Epsc 201 Chapter 6

Front 1

Sedimentary rocks can form

Back 1

By the cementing together of loose grains of preexisting rock

From shell fragments or carbon-rich relicts of plants

From shell fragments or carbon-rich relicts of plants

Front 2

Choose the proper listing of detritus terms, going from smallest to largest: slit, sand, pebbles, cobbles

Back 2

Mud, silt, sand, pebbles, cobbles

Front 3

Identify the TRUE statement:

- Conglomerates consist of a single grain size.

- Pieces of broken rock produced by physical weathering are collectively called clasts or detritus.

- A well-sorted clastic rock is made up of different-sized particles.

- An immature clastic rock has well-sorted, resistant grains.

Back 3

Pieces of broken rock produced by physical weathering are collectively called clasts or detritus.

Front 4

Which of the following features indicates the top of a sedimentary bed, or bed-surface, marker?

Back 4

Scour marks, fossil footprints, graded bedding, mud cracks

Front 5

T/F: Lithification is a general term used to describe all the physical, chemical, and biological processes that make a sedimentary rock from sediments.

Back 5

True

Front 6

A nonmarine clastic sedimentary rock composed of angular fragments surrounded by matrix is

Back 6

Breccia

Front 7

A clastic sedimentary rock with clay and silt-sized grains that breaks in thin sheets is called

Back 7

Shale

Front 8

Which term has nothing to do with the mineral calcite?

Back 8

Chert (made of the mineral quartz)

Front 9

Which of the following is an organic sedimentary rock originated as decaying plant matter is

Back 9

Coal

Front 10

Identify the TRUE statement:

- Both chert and limestone may have either chemical or biochemical origin.

- Chemical sedimentary rocks are crystalline in texture.

- Gypsum and halite are evaporite minerals.

- Flint, jasper, agate, and petrified wood are all varieties of the siliceous rock chert.

Back 10

All are correct.

Front 11

Ripple marks on a bedding plane

Back 11

Could suggest an ancient stream bed or a seashore

Front 12

What is the most logical past environment to have produced a deposit consisting of layers of unsorted, unstratified sedimentary clasts, clay-sized to boulder-sized?

Back 12

Glacial valley

Front 13

Geologists find a thick sequence of alternating shales and sandstones. The probable depositional environment and interpretation of these are:

Back 13

Deep-marine deposits near the continental shelf.

Front 14

The structure that may form where a stream enters a lake

Back 14

Has sloping foreset beds of gravel and sand

Has nearly horizontal silty bottomset beds on the lake floor

Has nearly horizontal topset beds composed of gravel

Is called a delta

Front 15

Which of the following geological features was NOT formed by sedimentary processes?

Back 15

Columbia river plateau

Front 16

Which of the following sedimentary features is the surest indicator that the past environment was deep water?

Back 16

Turbidites

Front 17

T/F: Sedimentary rocks differ from igneous rocks in that sedimentary rocks can never be crystalline in texture and igneous rocks always are crystalline.

Back 17

False

Front 18

The words weathering and erosion are synonyms; they can be used interchangeably.

Back 18

False

Front 19

Graywacke and conglomerate are examples of well-sorted rocks; claystone and siltstone are examples of poorly sorted rocks.

Back 19

False

Front 20

The formation of dolostone, due to the introduction of magnesium into limestone, is an example of diagenesis.

Back 20

True

Front 21

The word fluvial means lake.

Back 21

False

Front 22

Obvious sandstone beach deposits overlain by marine mudstone indicate transgression of the sea.

Back 22

True

Front 23

Diagenesis and metamorphism both alter the texture and mineral composition of rock; metamorphism is the higher temperature process.

Back 23

True

Front 24

A sequence of sedimentary beds, traceable across a region and distinctive enough to be recognized as a unit is called a stratigraphic formation.

Back 24

True

Front 25

Which of the following is NOT one of the major classes of sedimentary rocks?

Back 25

Intrusive (it's igneous)

Front 26

Formation of a clastic sedimentary rock involves five stages. Which of the following describes lithification?

Back 26

Compaction and cementation of loose particles to form solid rock

Front 27

As sediment is transported downstream, away from its point of origin, the particles found in the stream become

Back 27

Rounder, smaller, of greater resistance, better sorted by size

Front 28

Rocks formed dominantly from the calcium carbonate shells of marine organisms are classified as _____ and called _____.

Back 28

Biochemical and limestone

Front 29

Ripple marks, dunes, and cross bedding are useful indicators of

Back 29

Current direction

Front 30

A sedimentary basin that forms when continental lithosphere is stretched, causing down-dropped crustal blocks bordered by narrow mountain ranges and alluvial fans, is called a

Back 30

Rift basin

Front 31

Sediments in a passive-margin basin are primarily fluvially derived but can also include carbonates.

Back 31

True

Front 32

When sea level rises, the shoreline migrates inland, flooding the land and depositing coastal sediments over preexisting terrestrial sediments. This process is called

Back 32

Transgression

Front 33

33

Back 33

33