Chapter 6 geology

_____ basins contain the largest accumulation of marine sediments

Passive-margin

Diagnesis refers to ___

Physical and chemical alterations, including compaction and cementation, that occur as sediment is transformed into rocl

Which of the following is FALSE about regressions

They can occur when the climate warms and continental ice sheets melt.

What is the difference between the formations of chalk versus chert?

They made of different source materials

The breakdown of exposed rock into small fragments and dissolved ions is termed ____

Weathering

Which of the following processes invloves the creation of ions in solution >

Weathering

Glacial till is composed of ___ -sized particles

all

Beach sediments travel _____ the ocean during a transgression and __________ the ocean during a regression

away from; toward

Because the velocity of sediment settling (deposition) is positively related to grain size for waterbone sediments, fluvial deposits are more likely than glacial deposits to ___

be well sorted

Geologists call individual of sedimentary rocks ___, whereas several of them together are called ____

beds; strata

Cemented shells of marine organisms form which kind of sedimentary rock?

biochemical

Precipitation of gypsum due to evaporation of seawater produces which kind of sedimentary rock?

chemical

Lithified detritus (breakdown products of preexisting rocks) forms which kind of sedimentary rock?

clastic

Thick accumulations of sediments and fossils in the deep ocean tend to be _____ -sized due to the low amounts of energy.

clay

What type of sediment is typically found in the lake bottoms?

clay/mud

Lithification, the process by which sediments are turned into sedimentary rocks, includes ____

compaction and cementation

Which is the following is FALSE? As compared to arkose, quartz sandstone _____

contain more angular grains

Consult the figure below. Here distinct internal laminations are inclined at an angle to the boundary of the main sedimentary layers. This is termed ____

cross beds

Scour marks are indicator of _____

current flow

Topset, foreset, and bottomset beds together are indicative of ___ environments.

delta

A gravel bar in a river is an example of a landform created by ___

deposition

Large layers of cross-bedded sand can be indicative of a _____ environment

desert

When limestone becomes chemically altered so that half of the calcium atoms are replaced by magnesium, the resultant rock is termed ______.

dolostone

The elevation of a mountain is slowly decreased by weathering and ___

erosion

The removal of detritus from weathered rock at an outcrop is termed ____

erosion

Basins that form on the continental side of mountain ranges are called _____ basins

foreland

Clastic sedimentary rocks are primarily classified on the basis of _____

grain size

Lithification occurs ___

in the shallow subsurface

Compaction and cementation occur during ____

lithification

Two major sources of energy, coal and oil shale, are considered______ sedimentary rocks.

organic

If a geologist find thick accumulations of fossiliferous limestone, in what type of basin might they have been formed?

passive-margin

The primary difference between breccia and conglomerate is that conglomerate

possesses ore rounded grains than breccia

Cementation of sediments occurs when minerals ___ the spaces between sediment grains

precipitate in

Lake deposits tend to be composed of finely laminated mud stones, indicative of ____

quiet water

Shallow-marine deposits tend to have abundant fossils due to their proximity to _____

reefs

A well-sorted sandstone with asymmetric ripples was not likely deposited as sand by a(n)

river (far from source)

The majority of the rocks that are formed at the surface of the Earth are ___ rocks

sedimentary

A fine-grained clastic sedimentary rock that splits into thin sheets is ___

shale

Siltstone or mudstone containing marine fossils likely formed in a ____ environment.

shallow-marine

Biochemical limestones are dominated by carbonate mud and fragments of ____

skeletons of marine invertebrates made of calcite and aragonite

Sedimentary basins are often subject to __________ , which allows them to fill with thick accumulations of sediments

subsidence

As compared with metamorphism, diagenesis ___

take place at lower temperatures and pressures.

Sea level rises locally, and marine sediments are deposited on top of terrestrial sediments during events termed_______

transgressions

Grains become rounded primarily during ___

transportation

Which of the following does NOT reflect transport distance?

type of cement

If water is the transport mechanism of sediment, the grain size of sedimentary deposits most closely indicates the ____

velocity of the water at the moment the sediment settled to the bottom

If a geologist found preserved mud crack, he or she could conclude that the environment in which they formed ____ .

was once covered in wet mud

The image below shows a series of graded beds. How many full sets of graded beds are shown

3