Download Marine Sediments - Rudy Marmolejo`s E

Presented by: Derek Lumary
Rudy Marmolejo
Jazmin Quijada

Marine Sediments are

They reveal much about
particles of organic or
Earth’s history, such as
inorganic origins that
providing clues to past
accumulate, and are found
geographic distributions of
within the ocean.
Marine Organisms,
movements of the ocean floor,
ocean circulation patterns,
climate changes on Earth, and
even global extinction events.


When sediments become

Clues to sediment origin
lithofied they form
are found in its mineral
sedimentary rock.
composition and its
Most rocks found on the
texture, which is the size
continents are
sedimentary rocks,
which are uplifted onto
land by the plate tectonic
process.
and the shape of its
particles.
Dredging

One way to collect Marine Sediments is through
dredging, which is a process that involves using a
bucket-like device to scoop up sediments.
Example: The techniques inefficient.
Rotary Drilling

The other common
method used is rotary
drilling, which uses a
hollow steel tube with a
heavy weight on top
that’s drilled into the sea
floors in order to collect
cores.
DEFINITION:
CHARACTERISTICS:

Lithos = Stone

Generare = To produce
rock material that

Sometimes referred to as
originates on the continents
Terrigenous Sediment.
or islands from erosion,

It derives from pre-existing
volcanic eruptions, or
blown dust.

They begin as rocks on continents or islands.

Over time weathering agents such as water,
temperature extremes and chemical effects brake
rocks into smaller pieces.

When rocks are in smaller pieces, they can be
picked and transported.

This eroded material is the basic component of
which all Lithogenous Sediment are composed.

This newly eroded material from the continents
is carried to the oceans by streams, wind,
glaciers, and gravity.

The greatest quantity of Lithogenous material is
found around margins of the continents, where it
is constantly moved by high-energy currents
along the shoreline and in deeper turbidity
currents.

The composition of Marine Sediments reflects
the material from which it was derived.

The majority of Lithogenous deposits such as
beach sands are composed primarily of quartz.

Quartz is a major component of most rocks, it is
resistant to abrasion, it can be transported long
distances and deposited far from its source area.
Neritic Deposits
 Found
on continental
Pelagic Deposits
 Found
in the deep
shelfs and in shallow
ocean basins and are
waters near islands.
typically fine-
grained.

Beach Deposits Made of whatever material is
locally available. They are composed mostly of
quartz and transported by waves that crash into the
shoreline.

Continental Shelf Deposits We relict (left behind)
sediments from 3k-7k years ago that hasn’t been
covered yet. These sediments presently cover about
70% of the world’s continental shelfs.

Turbidite Deposits These deposits are spread out as deep sea
fans due to turbidity currents. They are called Turbidite Deposits
and are composed of characteristic layering called graded
bedding.

Glacial Deposits Rock particles trapped in glacial ice are carried
out to sea by icebergs that break away from costal glaciers. As the
icebergs melt Lithogenous particles of many sizes are released
and settle onto the ocean floor, this process is called ice rafting.
 Abyssal
Clay Also referred to as red
clay due to oxidized iron. It’s composed
of at least 70 % fine clay sized particles
from the continents. It transports itself by
ocean winds and ends up deep down in
the ocean floor.
DEFINITION:

Bio = Life

Generare = to produce
CHARACTERISTICS:

It is derived from the
remains of hard parts of
once-living organisms.

The organisms that
contribute to biogenous
sediment are mainly algae
(seaweed) and protozoans
(primitive sea organisms).
 They
begin as the hard parts of living
organisms (i.e. shells, bones, and teeth)
ranging from small protozoan's to fish and
marine mammals.
 When
organisms such as these die, their
remains settle onto the ocean floor and can
become biogenous sediments.
1) MACROSCOPIC
BIOGENOUS SEDIMENT

Sediments that are large
2) MICROSCOPIC
BIOGENOUS SEDIMENT

small they can only be seen through a
enough to be seen without
the aid of a microscope,
Sediments that contains particles so
microscope.

They produce tiny shells called “tests”
that begin to sink after the organisms
such as shells, bones, and
die and continually rain down on the
teeth of large organisms.
the deep ocean floor and form deposits
ocean floor, which can accumulate on
called “ooze”.

Ooze is typically a fine-grained
lithogenous clay that is deposited in the
deep ocean.
DIATOM
RADIOLARIAN
[1] Silica Most of the silica in biogenous ooze comes from microscopic algae called
“diatoms” and protozoans called “radiolarians”.

Diatoms are mostly free-floating or planktons. When there is an abundance of diatoms
on the ocean surface, thick deposits of diatom-rich ooze can accumulate on the floor.

Radiolarians are microscopic single-celled protozoans, most of which are also
planktonic.

The accumulation of siliceous tests of diatoms, radiolarians, and other silica-secreting

[2] Calcium Carbonate The two sources of calcium
carbonate biogenous ooze are the foraminifers and
microscopic algae called coccolithophores.


{1} Foraminifers are singlecelled protozoans, many of
which are planktonic, ranging
in size from microscopic to
macroscopic. Ex: shells that can
be found at the beach.
{2} Coccolithophores (aka nannoplankton) are
single-celled algae, which are mainly
planktonic. When this organism dies, the
individual plates disaggregate and can
accumulate on the ocean floor as coccolithrich ooze. Eventually, as this ooze lithofies
over time, it forms a white deposit called
chalk, which is used for purposes such as
chalk sticks for writing on chalk boards.
Deposits comprised primarily of tests of foraminifers, coccoliths, and other
calcareous-secreting organisms are called calcareous ooze.
 COCCOLITHOPHORES
FORAMINIFERS
The White Cliffs of Southern England
The distribution of biogenous sediment on the ocean floor depends
on three fundamental processes.

