BASIN OCEAN FLOOR

ObjectivesAt the end of the lesson the students

are expected to:

• identify the major features of the Ocean Basin Floor and the Oceanic Ridge

• label the features of the Ocean Floor

• List and describe the three types of Seafloor Sediment

The OCEAN BASIN FLOOR lies between the continental margin and the oceanic ridge.

Ocean Basin Floor

o Deep-ocean trenches

o Abyssal plains o Seamounts

DEEP-OCEAN TRENCHES are long, relatively narrow creases in the seafloor that form the deepest parts of the ocean

volcanic island arc- arc shaped row of active volcanoes

Challenger Deep(Mariana Trench)

- the deepest known part of the world ocean

ABYSSAL PLAINS are deep, incredibly flat features. These regions are likely the most level places on Earth.

SEAMOUNTS are isolated volcanic peaks which may rise hundreds of meters above the surrounding topography.

Some are formed as a result of hot spots while others may form near oceanic ridges

Volcanic islands in the Atlantic1. Azores2. Ascension3. Tristan da Cunha4. St. Helena

GUYOTS or TABLEMOUNTS are submerged, flat-topped seamounts.

MID-OCEAN RIDGE

Oceanic ridge or Mid-Ocean ridgeIs topographically elevated feature that is found near the center of the most ocean basins.

It is characterized by extensive faulting and numerous volcanic structures that have developed on the newly formed crust.

Mid-Ocean Ridge

SEAFLOOR SEDIMENTS

TERRIGENOUS SEDIMENTSBIOGENOUS SEDIMENTSHYDROGENOUS SEDIMENTS

TERRIGENOUS SEDIMENTS

oconsist primarily of mineral grains that were weathered from continental rocks

oaccumulates slowly (5000-50,000yrs to deposit 1cm abyssal clay layer

ocolor may be red or brown

BIOGENOUS SEDIMENTS

Biological origin- primarily shells and skeletons of marine animals and algae.

Types of Biogenous sediments

oCalcareous oozes-remains of foraminifera and coccolithophores

-may form chalkoSiliceous oozes-remains of radiolarians and diatomsoPhosphate-rich materials-from bones, teeth and scales of fish

HYDROGENOUS SEDIMENTS

Consist of minerals that crystallize directly from seawater through various chemical reactions

maa

Thank You!!!!!!