The notes is given in very detail and understandable manner

1. Marginal marine depositional environment:-
 Deltas.
 Beaches.
 Barrier Island systems.
 Estuaries.
Deltas:-
Deltas form when velocity drops as the river enters a standing body of
water, typically this is at the coast as the river flows into the sea.
Flocculation:-
The process by which individual particles of clay aggregate into
small lumps. Flocculation occurs as a result of a chemical reaction
b/w clay particles and another substance, usually salt water.
Composition of Deltas:-
Deltas are usually composed of three types of deposit…….
Topset beds: The larger and heavier particles are the first to be
deposited , as the river losses energy.

2. Foreset beds: Particles travel a little further before they are
deposited as more steep angled wedges of sediment.
Bottomset Beds: The very finest particles travel the furthest
before very low velocity, leads to their
deposition.
Types of Delta:-
Deltas can be categorise into three main shapes
 Arcuate
 Birds Foot
 Cuspate
Arcuate delta:
The most common shape of Delta.
Characteristics :- Curving shoreline, distinct pattern of drainage and
typically more gravely deposits.
Ex:- The Nile Delta.
Birds Foot Delta:

3. Fingers of deposition build out into the sea along the distributaries
channels giving an appearance like a birds claw. Ex:- Mississipi delta.
Cuspate Delta:
It is shaped like a tooth by gentle but regular opposing currents in the
water body.
Beaches:-
Landforms and terminology in coastal regions:
 The foreshore.
 The backshore.
 The berm.
Foreshore:
The area most influenced by the high and low water marks and
breaking waves.
Backshore:
Submerged only during the highest tides and severest storms.
Berm:
The high point on the beach; the backshore –foreshore boundary. It
changes seasonally.

4. Summertime beach condition:-
Wintertime beach conditions:-

5. Movement of sand on the beach:-
 Movement parallel to shoreline.
 Caused by wave refraction.
 Huge volumes of sand are moved within the surf zone.
 The beach resembles a river of sand.
Beaches and Shoreline Processes:
 Erosion
 Deposition
 Human Development

6. Longshore current and longshore drift:
 Longshore current= zigzag movement of water in the surf zone.
 Longshore drift= movement of sediment caused by longshore
current.
Features of erosional shores:
 Sea arch Headland
 Sea stack Wave-cut cliff
 Marine terrace Sea cave
Headland

7. Wave cut Cliff
Sea Cave:

8. Barrier Island Systems:
 Common along Passive Margins.
 Sand is most common material.
 Gravel common in glacial terranes.
 Width is <100 to kms.

9. Long-shore current: moves down beach as a result of waves coming
into beach at an angle.
Barrier Environments:
 Beach
 Dynamic part of barrier.
 Sediment moves in and out of beach with storms.
 Barrier Interior
 Frontal dune ridge, secondary dunes
Estuaries:
Relatively small, partly enclosed coastal embayments are loosely called
coastal bays. Two broad types of coastal bays are recognized:
ESTUARIES and LAGOONS.
Definition:
Estuary as "the seaward portion of a drowned valley system which
receives sediment from both fluvial and marine sources.

10. Contains facies influenced by tide, wave and fluvial processes.
Physiographic, Hydrologic, and Sediment Characteristics of
Estuaries:
Seven basic types of modem estuaries are recognized.
1. Fjords: are high-relief estuaries with a U-shaped valley
profile formed by drowning of glacially eroded valleys
during Holocene sea-level rise.
2. Coastal-plain estuaries: are low-relief estuaries, funnel-
shaped in plan view, that are open to the sea.
3. Low-relief estuaries: that are L-shaped in plan view and that
have lower courses parallel to the coast are bar-built
estuaries.
4. Deltaic estuaries: occur on delta fronts as ephemeral
distributaries. Flask-shaped, high-relief rias backed by a low-
relief plain created by tectonic activ,ity are called compound

11. estuaries or tectonic estuaries
Wave-Dominated Estuary:
 ln wave-dominated estuary, tidal influence is small, and the mouth
of the estuary experiences high wave energy.
 Sediments tend to move alongshore and onshore into the mouth of
the estuary.
 This barrier prevents most of the wave energy from entering the
estuary; thus, only internally generated waves are present behind
the barrier.

12.  Depending upon tidal range and current velocity, a small number
of inlets may be kept open in this barrier.
Tide-Dominated Eshwries:
 Tide-dominated estuaries occur mainly on macrotidal coasts
where tidal-current energy exceeds wave energy at the mouth of
the estuary.
 Elongate sand bars develop parallel to the length of the estuary
from sand carried into the estuary from marine sources. These
bars tend to dissipate tidal energy.

13. Examples of tide-dominated estuaries include Cook Inlet, Alaska; Ord
River, Australia; Gironde Estuary, France; and the Severn River, United
Kingdom.
LAGOONAL SYSTEMS:
 Def: A coastal lagoon is defined as a shallow stretch of
seawater--such as a sound, channel, bay, or saltwater lake.
 Most modern lagoons are formed behind spits.
 Lagoons commonly extend parallel to the coast, in contrast
to estuaries, which are oriented approximately perpendicular
to the coast.
 Lagoons have no significant freshwater runoff.