Deck 6: Sediment and Sedimentary Rocks

Question 1

Boulders include all rounded particles coarser than 2 mm in diameter.

Answer 1

False

Question 2

Lithification is the general term for the processes that convert loose sediment into a sedimentary rock.

Answer 2

True

Question 3

Sorting is the process by which sediment grains are selected and separated according to grain size.

Answer 3

True

Question 4

Sediments are unconsolidated, which means the grains are separate and unattached to one another.

Question 5

Sedimentary breccia is a sedimentary rock formed by cementation of coarse angular fragments of rubble.

Question 6

The principle of superposition states that in a stack of horizontal layers the oldest layer is on top.

Question 7

Clay is the finest sediment.

Question 8

Sedimentary rocks can form from the deposition of solid particles eroded from pre-existing rock or from the deposition of the hard parts of organisms.

Question 9

All evaporites have a crystalline texture.

Question 10

Chalk is not a sedimentary rock.

Question 11

Detrital sedimentary rocks form from cemented sedimentary grains that are fragments of a preexisting rock.

Question 12

The environment of deposition is determined by the location in which deposition occurs.

Question 13

Mud cracks form only in sediment exposed above water.

Question 14

Dolostone (dolomite) often forms from limestone.

Question 15

Sedimentary structures are features found in sedimentary rocks that provide clues that help interpret their transport and deposition.

Question 16

Plate tectonics do not influence the distribution of sedimentary rocks.

Question 17

Most shale contains both clay-sized and silt-sized particles.

Question 18

A sandstone with more than 25% sand-sized feldspar is an arkose.

Question 19

Most sediment is transported some distance by gravity, wind, water or ice.

Question 20

Limestone is a sedimentary rock composed mostly of the mineral calcite.

Question 21

Under what conditions is a sediment considered to be well-sorted?

A) when the grains contains a wide variety of grain sizes mixed together
B) when the grains contains just one general grain size and one mineral
C) when the grains are in individual layers
D) when the grains are nearly all the same size
E) when the grains contain just one or two general grain sizes

Question 22

_______ is an organic rock formed from the compression and alteration of plant remains such as leaves, twigs, and tree trunks.

A) Crystalline
B) Clastic
C) Bioclastics
D) Coal
E) Recycled

Question 23

______ is the shift to a tighter packing of sediment grains due to the weight of overburden.

A) Cementation
B) Recrystallization
C) Preservation
D) Compaction
E) Deposition

Question 24

The most common type of sedimentary rocks are ____.

A) inorganic
B) detrital
C) chemical
D) biochemical
E) carbonates

Question 25

Carbonate rocks contain the _____ ion as part of their chemical composition.

A) CaO₃^2-
B) CO₃^2-
C) CaCO₃^2-
D) limestone
E) Carbonate rocks do not contain ions.

Question 26

A(n) ___ is sandstone containing a significant amount of feldspar.

A) marble
B) quartz sandstone
C) graywacke
D) shale
E) arkose

Question 27

___ is a sedimentary rock formed by the cementation of coarse angular fragments of rubble.

A) Breccia
B) Conglomerate
C) Boulder rock
D) Arkose
E) Cataclastic

Question 28

A(n) ______ is sandstone in which more than 15% of the rock's volume consists of fine-grained matrix.

A) quartz sandstone
B) quartzite
C) graywacke
D) oolitic limestone
E) arkose

Question 29

______ are sedimentary rocks deposited by direct precipitation of minerals from water.

A) Hydro rocks
B) Clastic rocks
C) Chemical rocks
D) Aquatic rocks
E) Biologic rocks

Question 30

_____ is a term that describes a series of visible layers in sedimentary rock.

A) Units
B) Tables
C) Sheets
D) Planes
E) Bedding

Question 31

A sedimentary rock that consists of sediment grains bound by cement into a rigid framework is called _______.

A) crystalline
B) clastic
C) biochemical
D) organic
E) recycled

Question 32

______ is the general term for the processes that convert loose sediment into sedimentary rock.

A) Gluing
B) Hardening
C) Crystallization
D) Lithification
E) Stiffening

Question 33

____ is the process by which sediment grains are selected and separated according to grain size by agent of transportation.

A) Sorting
B) Grading
C) Distillating
D) Selection
E) Segregation

Question 34

The most common cements are _____ and ____.

A) hematite; limonite
B) dolomite; halite
C) calcite; quartz
D) olivine; pyroxene
E) feldspar; mica

Question 35

_____ is a coarse-grained sedimentary rock formed by the cementation of rounded gravel.

A) Breccia
B) Mega sandstone
C) Pebble rock
D) Boulder rock
E) Conglomerate

Question 36

A _____ is a layer of sedimentary rock with a vertical change in particle size, usually from coarse at the bottom to fine at the top.

