Tectonic Divisions of India

 



Indian plate is composed of the Indian subcontinent and the northern part of the Indian Ocean.

LIMITS: It is separated from the Arabian plate in the west by Carlsberg ridge and Owen fracture zone.

Himalayas and Arakan-yoma ranges mark the northern and eastern limits of Indian plate respectively (product of collision between indian plate and Eurasian plates along the subduction zone).

Subduction zone is known as Indus-Tsangpo suture zone that marks the northern boundary of the Himalayas.

 

(1)PHYISIOGRAPHIC FEATURES:

Indian subcontinent: Indian craton has remained largely stable since late pre Cambrian.

The youthful Himalayas and Arakan yoma are active tectonic belts that are still undergoing tectonic uplift and erosion.

Himalayas(Neogene Period) as a barrier to the monsoon winds that lead to a great amount of precipitation over the mountains.

Indian Subcontinent is divisible into three geomorphic units:

·        Peninsular India

·        Extra Peninsular India

·        Indo-Gangetic Plains

(1)Peninsula is a triangular landmass that is bonded by Indian Ocean in south, Bay of Bengal in east and Arabian Sea in west.

(2)Northern boundary of the subcontinent is dominated by the youthful and lofty(Tall)mountains of Alpine-Himalayan belt that form the extra peninsular India.

(3)Indo-Gangetic Plain that is situated between the extra peninsular and peninsular India is the youngest geomorphic unit of Indian subcontinent.

 

Climate: Except Thar desert, Indian sub continent falls under the  humid tropical climate.

Thar Desert : Arid region.

Facts:

·        Mount Everest(8848),Highest peak of the world.

·        Guru Shikhar(1723), Highest peak of Aravalli range.

 

 (1)Peninsular India: It comprises of ancient folded mountains, plateau mountains and coastal plains.

 AGE: Since Archean age

(!)Plateau Mountains:

Deccan plateau: The deccan plateau dominates the topographic features of a greater part of Maharashtra and adjoining regions.

·        Major part of the Indian peninsula; is a triangular shaped rocky region(Altitude: 100 to 1000m)

·        It is bounded by three mountain ranges(North: Satpura Range, East: Eastern ghats; West: Western ghats)

 

Malwa Range: Along the northern flank of Narmada valley.

Bhander and kaimur ranges: Along the Son valley

Vindhya Mountains: Central India.

·        It has a gentle northerly slope that is drained by tributaries of the ganga river(Son river).

·        The southern slopes of the range are steeper and drained by the tributaries of the Narmada river (Here drained by meaning the movement of rainwater from mountain to respective river).

(!!)Western Ghats:

Also known as Sahyadri; Along the western fringe of peninsular India.

Extension: From Tapti River in the north to Kanyakumari in the south.

The central line of the range constitutes the watershed for the three major river basins of south India.

·        Godavari, Krishna, Kaveri; flow direction: Western Ghats to Bay of Bengal.

 

Geological characters of northern and southern parts of western ghats are different

Northern Parts: Plateau Mountains

Southern parts: Nilgiri, Anamalai, Cardamom hills of south india.

Nilgiri hills are separated from the southern hills by a 30 to 40 km wide pass of lower altitudes that is referred to as Palghat gap.

 

(!!!)Eastern Ghats: It is made up of discontinuous range of low lying ranges.

Extension: From West Bengal in the north to Tamilnadu in the south.

Older than western ghats.

Eastern ghats represent the erosional remnants of the folded mountains.

 

Narmada river: Flows westward into Arabian Sea is bordered by the Vindhyan Ranges in the north and Satpura Ranges in the south.

Narmada and Son rivers together define a lineament of continental dimension, known as Narmada-Son lineament that has been active since Mesozoic era.

Narmada and Son river originates from Amarkantak in MP.

(2)Extra-Peninsular India:  The Extra Peninsular India is made up of The Himalayan Mountain ranges in the north and Arakan Yoma in the east.

Since Cenozoic Era

HIMALAYAS:

AGE: Neogene Period(Cenozoic Era)

Extension: From Nanga Parbat in Kashmir to Namcha Barua in Arunanchal Pradesh.

Northern limit of Himalaya is marked by a tectonic zone Known as Indus-Tsangpo suture zone(ITSZ) that extends along Indus river in Ladakh and Tsangpo River in Tibet.

Divisions of Himalayas:

·        Trans Himalayas

·        Tethyan Himalayas(fossils present)

·        Greater/Higher Himalayas(Altitude: 6000m)

·        Middle or Lesser Himalayas

·        Outer or Shiwalikes

Outer Himalayas that is also known as sub-Himalayas comprises the low lying foothills in south of lesser Himalayas.

Outer Himalaya is known as

·        Shivalik Range: Himachal Pradesh and Uttranchal

·        Churia hills: Nepal

 

 

Indo-Gangetic Plains: One of the Largest alluvial plains.

AGE: Filled with Quaternary(Cenozoic Era) sediments.

Extension: From the mouth of Indus River(Draining into Arabian Sea in the West) through the Northern plains of India to the great sunder ban delta system of the Bay of Bengal in east.

The Plains are divided into two major river basins:

·        Indus Basin (in the west)

·        Ganga Basin (in the east)

Bramhaputra river that enters the plains in the upper assam joins the ganga basins.


PEACE OUT

-Ichbinaasif

 

 

 

 

Comments