OCN 150 Chapter 4
A drill ship used to confirm the existence of seafloor spreading by discovering: -the age of the ocean floor was oldest the farther away from the mid-ocean ridge it was -Sediment thickness increased with distance from the mid-ocean ridge -Earth's magnetic field polarity reversals were recorded in ocean floor rocks
Deep Sea Drilling Project (DSDP)
The calcite compensation depth (CCD) represents the depth where wave action ceases to form calcareous oolites. True/False
False
__________ are protozoans that use an external food source and are found in warmer waters
Formanifers
When sampling sediment, generally every deposit is a mixture of different sediment types. However, different sediment types twnd to dominate and this allows scientists to identify them as lithogeneous, biogeneous, hydrogeneous, or cosmogeneous (True,False)
True
Shallow water on the continental shelf has ________ sediments (neritic/pelagic)
neritic
Pelagic lithogeneous sediment is formed from ___________ ___, wind-blown dust, and fine-grained material transported by deep ocean currents
volcanic ash
Which of the following is the most fine-grained sediment? a) beach sand b) cobbles on the beach c) silt from a quiet lagoon d) a pebble beach e) abyssal clay
e) abyssal clay
_________ ooze is made up of coccolithophores and formanifers
Cacareous
_______ ooze forms under warm surface waters in low latitudes
Calcareous
the ____________________ is where calcite dissolves readily past a certain depth.
Calcite Compensation Depth
What is the correct order of grain size from the Wentworth Scale from smallest to largest?
Clay, Silt, Sand, pebble, Boulder
_________ are photosynthetic algae that form "rock chalk" and are 10-100 times smaller than diatoms. found in warmer waters
Coccolithophores
Where does most of the lithogeneous sediment end up?
Continental Margin
A sediment that is derived from extraterrestrial sources. (lithogeneous, biogeneous, hydrogeneous, cosmogeneous)
Cosmogeneous
The skeletal remains (tests) dissolved in sea water at a certian depth that determines the distribution of biogeneous sediment
Destruction
A hydrogeneous sediment that forms when there is restricted open ocean circulation and where evaporative rates are high. They are minerals that form when sea water evaporates
Evaporites
Because they tend to move downslope, most lithogenous sediments are deposited in abyssal plains. True/False
False
Black volcanic beach sand is a type of hydrogenous sediment. True/False
False
A hydrogeneous sediment that are small calcite spheres that have layers like an onion and form in shallow tropical waters where there is a lot of CaCO3. (egg rocks)
Oolites
Sediment that contains quartz sand, quarts silt, clay, volcanic ash, and rock fragments (lithogeneous, biogeneous, hydrogeneous, cosmogeneous)
Lithogeneous
the depth in the ocean at which the pressure is high enough and the amount of carbon dioxide in deep ocean waters is great enough to begin dissolving CaCO3
Lysocline
Large enough to be seen without a microscope. Includes shells, bones, and teeth of large organisms. Rare in deep sea
Macroscopic biogeneous sediment
A hydrogeneous marine sediment that is rounded, fist-sized lumps of manganese, iron, adn other metals
Manganese nodules
A hydrogeneous sediment that is associated with hydrothermal vents and are found throughout the ocean floor due to sea floor spreading
Metal Sulfides
Only can be seen under a microscope. More abundant than macroscopic biogeneous sediment. made by microscopic organisms
Microscopic Biogeneos sediment
Naturally occurring compound
Mineral
_______ sediment covers about 1/4 of the sea floor, is in shallow water, is dominantly lithogeneous, and typically deposited quickly. (neritic, pelagic)
Neritic
the build up of tests on the ocean floor
Ooze
Deep water on the abyssal planes has __________ sediments (neritic/pelagic)
Pelagic
________ sediments cover about 3/4 of the sea floor, is found in deeper water, has fine grains, is deposited slowly, and has more biogeneous material. (neritic, pelagic)
Pelagic
A hydrogeneous marine sediment occurs as a coating on rocks and nodules on the continental shelf. They occur beneath area of very high productivity
Phosphates
Sediment that contains a variety of different sized particles are _________ sorted
Poorly
__________ occurs when there is a change in conditions
Precipitation
The number of organisms in the surface water above the ocean floor that determines the distribution of biogeneous sediment
Productivity
Distribution of biogeneous sediment is determined by __________, ____________, and ____________
Productivity, destruction, dilution
What is the most stable, durable, and abundant mineral?
