name 4 states of dharwar system and vindhyan system ????
Answers
India, being a large country, has diverse geology. Different regions in India contain rocks of all types belonging to different geologic periods. Some of the rocks are badly deformed and transmuted while others are recently deposited alluvium that has yet to undergo diagenesis. Mineral deposits of great variety are found in the subcontinent in huge quantity. Structurally the Indian landmass is divided into three main divisions consisting of
The Himalayan Mountain Chain
The North Indian Plain; and
The Peninsular Plateau.
However, stratigraphically, India can be divided into several divisions such as Archean System, Dharwar System, Cudappah system, Vindhyan system, Paleozoic,Mesozoic, Gondwana, Deccan Trap, Tertiary and Alluvial.
Contents
Archean formations
Dharwar system
Cudappah System
Vindhyan System
Gondwana System or Carboniferous period System or Dravidian System
The Cretaceous system or the Deccan Trap
The Tertiary System
Archean formations
Archean rocks, also known as Pre-Cambrian rocks are the oldest rocks of the earth’s crust. The Archean period covers 86.7% of Total geological history time of earth and therefore is very significant. This period marks the development of first photosynthesis, the life support atmosphere.
The major characteristic of the Archean rocks is that they are azoid, means that are devoid of any form of remnants of life in them. They serve as the basement complex or fundamental gneisses.
The Archean rocks in India are called Purana Rocks means the oldest rocks. The Archean or Purana rock system in India is found in Aravallis mountains, 2/3rd of the Deccan peninsula and some parts of north east. These rocks have abundant metallic and non-metallic minerals such as iron, copper, manganese, bauxite, lead, zinc, gold, silver, tin, tungsten, mica, asbestos, graphite, etc.
Dharwar system
Dharwar system is later than the Archean system but older than the other systems. The Dharwar period of rock formation has been largely fixed from 2500 million years ago to 1800 million years ago. Dharwar Rock System is special because it is the first metamorphic sedimentary rocks in India.
They are named Dharwar system because they were first studied in Dharwar region of Karnataka. But they are also found in Aravallis, Tamil Nadu, Chotanagpur plateau, Meghalaya, Delhi, and the Himalayas region.
The Dharwar rocks are rich in iron ore, manganese, lead, zinc, gold, silver etc.
The Champions series containing gold mines lie within this system. This Champion system is named after the Champion reef in the Kolar Gold Fields. The Kolar Gold Fields contain one of the deepest gold mines of world.
The other series of Dharwar system are as follows:
Champaner series that is found near Baroda. This is source of a lush green variety of marble.
Closepet series that is found in Balaghat and Chhindwara of Madhya Pradesh. It is rich in Copper ores.
Chilpi Series that is found in and around the Closepet series in Balaghat and Chhindwara
Iron-Ore series that is located in Singhbhum, Mayurbnhanj and Keonjhar rangaes.
Cudappah System
Cudappah System rocks are rich in metamorphic rocks such as sandstone, shale, limestone, quartzite, and slate. They contain iron and other inferior quality of ores and minerals. They are mainly found in Cudappah district of Andhra Pradesh along with other places such as Chhattisgarh, Rajasthan, Delhi, and the lesser Himalayas. One of the important series of Cudappah System is Papaghani series, named after the river of same name in Andhra Pradesh.
Vindhyan System
The Vindhyan Mountains form a dividing line between the Ganges plain and Deccan Plateau. The Vindyan system is named after Vidhyan Mountains. This system rocks are extensively distributed in India from Chittorgarh (Rajasthan) to Sasaram (Bihar). The Vindhyan System is separated from Aravallis by the Great Boundary Fault. They are famous sources of Red Sandstone and other building material. The well known Panna and Golconda diamonds are found in this formation. The important series of this system are Bhander series, Bijwar series and Kaimur series. All are rich sources of Building material.
Gondwana System or Carboniferous period System or Dravidian System
As the name suggests, these are the major coal deposits of India. This system contains famous Damuda and Panchet series which are famous for coal deposits (discussed below). The important coal bearing areas of this series are Raniganj, Jharia, Karanpur, and Bokaro of the Damodar basin in Odisha, and the Pench valley in Chhattisgarh and Madhya Pradesh, the jhingurda coal seam (Chhattisgarh). The Gondwana Supergroup forms a unique sequence of fluviatile rocks deposited in Permo-Carboniferous time. Damodar and Sone river valley and Rajmahal hills in the eastern India is depository of the Gondwana rocks.