[1] Productivity, which is the number of organisms present in the
surface water above the ocean floor.

[2] Destruction, which occurs when skeletal remains (tests)
dissolve in seawater at depth.

[3] Dilution, which occurs when the deposition of other sediments
decreases the percentage of the biogenous sediment found in
marine deposits.
Neritic Deposits

Although Neritic Deposits are
Pelagic Deposits

Microscopic biogenous sediment
mainly composed of lithogenous
(ooze) common on the deep
sediment, microscopic and
ocean floor because there is so
macroscopic biogenous material
little lithogenous sediment
can be found within lithogenous
deposited at great distances from
sediment in these deposits.
the continents that could dilute
the biogenous material.

Carbonate Deposits Rocks from the marine environment
composed primarily of calcium carbonate are called limestones.
Most limestones contain fossil marine shells, suggesting a
biogenous origin. Ancient marine carbonate deposits constitute
2% of Earth’s crust and 25% of all sedimentary rocks on Earth

Stromatolites Are roundish structures consisting of fine layers of
carbonate that form in specific warm, shallow-water environments
such as the high salinity tidal pools in Western Australia. As layer
upon layer of these algae colonize the surface, a bulbous structure
is formed.

Siliceous Ooze Siliceous Ooze contains
at least 30% of the hard remains of
silica-secreting organisms. One way to
accumulate siliceous ooze on the ocean
floor is to collect the siliceous tests
faster than seawater can dissolve them.
This process and ooze is commonly
found in areas below surface waters with
high biologic productivity of silicasecreting organisms.
*HOW IT ACCUMULATES*

Calcareous Ooze and the CCD Calcerous ooze contains at roughly about 30% of hard
remains of calcerous-secreting organisms. The destruction of calcium carbonate varies
with depth. The depth in the ocean at which the pressure is high enough and the amount of
carbon dioxide is great enough to begin dissolving calcium carbonate is called the
lysocline. Below this, calcium carbonate dissolves at an increasing rate with increasing
depth until the calcite compensation depth (CCD) is reached.

Currently there has been an increase in ocean acidity due to higher levels of atmospheric
carbon dioxide caused by human-caused emissions.

Aside from this, sea floor spreading causes the newly created sea floor and the calcerous
sediment on top of it to move into deeper water away from the ridge, eventually being
transported below the CCD.
SEA FLOOR SPREADING AND SEDIMENT ACCUMULATION
 Hydrogenous
Sediments are derived
from dissolved material in the water or
are formed by the interaction of
substances dissolved in water.
 Rounded
lumps of manganese, iron, and
other metals.
 When
cut in half they reveal a layered
structure around a central object.
 Occur
as coating on rocks and as
nodules. Typically found on the
continental shelf and on banks at depths
shallower than 1000 meters.
 Hydrogenous
carbonate deposits can
precipitate directly from sea water in
tropical climates.
 Metal
sulfides come from hydrothermal
vents and black smokers along the mid
ocean ridge.
 Deposits
of metal sulfides contain nickel,
iron, copper, zinc, and silver.
 These
deposits can be found throughout the
ocean floor due to sea floor spreading.
 Evaporites
minerals form where ever
there is a dry climate and restricted open
ocean circulation.
 Cosmogenous
comes from the root words
• Comso: universe
• Generare: to produce
o Sediments is derived from extraterrestrial source
Consists of two main types:

Microscopic spherules
 Macroscopic meteor debris

Microscopic spherules
• Small globular masses
• Composed of silicate rock material

Cosmogenous sediments are extraterrestrial in
nature and are generally like miniature meteorites.
These sediments are the remains of impacts of large
bodies of space material (such as comets and
asteroids). They are comprised of silicates and
mixtures of different metals.
 Other
spherules are composed from iron
and nickel which are formed in the asteroids
belt between the orbits of mars and Jupiter
and are produced when these asteroids
collide.
 These
tektites which are molten rain down
on earth and can form tektite fields.

When this material rains down on earth they form a general
component of space dust or micrometeorites that float harmlessly
throughout the atmosphere of earth.

About 90% of these micrometeorites are destroyed by frictional
heating as they enter the atmosphere.

Estimates show as much of 300,000 metric tons of space dust reach
earth surface each year, and about 22 pounds over second of
everyday.

The space dust that lands on the ocean is dissolved by the
seawater once it is touched.

Glassy tektites do not easily dissolve and sometimes
they comprise minute portions of various marine
sediments.

The debris from the meteors is called meteorite material
which settles around the impact site and is either composed
of silicate rock material which is called chondrites or iron
and nickel.

This happens when meteoroids collide on earth at a fast
speed and much larger meteoroids release energy
equivalent to the explosion of multiple nuclear bombs.

Comsogenous sediments are different from any
other types of sediments.

Cosmogenous particles from outer space
typically contain more nickel than those that
originate in other ways.

Most of the nickel in the earth crust sank below
the surface during density stratification early in
earths history.
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Petroleum
Sand & Gravel
Evaporative salts
Rare-earth Elements