Quartz
__________ are protozoans that use external food, they are often planktonic, and symmetrical. Found in cooler waters.
Radiolarians
eroded particles and fragments of dirt, dust, and other debris that have settled out and accumulated on the ocean floor
Sediments
Which ooze accumulates in areas of high productivity?
Siliceous
________ ooze forms under cool surface waters in high latitudes
Siliceous
_________ ooze is made up of diatoms and radiolarians.
Siliceous
Measure of the uniformity of grain sizes
Sorting
________ and ____ _______ are the two main types of cosmogeneous sediment.
Spherules, meteor debris
Neritic carbonate deposits found in warm, shallow-ocean, high salinity water. They are sedimentary rocks that have fine layers of carbonate and cyanobacteria.
Stromatolites
Which of the following statements about the Deep Sea Drilling Project (DSDP) is FALSE? a) The DSDP drilled to the center of Earth and confirmed that the outer core is composed of liquid iron-nickel material. b) The DSDP confirmed that the age of the ocean floor increases with distance from the axis of the mid-ocean ridge. c) The DSDP confirmed that sediment thickness increases with distance from the axis of the mid-ocean ridge. d) The DSDP confirmed that Earth's magnetic field polarity reversals are recorded in sea floor rocks.
a) The DSDP drilled to the center of Earth and confirmed that the outer core is composed of liquid iron-nickel material.
Populations of microscopic marine organisms in ocean surface waters closely match their abundance in sediments on the ocean floor, even though it takes 10 to 50 years for an individual particle to sink to deep-ocean depths. What accounts for this pattern? a) concentration of the particles in fecal pellets. b) accumulation in manganese nodules c) movement of horizontal ocean currents d) transportation by turbidity currents e) rain falling in the ocean
a) concentration of the particles in fecal pellets.
Lithogenous sediments are ___________. a) made of material derived from pre-existing rock material b) primarily made up of manganese nodules c) derived from outer space d) composed of the hard remains of once-living organisms e)composed of dissolved material from seawater
a) made of material derived from pre-existing rock material
Which of the following is the most abundant component by weight for deep-ocean sediments? a) evaporites b) Clay c) Sand d) gravel e) fecal pellets
b) Clay
How is most sediment transported from the continental shelf out to the continental rise? a) in underwater streams that flow along the sea floor b) by turbidity currents c) by hitching a ride with deep-dwelling marine life d) by sinking far offshore once it gets waterlogged e) through winds
b) by turbidity currents
Which of the following marine organisms lives in cold, polar waters? a) coccolithophores b) diatoms c) foraminiferas d) radiolarians
b) diatoms
Calcareous ooze is associated with ________ surface water conditions, and siliceous ooze is associated with ________ surface water conditions. a) warm; warm b) warm; cool c) cool; warm d) cool; cool
b) warm; cool
Sediments that contains Silica and Calcium Carbonate (lithogeneous, biogeneous, hydrogeneous, cosmogeneous)
biogeneou
Sediments that were brought to the ocean by cold surface waters (diatoms and radiolarians), warm surface waters (coccolithophores and formanifers), microscopic shells, and coral reefs (lithogeneous, biogeneous, hydrogeneous, cosmogeneous)
biogeneous
What is the second most abundant sediment? (lithogeneous, biogeneous, hydrogeneous, cosmogeneous)
biogeneous
Which of the following statements about biogenous oozes is FALSE? a) The organisms that form biogenous oozes live in the sunlit surface waters of the ocean. b) Biogenous oozes include sediments that contain at least 30% CaCO3 tests. c) Biogenous oozes are created by underwater eruptions, which cover the sea floor with fine ash particles. d) Biogenous oozes include sediments that contain at least 30% SiO2 tests. e) Biogenous oozes are composed of the hard remains of once-living organisms.
c) Biogenous oozes are created by underwater eruptions, which cover the sea floor with fine ash particles.
Most chalk is made from ___________. a) Oolites b) diatomaceous earth c) Coccoliths d) Radiolarians e) manganese nodules
c) Coccoliths
Which of the following statements about manganese nodules is FALSE? a) Manganese nodules are a type of hydrogenous sediment. b) Manganese nodules form in layers around a central nucleation object, such as a grain of sand or a shark's tooth. c) Manganese nodules are a type of foraminifera. d) Manganese nodules are thought to precipitate directly from seawater. e) Manganese nodules are composed of oxides of manganese, iron, cobalt, and other metals.
c) Manganese nodules are a type of foraminifera.
