Chapter 6 quiz & hw
h13: The accompanying diagram shows deposits formed by the rise and fall of sea level in a gently subsiding sedimentary basin. Which of the following statements accurately describe the events recorded by these rocks?
-The black shale was deposited in the deepest water. -The unconformity formed because the land surface was exposed and eroded. -Sea level was highest when the shale was deposited
h1: Sort the sedimentary rocks into the correct category.
Clastic: - pole with pebbles -one rock/brick Biochemical: -brown swirls w/ bush -penny Organic: -grassy mountain Chemical: -frozen lake -bullet
h2: Rank the following steps describing how a clastic sedimentary rock forms from its pre-existing parent rock.
First: -weathering -erosion -transportation -deposition -lithification Last:
q4: Which of the following statements is true? A. Pieces of broken rock produced by physical weathering are called clasts. B. A well-sorted clastic rock is made up of a wide range of particle sizes. C. Conglomerate consists of a single grain size. D. All well-rounded clasts are also spherical.
Pieces of broken rock produced by physical weathering are called clasts.
h4: Dunes form when currents (wind or water) move in one direction. Much like asymmetrical ripples, they have a gentle slope on the upstream side and a steep slope on the downstream side (slip face). Use the shape of this dune to select the statement that most accurately describes the wind direction in the image.
The wind was blowing from left to right
h12: Choose statements true of transgression and regression. Sort the statements as being true of either transgression or regression.
Transgression - Coastline migrates inland -Position of beach moves inland -Involved a relative rise in sea level Regression: - Involves a relative fall in sea level
q5: A nonmarine clastic sedimentary rock composed of angular pebbles surrounded by matrix would be
a breccia.
q20: The feature that may form where a stream enters a lake or ocean is called
a delta.
q23: 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 rift basin
h9: The image shows sedimentary rocks exposed in Death Valley National Park. In which of the following environments was this deposit was likely laid down?
alluvial fan
q19: The feature in the photo is an apron of gravel and sand deposited at the mouth of a streambed that is leaving the mountains and entering a flat plain. This type of feature is called
an alluvial fan
q1: Which of the following processes forms biochemical sedimentary rock? A. accumulation of mud on the seafloor B. deposition of quartz sand on a beach C. evaporation of seawater D. cementing together of shell fragments
cementing together of shell fragments
q8: Which of the following rock types contains the mineral quartz? A. chalk B. chert C. micrite D. fossiliferous limestone
chert
q2: Which of the following classes of sedimentary rock is produced by weathering and erosion of pre-existing rocks? A. intrusive B. chemical C. biochemical D. clastic
clastic
q17: The sandstone in this photo was most likely deposited in what type of environment? (Note the trees for scale.)
desert sand dunes
q22: Which of the following is a general term used to describe all the physical, chemical, and biological processes that make a sedimentary rock from sediments? A. diagenesis B. diamictite C. dolostone D. detritus
diagenesis
q25: South of the Himalayan mountain range, the crust of the Indian subcontinent has been bent downward and covered by a thick succession of sediment eroded from the mountains. This sedimentary basin is a type of
foreland basin
q13: The named intervals in this photo of the Grand Canyon are ________, and the yellow lines between them are called ________.
formations; contacts
q14: The current that deposited the sandstone in this photo was flowing
from left to right.
h5: This photomicrograph shows a bedding plane (yellow line) in a layer of sandstone. The blue areas are dyed epoxy (used to attach the rock to the microscope slide) that has filled in the pore space in the rock. The bedding in this specimen is primarily defined by a change in which of the following? A. grain size B. color C. type of cement D. mineralogy
grain size
q6: Which of the following minerals or rock types is associated with evaporite deposits? A. chert B. feldspar C. gypsum D. quartz
gypsum
h6: The image shows cross beds in the Navajo sandstone in Zion National Park. Note the person for scale near the bottom right corner of the image. Which of the following best describes the direction that the wind was blowing when these cross beds were formed?
left to right
h8: A delta consists of clastic sediment. The different grain sizes of sediments accumulate in different parts of the delta. Drag and drop the labels to indicate the appropriate clast sizes at each location. The arrow shows where the stream flows into the lake.
left to right: - - mostly grovel - sand and gravel - (top): open water - (bottom): silt and clay
h10: Carbonate reefs consist of several different sub-environments; each of these environments is shaped by different processes and thus accumulates different types of sediment. Drag and drop each sediment type or environment to the correct location on the diagram.
left to right: - calcite sand - lagoon - reef - reef face
h11: Match each rock with the environment in which it most likely formed.
left to right: - red beds - coal - marine sandstone - marine shale
h14: The image shows photographs of sandstones taken with a petrographic microscope (a special type of microscope used by geologists). Match the adjective describing grain shape with the appropriate specimen.
left to right: subrounded rounded angular
h3: The image shows photographs of sandstones taken with a petrographic microscope (a special type of microscope used by geologists). Match the description of sorting with the appropriate specimen.
left: moderately sorted middle: well sorted right: poorly sorted
h7: Place each clastic sedimentary rock into the correct environment of deposition.
mountain top: breccia green: conglomerate blue: shale orange: sandstone green/orange: arkose
q15: Which of the following features is a bed-surface marking, meaning that it appears on the surface of a bed as a result of events during or soon after sediment deposition? A. mud cracks B. cross beds C. graded bedding D. laminations
mud cracks
q11: Which of the following lists accurately reflects an increase in grain size from smallest to largest? A. sand, cobbles, pebbles B. silt, mud, sand C. sand, silt, pebbles D. mud, silt, sand
mud, silt, sand
q12: The organic sedimentary rock that is composed of mud-sized particles and partially decayed organic matter derived from plankton and algal remains is called
oil shale.
q18: In which of the following environments, or by which process, was this sedimentary structure most likely produced? A. in a deep-marine environment B. by a turbidity current C. All of the possible answers are correct. D. on a floodplain
on a floodplain
q3: Coal is a form of
organic sedimentary rock.
q21: A deposit contains very little sand and mud, but instead a lot of broken-up carbonate shells of marine organisms. What was the likely depositional environment?
reef
q16: Which of the following sedimentary structures indicates that the sediments were deposited by a moving fluid? A. mud cracks B. fossil footprints C. ripple marks D. laminations
ripple marks
q9: Formation of a clastic sedimentary rock involves five stages. Of these stages, erosion is the
separation of rock or regolith from its substrate.
q7: A clastic sedimentary rock with clay and silt-sized grains that is finely laminated and breaks into thin sheets is called
shale
q10: As clastic sediment is transported downstream, away from its point of origin, what happens to the clasts?
they become smaller in size
q24: In this image, the fact that shoreline beach deposits occur on top of terrestrial swamp and floodplain deposits indicates that ________ has occurred.
transgression
