Transcript Ocean-Floor Sediments (19.3)

Ocean-Floor Sediments
(19.3)
Sources of Deep Ocean-Basin
Sediments
• Refresher!!! What is a deep ocean-basin?
• Part of the ocean floor that is under deep
water beyond the continental margin.
• Sediments usually finer
• Collected using core samples
• Samples show slow settlement and can be
organic or inorganic
Core Samples
A scientist
studying a core
sample that was
collected by
drilling into
sediment layers
on the ocean
floor.
Inorganic Sediments
• Rocks carried from land by rivers
• Volcanic dust blown into ocean by wind
• Glaciers pick up sediment
deposit in ocean
iceberg
• Meteorites vaporize in atmosphere but
creates dust that enters Earth’s atmosphere
Inorganic sediment deposited by a
river in Indonesia
Biogenic Sediments
• Majority of sediments on ocean floor are
Biogenic
• Biogenic: sediments that are the remains
of marine plants and animals.
• Most common compounds found in
organic sediments are silica and calcium
carbonate
Chemical Deposits
• Chemical reactions in ocean produce solid
materials that eventually settle to ocean
floor as potato shaped lumps of minerals
called nodules.
• Nodules commonly located on abyssal
plains.
Nodules
Lumps of minerals
that are made of
oxides of
manganese, iron,
copper, or nickel that
is found in scattered
groups on the ocean
floor.
Physical classification of sediments
• Two basic types
• (1) Muds: fine silt and clay sized particles
of rocks. E.g. red clay
• (2) Ooze: soft, fine sediment. E.g. biogenic
materials
– Calcareous ooze-made of calcium carbonate
– Siliceous ooze-made of silicon dioxide.