OCNG test 2 chapter 4

biogenous ooze must contain at least __% biogenous test material by weight

30

siliceous ooze contains at least __% of the hard remains of silica secreting organisims

30

calcerous ooze is preserved at depths wher water is ___

<4500m

__ __ is composed of at least 70% of fine, clay sized particles from the continents

abyssal clay

what are the four thing that contribute to the pelagic zone?

abyssal clay, volcanic ash, wind & deep ocean currents

__ are primarily aquatic, eukaryotic, photosynthetic organisms, ranging in size from microscopic single cells to large organisms like giant kelp

algae

what are the two organisms that chiefly contribute to the biogenous sediments?

algae & protozoans

80 % of world wide sediment discharge comes from __ rivers

asian

radiolaria eat __

bacteria

__ materials are made mostly of quartz-rich sand that is washed down to the coast by rivers but can also be composed of a wide variety of sizes & compositions

beach

what are the four examples of neritic lithogenous deposits

beach deposits, continental shelf, turbidite & glacial deposits

the majority of lithogenous deposits - __ __- are composed primarily of quartz

beach sands

why does the destruction of siliceous biogenous particlesby dissoliving in sea water occur simultaneoulst & slowly at the depths

because the ocean is undersaturated with silica at all depths

__ sediment is derived from the remains of hard parts of once living organisms

biogenous sediment

deposits comprised of test of foraminifers, coccoliths other calcareous-secreting organisms are called __ ooze

calcareous

__ __ is found on the shalloer areas on the ocean floor beneath warmer surface water

calcareous ooze

__ is the snow line in the ocean

calcite compensation depth (CCD)

what are the two most common chemical compounds found in biogenous sediment?

calcium carbonate & silica

what are two importatn carriers for chemical constituents?

carbon & pollutants

what are the two types of neritic deposits

carbonate deposits & stromatolites

when the coccolith ooze lithifies over time, it forms a white deposit called _, which is used for a variety of purposes. Form the white cliffs of dover

chalk

when __ sized particles- may of which are flat- are deposited, they tend to stick together by cohesive forces

clay

what are the four things that can be recorded from sedimentary rocks?

climate, sea level, precipitation, & vegetation changes

__ are single celled algae, most of which are planktonic. Produce thin plates or shields made of calcium carbonate, 20 or 30 of which overlap to produce a spherical test. Photosynthesize. Often called nannoplankton

coccolithophores

when the organisms dies, the indiidual plates (called __) disaggregate & can accumulate on the ocean floor as coccolith-rich ooze

coccoliths

__ produce th stromatolies by trapping fine sediments in mucous mats

cyanobacteria

microscopic biogenous sediment (ooze) is common on the _ __floor

deep ocean floor (pelagic deposits)

__ occurs most often because of the abundance of coarse-grained lihogenous material in neritic environments, so biogenous oozes are uncommon along continental margin

delution

the destruction of calcium carbonate varies with _

depth

a large percentage of lithogenous particles that fins their way into deep ocean sediments far from continents are transported by prevailing winds that remove small particles from the continent's subtropical __ __

desert regions

__ occurs when skeletal remains (tests) dissolve in sea water at depth

destruction

where __ are abundant at the ocean surface, thick deposits of diatom-rich oze can accumulate below on the ocean floord

diatom

when the diatom ooze lithifies, it becomes __ __, a light weight white rock composed of diatom tests & clay

diatomaceous earth

__ photosynthesize, need strong sunlight & are found only within the upper, sunlit surface waters of the ocean

diatoms

most of the silica in the biogenous ooze comes from microscopic alga called __ & protozoans called __

diatoms & radiolarians

__ occurs when the depositionof other sediments decreases the percentage of the biogenous sediment found in marine sediments

dilution

_ was a technique that was just limited to gathering samples from the surface of the ocean floor

dredge

during early exploration of the oceans, a bucket like device called a __ was used to scoop up sediment from the deep ocean floor for analysis

dredge

__ __ particles are deposited where the energy level is low & the current speed is at a minimal

fine grain

what comprises the other 70% of ooze?

fine grained lithogenous clay that is deposited along with biogenous tests in the deep ocean

_ are single celled protozoans. Planktonic, don't photosynthesize. Produce a hard calcium carbonate test in which the organism lives. Their tests resemble the large shells that one might find at the beach

foraminifers

what are the two signficant sources of calcium carbonate biogenous ooze?

foraminifers & coccolithophores

__ deposits are poorly sorted, ranging from boulders to clays & may be found in the high latitude portions of the continental shelf

glacier

what are the two things that the lithogenous sediment texture depend on?

grain size & sorting

the __ __ is a hollow steel tube with a heavy weight on top- was thrust into the sea floor to collect the first cores (cylinders of sediment and rock)

gravity corer

__ energy transporting media predominate close to shore

high

in __ __ rock particles trapped in glacial ice are carried out to sea by iceburgs that break away from coastal glaciers

ice rafting

how is ancietn calcareous ooze found at greater depths below the CCd?

if they were moved by sea floor spreading

lithogenouse sediment tendes to become finer with __ distances from shore

increasing

the gravity corer was limited by?

