oceanography chap 4.1 - 4.3

turbidite deposits

A sediment or rock formed from sediment deposited by turbidity currents characterized by both horizontally and vertically graded bedding.

Neritic sediments come from

Beach, continental shelf, turbidity currents, and glacier deposits

beach deposits

Beaches are made of whatever materials are locally available. Beach materials are composed mostly of quartz-rich sand that is washed down to the coast

Calcarous ooze

Biogenous sediment composed of test of calcareous-secreting organisms

in 2003

International Ocean Discovery Program: many vessels, many countries.

Diatomaceous earth unusual properties

It is lightweight, has an inert chemical composition, is resistant to high temperatures, and has excellent filtering properties.

stromatolites

Layered rock that results from the activities of prokaryotes that bind thin films of carbonate particles together.

glacier sediments

Poorly-sorted deposits containing particles ranging from boulders to clays may be found in the high-latitude portions of the continental shelf.

ice rafting

The movement of trapped sediment within or on top of ice by flotation.

paleoceanography

a branch of oceanography that relies on sea floor sediments to gain insight into these past changes.

marine sediments are

a historical record

abyssal clay is

a pelagic lithogenous deposit

siesta key

a primarily quartz beach

glacial deposits

a sedimentary deposit formed by a glacier and characterized by poor sorting

limestone

a sedimentary rock consisting mainly of calcium that was deposited by the remains of marine animals

organisms that contribute to biogenous sediment are chiefly

algae and protozoans

where is calcareous ooze found

along the mid Atlantic ridge, not the deep-ocean basin

calcerous tests dissolve

anywhere below the CDD

pelagic sediments come from

are found in the deep-ocean basins

continental shelf deposits

are sediments found on the continental shelf, a generally flat zone extending from the shore beneath the ocean surface to the shelf break.

siliceous ooze is found in areas

areas of upwelling

quartz is common in

beach sand

siliceous ooze

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

Ocean Drilling Program

ca me from DSDP, in 1983 the rebrand to have a broader objective of drilling the thick sediment layers near the continental margins.

CCD

calcite compensation depth

coccolithophores blooms

can be seen from outerspace as they impact the blue water color

siliceous ooze build up

can only happen when in areas of high productivity, lots of tests falling

cline

changing over a space

chalk

coclith-rich ooze that has lithified

use rotary drills on ship to

collect core samples

siliceous ooze must

contain at least 30% of the hard remains of silica-secreting organisms

silica organisms

diatoms and radiolarians

things to take way from JOIDES

diverse effort on exploring the ocean floor and how much can be learned from a hunk of sediment from the ocean floor

litho sediments are

either pelagic or nertic

lithogenous rock comes form

existing continental rock through erosion

pelagic sediment size typically is

fine-grained

calcite organisms

foraminifers and coccolithophores

energy of depositional environment

higher the energy the larger the particle

why might you find calcareous ooze below the CCD

if they get buried by other sediment they do not dissolve

Deep Sea Drilling Project

in 1966, data from sediment samples confirmed sea floor spreading

JOIDES ship

in 1985 got a new ship that could conduct rotary drilling

siliceous ooze is found

in cold, deep water

what can we learn from cores

infer past environmental conditions such as sea surface temperature, nutrient supply, abundance of marine life, atmospheric winds, ocean current patterns, volcanic eruptions, major extinction events, changes in Earth's climate, and the movement of tectonic plates

productivity

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

what is the underlying bedrock of Florida

limestone

Neritic biogenous deposits

limestone and stromatolites

sediments over time become

lithified

the four main types of marine sediments

lithogenous, biogenous, hydrogenous, and cosmogenous

two types of biogenous sediment

macroscopic and microscopic

tests

microscopic shells

all rocks are composed of

minerals

destruction

occurs when skeletal remains (tests) dissolve in seawater at depth.

dilution

occurs when the deposition of other sediments decreases the percentage of the biogenous sediment found in marine deposits.

3 fundamental processes of distribution of bigenous sediment on the sea floor

productivity, destruction, and dilution

lithogenous is mostly made of

quartz

higher concentrations of calcium dioxide have

raised where the CCD falls

biogenous sediment

remains of hard parts from once living organisms

lithos

rock

the greatest quantity of lithogenous material is found

round the margins of the continents, where it is constantly moved by high-energy currents along the shoreline and by turbidity currents in deeper water

transported lithogenous sediment is found

round the margins of the continents, where it is constantly moved by high-energy currents along the shoreline and by turbidity currents in deeper water

Wentworth scale of grain size (largest to smallest)

s boulders (largest), cobbles, pebbles, granules, sand, silt, or clay (smallest).

relict sediments

sediments that were left behind

macro biogenous sediment made of

shells, bones, and teeth

two types of micro biogenous sediment

silica and calcite

Pelagic biogenous deposits

siliceous ooze and calcareous ooze

wind transport can only carry

small fragments of lithogenous sediment

Lysocline

space where the calcite is dissolving

micro biogenous sediment made of

tests from ooze/ fine grained

In the 1970s

the JOIDES became international

grain size

the average size of grains in a material

what is the CCD

the depth before the calcite test dissolve

in 1963

the first US collaboration to collect marine core samples

sorting

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

for siliceous ooze to appear

the rate of supply of test must be greater than the rate of dissolve

smaller vs large rock

the smaller the rock, the faster and farther it goes

diatomaceous earth

thick deposits of diatom-rich ooze can accumulate below on the ocean floor. When this ooze lithifies

lithified

turn to sedimentary rock

lithogenous sediment in the ocean is

ubiquitous

calcareous ooze is found in

warm, shallow temperatures

Joides in 2023 - 2024

was able to reach the mantle for the first time

lithogenous transport methods

wind, stream, glaciers, and gravity