Oceanography Chapter 4

radiolarians

Have thin pseudopods that extend through hard shells made of silica(glass); many species are characterized based on shell morphology

sediments

Loose materials such as rock fragments, mineral grains, and bits of shell that have been moved by wind, water, ice, or gravity

upwelling

Movement of nutrient-rich bottom water to the ocean's surface. This can occur far from shore but usually occurs along certain steep coastal areas where the surface layer of ocean water is pushed away from shore and replaced by cold, nutrient-rich bottom water.

lysocline

The depth in the ocean in which the pressure is high enough and the amount of carbon dioxide in deep ocean water great enough to begin dissolving calcium carbonate.

aragonite

White, powdery variety of calcite

gravity corer

a hollow steel tube with heavy weight on top, was thrust into the sea floor to collect the first cores.

diatomaceous earth

a lightweight white rock composed of diatom tests and clay.

protozoans

any of diverse minute acellular or unicellular organisms usually nonphotosynthetic

turbidite deposits

are composed of characteristic layering called "graded bedding".

pelagic deposits

are found in the deep ocean basins and are typically fine grained.

neritic deposits

are found on continental shelves and in shallow water near islands; these deposits are generally coarse grained.

beach deposits

are made of whatever materials are locally available.

manganese nodules

are rounded, hard, golf to tennis ball sized lumps of metal that contain significant concentrations of manganese, iron, and smaller concentrations of copper, nickel, and cobalt, all of which have a variety of economic use.

microscopic spherules

are small globular masses. Can be composed of silicate rock material and show evidence of being formed by extraterrestrial impact events on earth or other planets that eject small molten pieces of crust into space.

carbonate minerals

are those that contain CO3 in their chemical formula.

turbidity currents

are underwater avalanches that periodically move down the continental slopes and carve submarine canyons.

continental shelf deposits

at the end of the last ice age glaciers melted and sea level rose. As a result many rivers of the world today deposit their sediment in drowned river mouths rather than carry it onto the continental shelf as they did during the geologic past.

red clay

because abyssal clays contain oxidized iron, they are commonly red/brown or buff in color and are sometimes referred to as red clays.

siliceous ooze

biogenous sediment composed of the silica based shells of single-celled animals and algae

siliceous ooze

biogenous sediment composed of the silica based shells of single-celled animals and algae (diatoms and radiolarins)

precipitate

change from the dissolved to the solid state.

texture

clues to sediment origin are found in its mineral composition.(size and shape of its particles)

Calcareous Ooze and the CCD

contains atleast 30% of the hard remains of the calcareous secreting organisms.

Neritic Deposits

cover about one quarter of the ocean floor

Pelagic Deposits

cover other three quarters. they are found on the relatively shallow deep ocean areas along the mid ocean ridge.

cores

cylinders of sediment and rock

meteorite

debris from meteors

Joides Resolution

glomar challenger was replaced by this in 1985, the new ship also has a tall metal drilling rig to conduct rotary drilling. The drill pipe is in individual section of 9.5 meters (31) feet and section scan be screwed together to make a single string to pipe up to 8200 long.

crusts

hard coatings on other rocks was more reliable source of cobalt.

ice rafting

in this process rock particles trapped in the glacial ice are carried out to sea by icebergs that break away from coastal glaciers.

Wentworth scale of grain size

indicates that particles can be classified as boulders (largest), cobbles, pebbles, granules, sand, silt, or clay (smallest).

Phosphorite

is a sedimentary rock consisting of various phosphate minerals containing the element phosphorus an important plant nutrient.

abyssal clay

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

hydrogenous sediment

is derived from dissolved material in water

Lithogeneous sediment

is derived from preexisting rock material that originates on the contents or islands from erosion, volcanic eruption, or blown dust. Is sometimes refereed to as terrigenous sediment.