its depth penetration

what two organisms don't live a trace when they die?

jellyfish & bacteria

rocks from the marine environment composed primarily of calcium carbonate are called __

limestones

_ sediments begin as rocks on continents or islands

lithogenouse (terigenous sediment)

__ sediment is derived from preexisting rock material that originates on the continents or islands from erosion, volcanic eruptions or blown dust (land & volcanoes)

lithogenouse (terigenous sediment)

__ energy currents distribute finer components that sttle out onto the deep-ocean basins

lower

what are the four conditions that causes calcite to dissolve?

lower temp, high pressure, higher CO2, & low ph

the depth in the ocean at which the pressure is high enough & the amound of carbon dioxide in the deep-ocean waters is great enough to begin dissolving calcium carbonate is called the __

lysocline

__ biogenous sediment is large enough to be seen without the aid of a microscope & includes shells, bones, & teeth of large organisms

macroscopic

what can biogenous sediment be classified as?

macroscopic & microscopic

the greatest quantity of lithogenous material is found around the __ of the continents, where it is constantly moved by high energy currents along the shoreline & in the deeper turbidity currents

margin

much more abundant is __ biogenous sediment, which contains particles so small they can only be seen well through a microscope

microscopic

where are the thickest sediments found?

near the gulf of mex

__ deposits are found on the continental shelves & in the shallow waters near islands; deposits are usually coarse grained

neritic

__ is made up from near the shore to the edge of the continental shelf

neritic

lithogenous sediment dominates most __ deposits

neritic

marine sediementary deposits can be categorized as either _ or __

neritic or pelagic

these microscopic tests can accumulate on the deep ocean floor & form deposits called __, resembled very fine-grained, mushy material

ooze

abyssal clays contain __ __ & for this reason, they are commonly red brown or buff in color

oxidized iron

__ relies n the sea floor sediments to gain insight into these past changes

paleooceanography

the study of how the ocean, atmospere, & land have interacted to produce changes in ocean chemisty, circulation, biology, & climate is called _

paleooceanography

__ deposits are found in the deep ocean basins & are typically fine grained

pelagic

most __ deposits are composed of fine grained material that accumulates slowly on the deep ocean floor. Carried by deep sea currents

pelagic

the distribution of biogenous sediments are most common as __ deposits

pelagic

most diatoms are free floating or __

planktonic

an example of __ sorted sediment is that which is carried by a glacier & left behind when the glacier melts

poorly

__ is the number of organisms present in the surface of the water above the ocean floor

productivity

what are the three elements that the distribution of biogenous sediement on the ocean floor depends on?

productivity, destruction & dilution

__ are any of a large group of single-celled, eukaryotic, usually microscopic organisms that are generally not photosynthetic

protozoans

what are the two minerals after some weathering of lithogenous rock

quarts & feldspar

one of the most abundant, chemically stable, & durable minerals in the earth's crust is __, composed of silicon & oxygen

quartz

what is the remaining mineral in a highly weathered rock?

quartz

what are the three minerals in the source rock of lithogenous

quartz, feldspar & mafic

__are microscopic single-celled protozoans, most of which are also plantonic. Have long spikes or rays of silica protruding from their siliceous shell. Display well developed symmetry

radiolarians

__ __is the latest form of getting sediment from the deep ocean floor

rotary drilling

well sorted particles mean that they are particles of the __ size

same

how was the lithogenous neritic sediment deposited on the continental shelf

sea levels rose & glaciers melted

the accumulation of siliceous tests of diatoms, radiolarians & other silica- secreting organisms produces __ __

siliceous ooze

what are the two types of pelagic deposits

siliceous ooze & calcareous ooze & the ccd

__ is a measure of the uniformity of grain sizes & indicates that selectively of the transportation process

sorting

eroded material from the continents are carried out to the ocean by __,__,__ & __

streams, wind, glaciers, & gravity

__ are lobate structures consisting of fine layers of carbonate that form in specific warm, shallow-water environments such as the high salinity tidal pools in shark bay

stromatolites

deposits laid down where wave actions is __ may be composed of primarily of larger particles - cobblers & boulders

strong (high energy)

microscopic organisms produce tiny shells called __ that begin to sink after the organisms dies & continually rain down in great numbers onto the ocean floor

tests

one of the most important properties of lithogenous sediment is its __, includeing its grain size

texture

in _ deposits, the neritc material spreads out as deep sea fans, comprises the continental rise & gradually thins toward the abyssal plans

turbidite deposits

siliceous ooze tyically forms below cool surface water regions, including areas of __, where the deep-ocean water comes to the surface & supplies nutrients that stimulate high rates of biological productivity

upwelling

lithogenic sediments are transported to the ocean by ?

water or air

weathering agents such as __,__, & __ __ break rocks into smaller pieces (lithogenous)

water, temperature, & chemical effects

coastal sand dunes are an example of _ sorted sediment

well

the __ __ __ _ _ indicates that particles can be classified as boulders, cobbles, pebbles, granules, sand, silt, or clay

wentworth scale of grain size