metamorphic rock

Answer 31

rock produced when a preexisting rock is subjected to high temperatures (which may cause it to melt partially), high pressures, chemically active fluids, or a combination of these agents.

Question 32

rock cycle

Answer 32

largest and slowest of the earth’s cycles, consisting of geologic, physical, and chemical processes that form and modify rocks and soil in the earth’s crust over millions of years.

Question 33

nonrenewable mineral resource

Answer 33

a concentration of naturally occurring nonrenewable material in or on the earth’s crust that can be extracted and processed into useful materials at an affordable cost.

Question 34

ore

Answer 34

part of a metal-yielding material that can be economically and legally extracted at a given time. An ore typically contains two parts: the ore mineral, which contains the desired metal, and waste mineral material (gangue).

Question 35

identified resources

Answer 35

deposits of a particular mineral-bearing material of which the location, quantity, and quality are known or have been estimated from direct geological evidence and measurements.

Question 36

reserves

Answer 36

resources that have been identified and fro which a usable mineral can be extracted profitably at present prices with current mining technology.

Question 37

undiscovered resources

Answer 37

potential supplies of a particular mineral resource, believed to exist because of geologic knowledge and theory, although specific locations, quality, and amounts are unknown.

Question 38

surface mining

Answer 38

removing soil, subsoil, and other strata and then extracting a mineral deposit found fairly close to the earth’s surface.

Question 39

subsurface mining

Answer 39

extraction of a metal ore or fuel resource such as coal from a deep underground deposit.

Question 40

overburden

Answer 40

layer of soil and rock overlaying a mineral deposit. Surface mining removes this layer.

Question 41

spoils

Answer 41

unwanted rock and other waste materials produced when a material is removed from the earth’s surface or subsurface by mining, dredging, quarrying, and excavation.

Question 42

open-pit mining

Answer 42

removing minerals such as gravel, sand, and metal ores by digging them out of the earth’s surface and leaving an open pit.

Question 43

dredging

Answer 43

type of surface mining in which chain buckets and draglines scrape up sand, gravel, and other surface deposits covered with water. It is also used to remove sediment from streams and harbors to maintain shipping channels.

Question 44

area strip mining

Answer 44

type of surface mining used where the terrain is flat. An earthmover strips away the overburden, and a power shovel digs a cut to remove the mineral deposit. After removal of the mineral, the trench is filled with overburden and a new cut is made parallel to the previous one. This process is repeated over the entire site.

Question 45

contour strip mining

Answer 45

form of surface mining used on hilly or mountainous terrain. A power shovel cuts a series of terraces into the side of a hill. An earthmover removes the overburden, and a power shovel extracts the coal, with the overburden from each new terrace dumped onto the one below.

Question 46

mountaintop removal

Answer 46

type of surface mining that uses explosives, massive shovels, and even larger machinery called draglines to remove the top of a mountain to expose seams of coal underneath a mountain.

Question 47

Surface Mining Control and Reclamation Act of 1977

Answer 47

requires mining companies to restore most surface-mined land so it can be used for the same purpose as before it was mined.

Question 48

Subsidence

Answer 48

slow or rapid sinking of part of the earth’s crust that is not slope-related.

Question 49

acid mine drainage

Answer 49

when rainwater seeping through a mine or mine wastes carries sulfuric acid to nearby streams and groundwater.

Question 50

gangue

Answer 50

one of the two components of ore, and it is the waste material.

Question 51

tailings

Answer 51

removing the gangue from the ores produces piles of waste.

Question 52

smelting

Answer 52

process in which a desired metal is separated from the other elements in an ore mineral.

Question 53

depletion time

Answer 53

the time it takes to use a certain fraction, usually 80% of the known or estimated supply of a nonrenewable resource at an assumed rate of use. Finding and extracting the remaining 20% usually costs more than it is worth.

Question 54

General Mining Law of 1872

Answer 54

was designed to encourage mineral exploration and the mining of hardrock minerals on U.S. public lands and to help develop the then sparsely populated West.