From Nazla Bushra and Dr. Seraj

3. •Morphology
•Hydrology
•Quaternary Deposits
•Deltaic Lands & Wetland
Environment

4. THE INTERLINKED PROCESSES
Deltaic Lands
& Wetland
Environment
Morphology
Hydrology
Quaternary
Deposits

6. Indian
Landmass
Srilanka
71 million years ago
55 million years ago
38 million years ago
10 million years ago

8. Ganges-Brahmaputra Delta have 1670 million tons of sediment load per year.

11. Shillong Shield
Indoburman
Range
Bay of Bengal

13.  Stable Platform
 Deep (geosynclinal) Basin
Hinge
Zone

14. Dinajpur Shield
Bogra Shelf
Foredeep
Foldbelt
STABLE PLATFORM
HINGE ZONE
GEOSYNCLINAL BASIN
On the basis of thickness of sedimentary cover-
• Rangpur Saddle or Dinajpur Shield
• Bogra Shelf
• A narrow northeast-southwest
trending zone separated the two
units diagonally almost through
the middle of the country.
• Fold belt – in the east
• Foredeep – in the west

15. A
B

16. A. STABLE PLATFORM
1. Rangpur Saddle or Dinajpur Shield
2. Bogra Shelf
• Rajshahi-Bogra-Rangpur-Dinajpur areas
• Limited to moderate thickness of sedimentary rock
• Geologically stable & has not been affected by fold movement
• Sedimentary rocks of Paleeozoic, Mesozoic and Cenozoic Era
• In the north
• Thin to limited (130m to 1000m) sedimentary cover
• Moderate sediment cover (1 to 6 km).
• Sedimentary layers dips very gently towards southeast until it reaches the hinge zone.

17. A. DEEP (geosynclinal BASIN)
1. The Fold Belt
2. Bogra Shelf
• Lies to the south and east of Stable Platform.
• Greater Dhaka-Faridpur-Noakhali-Sylhet-Comilla-Chittagong Hill tract
areas and the Bay of Bengal.
• Huge thickness of sedimentary rock (maximum of 22 km near the
basin center).
• Huge thickness is a result of tectonic mobility causing rapid
subsidence and sedimentation.
• Sedimentary rocks (mostly sandstone & shale)of Tertiary age.
• Mild or no folding.
• Sedimentary layers horizontal to sub-horizontals.
• Free from major tectonic deformation
• Central part of the basin.
• Represented by river to delta plain topography at the surface.
• Folding of sedimentary layers into a series of anticlines & synclines
• Seen in the topography of the Chittagong-Comilla-Sylhet regions.
• Intensity of folding is greater towards the east than the western part.

19. • The Quaternary is
represented by
Pleistocene reddish
brown clay .
• A pebbly sand to occasional
gravelly deposit of river origin
below the alluvial is referred to as
Dihing Formation.
• Overlain by Bengal
alluvial of the Holocene
(Recent) fluvial plain
deposits at the top.

20. • The Quaternary rocks are
represented by Modhupur Clay
formation of Pleistocene age.
• Composed of
reddish to brownish
clay with
subordinate silt.
• Above is covered with about 1000 m
of sandy, silty & clayey sediment of
Bengal Alluvium of Recent (Holocene)
age.

21. • Bangladesh lies in the northeastern corner of the Indian subcontinent at the
head of the Bay of Bengal.
• It occupies major part of the Ganges-Brahmaputra delta - largest of its kind in
the world in terms of sediment load carried to the sea (Orton and Reading 1993).
• As the mega delta pro-graded south accompanied by rapid subsidence of the
basin, a huge thickness of deltaic to fluvio-deltaic sediments was deposited.
• The delta building is still continuing into the present Bay of Bengal and the broad
fluvial front of Ganges-Brahmaputra-Meghna river system gradually follows it from
behind.

22. • Imam, Bodrul (June, 2005), Energy Resources of Bangladesh,
Dhaka: University Grants Commission of Bangladesh
• Center for Environmental and Geographic Information
Services (CEGIS), House 6, Road 23/C, Gulshan-1, Dhaka-1212,
Bangladesh, Received 15 January 2005; revised 7 July 2005;
accepted 29 March 2006. Available online 14 September 2006.
• http:www. Geodeticsurvey. Org

23. THANK
YOU