FORMATION OF SPITS AND TOMBOLOS

A Spit is a long, narrow ridge of deposited materials that extends from the mainland into the sea. An example in Brunei is Muara Spit and Kuala Tutong Spit.
When the spit is connected the island to the mainland to form a feature is called the Tombolos.

Spits & Tombolos

The long shore drift transports materials along the coast. If there is a sudden change in the direction of the coast, the longshore drift continues to transport the materials in the original direction to the deep sea
As the longshore drift enters the deep water, the materials are deposited. Over time, these materials accumulate above the water to form a spit.
The spit continues to grow with the continuous deposition of materials.
The spit join a nearby island to the mainland to form a tombolo.

formation of Spits

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FORMATION OF OFFSHORE BAR

Off shore bar is a long narrow ridge of deposited materials sand can be found lying away from and parallel to a coast.

OFFSHORE BAR

When the waves approach a gently sloping coast , friction between the waves and the sea bed causes the waves to break at some distance from the coast.
Over time, more materials  are built up parallel to the coast to form ridge of sand called offshore bar.
A body of coastal water may be partially or completely cut off from the open sea by the offshore bar. The body of water is called a lagoon.

FORMATION OF BEACHES

Beach is a zone of materials accumulated along the coast.

DID YOU NOTICE THE HEADLAND ROCKS ARE THE SAME COLOUR WITH THE BEACH DEPOSITED MATERIALS? EXPLAIN HOW THE PROCESS WORKS?

A beach is formed when deposited materials carried by waves are accumulated in a zone along the coast. The materials on the beach vary in size from fine sand to pebbles . The waves sort these materials according to the weight. The finer sand deposited nearer the sea and the coarser materials further inland.

The formation of caves, arches and stacks

Wave erosion along a line of weakness on the headland to form a notch
The notch is further eroded to form a cave
The cave is continually eroded until a hole is cut through the headland and an arch is formed.
Further erosion of the arch causes it to collapse , leaving behind the stack which is a left standing in the sea.

the features of Cave, Arches and Stacks

FORMATION OF CLIFFS & WAVE-CUT PLATFORMS

1. Wave erosion along a line of weakness produces a cut called a notch on the coast.
2. The notch is further eroded to form a cave, a hallow with an opening in  a mass of rock.
3. Further erosion causes the overhanging part of the cave to collapse into the sea and a cliff is left behind.
4. Continuous erosion causes the cliff to move back or retreat inland. Over time, a wave-cut platform is formed at the foot of  the cliff.

CLIFF & WAVE CUT PLATFORM FORMATION

CLIFF & WAVE CUT PLATFORM PICTURES

FOR ANIMATION DIAGRAM, GO TO http://www.bbc.co.uk/schools/riversandcoasts/coasts/change_coast/pg_07_flash.shtml