Mostly researched in U.S. Closely related to land Geology.
(a) Irregular floor - not a true gentle slope
(b) Deep and Irregular bays or fjords
(c) Deep troughs & shoals out to sea (troughs 100 FA +) basins are muddy
(some sand grainy)
(d) Fishing Baness (Cool & Warm H2O == food/ nutrients)
Banquerean/Nova Scotsa/ 50 fathoms
Grand Bank/ Newfoundland 100 fathoms
Floor from Boston Mass (East)
Mass Bay - Stelluragian Bank - Sand Ridge - Geoges Banks - (Possible Breakers) -
gradual shelf to 60 fathoms than shelf duplins greater
(2) Shelf With Elongated Sand Bank & Depressions
Usually smooth and sandy and flat (Cape Cod) New Jersey Note: At points
irregular of gravel beds
Shifty of Nantucket Shoals (Ship graveyard) (North Sea North of the English
channel/ Themes Estuary)
(3) Shelves with strong current actions
Straits of Florida (Narrow nick of the Gulf Stream (1 mile from shore only) Palm
Beach)
(a) Sand, gravel & worn shells
(b) Deep holes at Bay Mouth - golden entrance @ 64fathoms - Banrgo
Strait entrance to Tokyo Bay 230 fathoms. Poor Japanese defenses to
US subs during WWII
(4) Shelves Bordering Deltas
Mississippi River-Bird foot delta (23,36, & 50 Fathoms)
Indus Delta (50 fathoms)
Niger Delta - Bends Seaward
(a) Sediment is mostly muddy (high clay content if sand it is meca - more
easily transported
(b) Largest Rivers have mud than a sand border to seaward
Orinoco
Amazon
Yukon
South East Asia
Whang Ho
Sediment Size and Deposition Theory is Refuted
(5) Smooth Shelf- Sediment size diminishes seaward - thought to be the typical
type particles get finer and finer as you go further out to sea.
Arkansas Pass (Central Texas)
Sand
Mud
Shells - forams
Globigerina ooze
(6) Shelf with Salt Dome Shells:
Mississippi Delta - Gulf of Mexico
(1 mile diameter possible) trough or mountain surrounds - lime/coral on top
Dome stands above shelf
Economic Interest:
Texas and Louisiana Withdraw:
a. Sulfur
b. Salt
c. On periphery is oil
(Gravity potentials)
(Only other plan Dones and forest is on Persian Gulf)
(7) Shelves rimmed with Rocky Banks and Rocky Islands
a. Narrow shelf areas
b. Many caves
c. Great kelp
Tigreana River: from sand - boulders - cobbles - from sand - silt ~ coarse brown
sand (not usually gray)
(8) Shelf with Shallow Discontinuous Valley Systems
Shallow troughs - not deep
Sunda Shelf- (Brenda + Bonnes) (Jain /Indonesia)
Tidal appears to be reason but?
New York Harbor
Delaware & Chesapeake Bay
(9) Shelves Shoaled by Coral Reef
Australia Great Barrier Reef
(Not all coral are reef formers)