Indian Geo; Location and Geological survey of India

Often described as a tropical country although a large part lies in sub-tropics.
- 8⁰4’ N, 37⁰ 6’ N latitudes and 68⁰7’ E, 97⁰ 25’ E longitudes.
Area: Russia > Canada > USA > China > Brazil > Australia > India.
Total area: 32, 87,263 km². (2.4% of the world)
Longest coastline state: Gujarat.
Active volcano: Barren Island. (Andaman and Nicobar Islands)
Northern most point: Indira col.
Southern most point: Indira point / Pygmalion point in Great Nicobar.
India is 5.5 hours ahead of the GMT / UTC. (82½⁰ E)
Geological survey of India divides geological formations of India into four groups:
- The Archean system
  - Gneiss and schist rocks. (3 billion + years old)
  - Dharwar rocks. (2- 3 billion years old)
  - Initial crustal strata; rich in metallic minerals like Fe, Mn and Au etc.
  - Oldest rock on earth crust.
  - Are all azoic or unfossiliferous. (devoid of any sediment and any form of life)
- The purana rock system.
  - Cuddapah series of rocks. (1 – 1.5 billion years old)
  - Vindhyan series of rocks. (0.5 – 1 billion years old)
  - Predominantly sedimentary; consists of sand stones and limestone’s etc.
  - South east Rajasthan to Bundelkhand to Bihar, south Chhattisgarh and Odisha.
- Dravidian system.
  - Rocks aged between 300 – 500 millions of years.
  - Thick deposits are at J & K, Himanchal Pradesh, and uttarakhand.
- Aryan system.
  - Rocks formations ranging from Upper Carboniferous to recent.
  - The godwana series of rocks are of sedimentary nature.
  - Include fossils of living organisms and they comprise of 98% of the coal reserves of the country.
  - Largely found in Damodar valley (Jharkhand), Mahanadi valley (Orissa) and Godaveri valley (south Madhya Pradesh, Maharashtra and Andra Pradesh).