Jamalganj Fm
Period:
Neogene
Age Interval:
Early to Middle Miocene
Province:
Bangladesh NW
Type Locality and Naming
Lithology and Thickness
Alternating sandstone, siltstone and shale. About 415 m thick.
Lithology Pattern:
Clayey sandstone
Relationships and Distribution
Lower contact
Disconformable onto Bogra Fm of Oligocene
Upper contact
Overlain disconformably by the Dupitila Fm of Pliocene
Regional extent
Stable platform of NW Bangladesh. Equivalent formation in West Bengal is the Pandua Fm, which is more than 1500 m thick.
GeoJSON
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Fossils
Age
Age Span:
Beginning stage:
Aquitanian
Fraction up in beginning stage:
0.2
Beginning date (Ma):
22.52
Ending stage:
Tortonian
Fraction up in the ending stage:
1.0
Ending date (Ma):
7.25
Depositional setting
"Thought to have been deposited in a large delta complex."
Depositional pattern:
Additional Information
Compiler:
Extracts from Md. Shamsul Islam and Md. Jahangir Alam (2009, "Geological aspects of soil formation in Bangladesh", conference paper in ResearchGate); and from Md. Alam et al. (2003, "An overview of the sedimentary geology of the Bengal Basin in relation to the regional tectonic framework and basin-fill history", Sedimentary Geology, 155: 179-208.)