In sediments, what does the Wentworth scale describe? a) grain color b) grain density c) grain size d) grain shape e) grain composition
c) grain size
The two most common compouns that make up biogeneous sediment are _________ __________ and ________
calcium carbonate, silica
Sediments brought to the ocean by space dust and meteors (lithogeneous, biogeneous, hydrogeneous, cosmogeneous)
cosmogeneous
Sediments that contain iron-nickle spherules, iron-nickle meteorites, and silicate chondrites (lithogeneous, biogeneous, hydrogeneous, cosmogeneous)
cosmogeneous
Scientists can locate natural resources like _______ _________ and ________ ____ by studying sediments.
crude oil, natural gas
All of the following are examples of sediment-transporting media EXCEPT ___________. a) Streams b) Glaciers c) Gravity d) Wind e) Levitation
e) Levitation
Where are most modern-day calcareous oozes found in the ocean? a) in deep-ocean trenches b) near hydrothermal vents c) on abyssal plains d) along the mid-ocean ridge beneath warm surface waters e) anywhere beneath cold surface waters
d) along the mid-ocean ridge beneath warm surface waters
Beneath the calcite compensation depth (CCD), ___________. a) organisms with siliceous hard parts cannot live b) the water temperature rises c) abyssal clays cannot form d) calcium carbonate dissolves in seawater e) calcareous oozes are currently forming
d) calcium carbonate dissolves in seawater
The only way for siliceous ooze to be preserved in the ocean is ___________. a) during conditions of high salinity b) for the deposit to be mixed with hydrogenous sediment c) to accumulate above the CCD before it is transported to deeper depths by sea floor spreading d) to have it accumulate faster than it dissolves e) to have slow burial
d) to have it accumulate faster than it dissolves
Sediment maturity ___________ as sorting decreases. (increases,decreases)
decreases
Microscopic shells that create biogenous sediment on the sea floor are called ___________. a) Smush b) Slime c) Clays d) Nodules e) Tests
e) Tests
What lithogeneous neritic deposits are formed from turbidite currents and form graded bedding?
turbidite
_______ are made up of photosynthetic algae and are planktonic, they form light weight white rock. Found in cooler waters
diatoms
the deposition of other sediments decreases the percentage of biogeneous sediments. Determines the distribution of biogeneous sediment.
dilution
Sediments brought to the ocean by precipitating directly from sea water (lithogeneous, biogeneous, hydrogeneous, cosmogeneous)
hydrogeneous
Sediments that contain manganese nodules, phosphorite, oolites, metal sulfides, and evaporites (lithogeneous, biogeneous, hydrogeneous, cosmogeneous)
hydrogeneous
Which two sediments make up the smaller proportions of marine sediments? (lithogeneous, biogeneous, hydrogeneous, cosmogeneous)
hydrogeneous and cosmogeneous
rock particles trapped in glacial ice are carried out to sea by icebergs
ice rafting
Poorly sorted glacial deposits which contains large quantities of clay and poorly rounded grains are ___________. (mature,immature)
immature
Sediment maturity ___________ as clay content decreases. (increases, decreases)
increases
Sediment maturity ___________ as grains become more rounded (increases,decreases)
increases
Sediment maturity ___________ as you eliminate non-quartz material (increases,decreases)
increases
conversion of sediments to rocks by pressure or cementation
lithification
Sediments that were brought to the ocean by wind, rivers, volcanic eruptions, landslides, glaciers, gravity, and turbidity currents (lithogeneous, biogeneous, hydrogeneous, cosmogeneous)
lithogeneous
What is the most abundant sediment? (lithogeneous, biogeneous, hydrogeneous, cosmogeneous)
lithogeneous
What sediment is most abundant in neritic environments? (lithogeneous, biogeneous, hydrogeneous, cosmogeneous)
lithogeneous
_____________ sediment is deposited in bays, lagoons, deep sea ocean basin by turbidity currents (low energy), beaches, and the continental margin (high energy) (lithogeneous, biogeneous, hydrogeneous, cosmogeneous)
lithogeneous
What are the two main origins of the sediments found in the ocean? external _______ material and internal ________ + _________ material
lithogeneous, biogenic, hydrogenic
Well sorted beach sand that contains well rounded and very little clay is considered __________. (mature,immature)
mature
Glacial till and ice-rafted sediments dominate _______ shelves
polar
lithogeneous Continental shelf deposits are know as ________ sediments
relict
Spherules are made of silica and can contain space dust and ________ that are rare evidence of impact events.
tektites
river supplied sands and muds dominate _________ shelves
temperate
What controls the distribution of Sediments on the continental shelf?
tides, waves, and currents
Calcareous biogenic sediments dominate _________ shelves
tropical
Sediment composed primarily of particles the same size are _____ sorted
well
