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