40 questions
Shale refers to a rock formed from:
sand sized material
plant remains
clay minerals
carbonate
Which one of the following is a biochemical sedimentary rock?
sand sized material
coal
shale
conglomerate
A clastic rock is:
a rock formed from the cementation of transported grains
a rock formed from evaporation of sea water
transformed by heat into limestone
transformed by pressure into limestone
Which one of the following features is NOT associated with sedimentary rocks?
bedding
foliation
fossils
all may be associated with sedimentary rocks
Which of the following types of sediments are most abundant?
coarse clastics
fine clastics
chemical
biochemical
The tendency for variations in current velocity to segregate sediments on the basis of particle size is called _____.
lilthification
compaction
metamorphism
sorting
Which of the following types of currents can transport sand grains?
rivers
wind
ocean waves
all of the above
What is the right answer for box A?
Breccia
Chert
Shale
Halite
In which of the following sedimentary environments would you expect the sand deposits to be poorly sorted?
alluvial
desert
beach
glacial
Which of the following lists is written in order of decreasing particle size?
siltstone, sandstone, conglomerate
conglomerate, sandstone, siltstone
sandstone, conglomerate, siltstone
sandstone, siltstone, conglomerate
What is the difference between a breccia and a conglomerate?
breccias are coarse grained and conglomerates are fine grained
breccias have angular fragments and conglomerates have rounded fragments
breccias have rounded fragments and conglomerates have angular fragments
conglomerates are coarse grained and breccias are fine grained
What is the right answer for box B?
Breccia
Chert
Conglomerate
Halite
What is the porosity of newly deposited mud?
> 50%
between 25% and 50%
between 5% and 25%
less than 5%
In which of the following sedimentary environments would you least expect to find gravel?
active margin beach
alluvial fans
glacial
deep marine
The most common lithification process for fine clastics is _______ .
cementation
compaction
dissolution
recrystallization
A feldspar-rich sandstone is called a(n) ________ .
arkose
litharenite
quartz arenite
shale
What is the right answer for box H?
Breccia
Chert
Conglomerate
Halite
The grain size of clastic sedimentary rocks may provide clues to the environment in which the sediments were deposited.
true
false
What is the sedimentary environment represented by #6?
Deep Sea Floor
Barrier Island
Glaciers
Abyssal Fan
With time, sediment transported by a fluvial system ___________.
becomes rounded
becomes smaller
becomes rounded and smaller
none of these
Name the sorting type for I
very poorly sorted
moderately sorted
well sorted
poorly sorted
Sorting is a function of the transport history of the detritus
true
false
A poorly-sorted sediment is composed of clasts that mainly fall in one class on the Wentworth scale.
true
false
Clay minerals commonly form as breakdown products of feldspars and other silicate minerals.
true
false
What is the sedimentary environment represented by #16?
Lacustrine
Barrier Island
Glaciers
Abyssal Fan
Clay is the most common mineral seen in silt deposits.
true
false
The term arenite, which is a sandstone with less than 75% matrix.
true
false
The topsoil is the region of most intense biological activity: insects, worms, and other animals burrow through it and plants stretch their roots down into it.
true
flase
In sedimentary geology, fabrics may provide information on both the orientation and magnitude of the strains that have affected a particular piece of deformed rock
true
flase
Clast sphericity is an inherited feature, that is, it depends on the shapes of the fragments which formed during weathering
true
false
Radiolarians are phytoplankton and diatoms are zooplankton
FALSE
TRUE
The dense internal structure of interlocking microquartz grains and fibres makes chert the weakest sedimentary rock.
TRUE
FALSE
Sedimentary rocks that contain at least 15% iron are referred to as ironstones.
TRUE
FALSE
Sediments and sedimentary rocks with a high proportion of organic matter are termed siliceous .
FALSE
TRUE
Mudrocks that contain a high proportion of organic material that can be driven off as a liquid or gas by heating are called oil shales.
TRUE
FALSE
The interaction of the sedimentary material with the transporting media results in the formation of bedforms.
FALSE
TRUE
Wind blowing over the land can pick up dust and gravel and carry it over large distances.
TRUE
FALSE
Turbulent flow occurs in debris flows, in moving ice and in lava flows, all of which have low kinematic viscosities.
TRUE
FALSE
Water flows are only laminar at very low velocities or very shallow water depths.
TRUE
FALSE
The settling velocity of particles in a fluid is determined by the size of the particle, the difference in the density between the particle and the fluid, and the fluid viscosity.
TRUE
FALSE