Coastline Of India
coastline of 7516.6 Km [6100 km of mainland coastline + coastline of 1197 Indian islands
result of faulting of the Gondwanaland during the Cretaceous period. {Continental Drift}
As such the coast of India does not offer many sites for good natural harbours. [Indented coastlines of Europe
provide good natural harbours whereas African and Indian coastlines are not indented].
Bay of Bengal and the Arabian Sea came into being during the Cretaceous or early Tertiary period after the
disintegration of Gondwanaland.
Coastlines of Emergence and Submergence
Exam_mastery 1
Coastline of emergence is formed either by an uplift of the land or by the lowering of the sea level. Coastline of
submergence is an exact opposite case.
Bars, spits, lagoons, salt marshes, beaches, sea cliffs and arches are the typical features of emergence. {Marine
Landforms}
The east coast of India, especially its south-eastern part (Tamil Nadu coast), appears to be a coast of emergence.
The west coast of India, on the other hand, is both emergent and submergent.
The northern portion of the coast is submerged as a result of faulting and the southern portion, that is the Kerala
coast, is an example of an emergent coast.
1. Coramandal coast (Tamil Nadu) ==> Coastline of emergence
2. Malabar coast (Kerala Coast) ==> Coastline of emergence
3. Konkan coast (Maharashtra and Goa Coast) ==> Coastline of submergence.
Exam_mastery 2
Islands Of India
Andaman and Nicobar Lakshadweep
Islands were formed due to collision between Indian Plate Islands are coral islands. These islands are a
and Burma Minor Plate [part of Eurasian Plate][Similar to part Reunion Hotspot volcanism.
formation of Himalayas].
Andaman and Nicobar Islands are southward extension
of Arakan Yoma range [Myanmar][Arakan Yoma in itself is
an extension of Purvanchal Hills].
composed of 265 big and small islands [203 Andaman islands + 25 small islands
62 Nicobar Islands]
extend from 6° 45′ N to 13° 45′ N and from 92° 10′ E to 94° 15′ E
for a distance of about 590 km
Port Blair, the capital of Andaman Nicobar Islands lies in Amendivi Islands are the northern most while
the South Andaman. the Minicoy island is the southernmost.
Great Nicobar is the largest. It is the southernmost island surrounded by fringing reefs
and is very close to Sumatra island of Indonesia. The Car The largest and the most advanced is the Minicoy
Nicobar is the northernmost. island
Saddle peak (737 m) in North Andaman is the highest Their topography is flat and relief features such as
peak. hills, streams, valleys, etc. are absent.
Exam_mastery 3
Andaman & Nicobar Quick Facts
Indian Rock System (Archean, Purana, Dravidian & Aryan Rock System)
Archean Rock System (Pre-Cambrian Rocks)
Period of Formation: These are considered the oldest rocks, formed about 4 billion years ago at the time of the cooling
and solidification of molten magma in the upper crust of the earth’s surface.
Features:
Azoic (unfossiliferous)
Crystalline (because of volcanic origin)
Foliated (consisting of thin sheets)
Extremely contorted and faulted
Often formed as plutonic intrusions (volcanic rocks found deep inside)
Archean group of rocks consists of two systems-
1. Achaean System: Granites and Gneisses,
2. Dharwar System: First Sedimentary Rocks
Gneiss: These cover two-thirds of peninsular India. Their mineral composition varies from granite to gabbro. They possess
foliated or banded structures.
Schists: These are mostly crystalline.
Location:
Himalayas
Central and southern parts of the Peninsula
Orissa, Meghalaya, Madhya Pradesh, Chhattisgarh, and Chotanagpur Plateau of Jharkhand
Bundelkhand
Exam_mastery 4