Macroscopic biogenous sediment

is large enough to be seen without the aid of a microscope and includes shells, bones, and teeth of large organisms.

macroscopic meteor debris

is rare on earth but can be found associated with meteor impact sites. Evidence shows that throughout time meteors have collided with earth at great speeds and that some larger ones have released energy equivalent to the explosion of multiple large nuclear bombs.

stromatolites

layered rocks that form when certain prokaryotes bind thin films of sediment together

sorting

measure of the uniformity of grain sizes and indicates the selectivity of the transportation process.

test

microscope organisms produce tiny shells called ____________.

diatoms(cut in half)

microscopic unicellular marine or freshwater colonial alga having cell walls impregnated with silica

phosphates

mineral salts containing the element phosphorus

quartz

one of the most abundant, chemically stable, and durable minerals in the Earth's crust is called ___________. it is composed of silicon and oxygen in the form of SiO2, the same composition as ordinary glass.

grain size

one of the most important properties of lithogenous sediment is the texture, including its __________ _____________.

foraminifers

one source of calcium carbonate (foramen=an opening)

nannoplankton

plant-like protist; small spherical shell secretes tiny armored overlapping plates of the mineral calcium carbonate, mostly marine plankton forms; large accumulations produce rock chalk (UNICELLULAR)

algae

primitive chlorophyll-containing mainly aquatic eukaryotic organisms lacking true stems and roots and leaves

metal sulfides

rich deposits of copper, lead, zinc, and silver that are sometimes found along the margins of tectonic plates and originate during plate tectonics processes

Manganese Nodules

rounded hard lumps of manganese, iron, and other metals typically 5 centimeters in diameter. and can go up to 20 centimeters.

coccolithospores

second source of calcium carbonate (berry stone carrying).

limestones

sedimentary rock, composed of calcium carbonate. Soluble in water and weak acid.

evaporite minerals

solid homogeneous inorganic substances occurring in nature having a definite chemical composition

oolites

spherical grains formed by precipitation of concentric layers of calcium carbonate in a shallow-water marine environment where waves or currents periodically roll grains across the bottom

tektites

tekos=molten...then rain down on the earth and can form tektite fields.

planktonic

the aggregate of small plant and animal organisms that float or drift in great numbers in fresh or salt water

petroleum

the ancient remains of microscopic organisms, buried within marine sediments before they could decompose, are the source of today's_______________. Of the nonliving resources from the ocean, more than 95% of economic value is in _____________ products.

calcite compensation depth

the depth below whcih carbonate stops accumulatingcalcite is a variable soluble salt in sea water. colder water can dissolve a greater amount of carbonate.

ooze

these microscopic test can accumulate on the deep ocean floor and form deposits called ___________. fine grained mushy material.

rotary drilling

to collect core from the deep ocean. Today this is what we use.

pelagic deposits

turbidite deposits of neurotic sediment on the continental rise can spill over into the deep ocean basin.

Deep Sea Drilling Project DSDP

was initiated in 1968 when the specially designed drill ship Glomar Challenger was launched. It had a tall drilling rig resembling a steel tower. Cores could be collected by drilling into the ocean floor in water up to 6000 meters deep.

weathering

water, temperature extremes, and chemical effects break rocks into smaller pieces.

glacial deposits

were laid down during the most recent ice age by glaciers that covered the continental shelf and eventually melted.

Eroded

when rocks are in smaller pieces they can be more easily eroded (picked up) and transported.

salt deposits

when sea water evaporates, the salts increase in concentration until they an no longer remain dissolved, so they precipitate out of solution and form ___________ __________.

chalk

when the ooze lithifies over time, it forms a white deposit called _____________.

microscopic biogenous sediment

which contains particles so small they can be seen well only through microscope.

calcium carbonate

which forms the mineral calcite and silica. Often the silica is chemically combined with water to produce SiO2*nH2O the hydrated form of silica which is called opal.

Integrated Ocean Drilling Program

whose main participants are Japan, the US, and European Union, and uses multiple vessels. Also in 2003, the ODP was replaced by this.

Ocean Drilling Program ODP

with 20 participating countries under supervision of texas A&M University and a broader objective of drilling the thick sediment layers near the continental margins.