A) patterned bed
B) cross bed
C) sorted bed
D) graded bed
E) schist

Question 37

Silt is mostly composed of ___ grains.

A) clay mineral
B) feldspar
C) quartz
D) mica
E) calcite

Question 38

In order of decreasing size (largest listed first), sedimentary grain sizes include __.

A) clay, sand, silt, and gravel
B) gravel, sand, clay, and silt
C) sand, gravel, silt, and clay
D) gravel, sand, silt, and clay
E) gravel, silt, sand, and clay

Question 39

Sand grains can be distinguished from silt grain by ____.

A) the gritty feel between the teeth
B) seeing the individual sand grains
C) composition of the grains
D) the gritty feel between the fingers.
E) only by a microscope

Question 40

_____ form(s) only in fine-grained sediments that are exposed to air.

A) Cross beds
B) Cleavage
C) Mudcracks
D) Bedding
E) Ripples

Question 41

___ are features found within sedimentary rock that formed during or shortly after deposition.

A) Bedding planes
B) Sedimentary structures
C) Laminations
D) Formations
E) Turbidity currents

Question 42

Rock salt is composed of the mineral ______.

A) calcite
B) trona
C) dolomite
D) halite
E) gypsum

Question 43

Peat is a brown lightweight unconsolidated deposit that ultimately can transform into ____.

A) bogolite
B) swampstone
C) crude oil
D) shale
E) coal

Question 44

The two primary types of carbonate sedimentary rocks are ___ and dolostone.

A) dolomite
B) gypsum
C) coal
D) limestone
E) sandstone

Question 45

______ forms from limestone when the calcium in calcite is partially replaced by magnesium.

A) Gypsum
B) Halite
C) Chert
D) Quartz
E) Dolomite

Question 46

A(n) ___ is a body of rock of considerable thickness that is large enough to be mappable and with characteristics that distinguish it from adjacent rocks.

A) layer
B) bed
C) blanket
D) formation
E) epoch

Question 47

A(n) ____ is a body of sediment deposited when a river flows into standing water, like a lake or sea.

A) formation
B) alluvial fan
C) delta
D) sandbar
E) intrusive deposit

Question 48

Sedimentary rock on ____ will enable planetary geologists to one day unravel its history.

A) the moon
B) Jupiter
C) Mars
D) Mercury
E) Io

Question 49

Continental environments include all of the following except __.

A) lake beds
B) river beds
C) glacial deposits
D) coral reefs
E) alluvial fans

Question 50

_____ are precipitated as a result of inorganic processes.

A) Chalks
B) Oolitic limestones
C) Coals
D) Calcic sandstones
E) Fossiliferous limestones

Question 51

_____ are massive deposits of limestone.

A) Turbidity flows
B) Alluvial fans
C) Deltas
D) Reefs
E) Lithosomes

Question 52

___ are polygonal patterns that form in very fine sediment as it dries.

A) Ripple marks
B) Cross beds
C) Burrows
D) Mud cracks
E) Graded beds

Question 53

___ is a hard, compact, very fine-grained sedimentary rock composed entirely of silica.

A) Tuff
B) Chalk
C) Chert
D) Travertine
E) Claystone

Question 54

In sandstone, a thick bed will often consist of a series of thinner inclined beds called ____.

A) laminations
B) ripple beds
C) graded beds
D) cross beds
E) tweed beds

Question 55

____ limestones have a clastic texture.

A) Fossiliferous
B) Bioclastic
C) Inorganic
D) Chemical
E) Oolitic

Question 56

_______ limestones are precipitated through the actions of organisms.

A) Hyaloclastic
B) Calciclastic
C) Bioclastic
D) Siliciclastic
E) Pyroclastic

Question 57

Asymmetrical _____ are produced by current flowing in a single direction.

A) wave marks
B) ridge marks
C) ripple marks
D) mullion marks
E) burrow marks

Question 58

The principle of ___ holds that, in a stack of horizontal layers the oldest layer is on the bottom and the layers become younger upward.

A) supposition
B) superposition
C) superannualation
D) original horizontality
E) bedding

Question 59

Oil and natural gas originate from _____ in marine sediments.

A) peat
B) the earth's interior
C) organic matter
D) coal
E) comet impacts

Question 60

_______ sediments are deposited or precipitated as a result of the actions of organisms.

A) Biochemical
B) Pyroclastic
C) Hyaloclastic
D) Siliciclastic
E) Calciclastic