The document summarizes key information about the Deccan Traps volcanic formation in India. It describes the Deccan Traps as the largest volcanic formation in the Indian subcontinent, located between latitudes 17-24 degrees and longitudes 73-74 degrees. The document further classifies the Deccan Traps into upper, middle, and lower divisions based on their thickness and characteristics. It notes that the Deccan Traps cover an area of 500,000 square kilometers and have an estimated volume of 512,000 cubic kilometers.
3. INTRODUCTION
Deccan traps have been defined as the greatest volcano
formation of indian subcontinent.
They located between (17-24,73-74E) and on of the volcanic
feature on the earth.
Their thickness decreases towards east and in shahdol
district at amarkantak they are only about 160m thick.
Deccan traps are largely made up of lavaflows of basic
composition.
4. Age:-
o The age of lava flow ranges from upper cretaceous to lower
Eocene.
o Deccan traps have been regarded as of paleocene age on
the basis of the following evidences.
• The Deccan trap overlies the bagh and lameta beds which
are of middle cretaceous age.
• In the saurashtra area of Gujarat,the “Nummulitic beds”of
lower Eocene age
5. Structure:-
• The Deccan traps flows are generally horizontal in attitude.
• But gentle dips of order of 10(degree)have also been
observed at some places.
• Lavas are believed to have intrupted subarially through
fissures in the earth crust.
Example:-
• In Narmada valley they run in the ENE-WSW direction.
• In Kokan their strike is N-S direction.
• In a cutch area of Gujarat these dyes trend in the NNE-SSW
direction.
6. Classification:-
Division Distribution Characters
Upper traps
(500m)
NW Peninsula Lava flows with ash
beds and
intertrappeans.
Middle traps
(1300m)
Central India and
Malwa region.
Lavaflows with ash
beds. Intertrappeans
are rare.
Lower traps
(160m)
M.P and eastern region. Lavaflows with many
intertrappeans.Ash
beds are rare.
7. Occurrences
• It cover an area of 500
thousand square km.
• It has volume of 512000 km
cube.
• They occupy major parts of
Gujarat,Maharashtra and some
parts of Andhra Pradesh.
• In Maharashtra they found
near the Matheran and Pune.
8. Rocks:-
The majority of Deccan trap flows are Basalt with uniform chemical
composition.
Other Rock
Other Rock:-
1. Rhyolite
2. Granophyre
3.Nepheline synite etc.
Have also found in cutch area of Gujarat.
Rhyolite Granophyre Nepheline synite
10. Economic important:-
1)Road Metal:-
The Deccan tarp basalt use in road metal because
they have high crushing strength and good binding.
2)Building Stones:
The light colored Basalts are used as building
stones in many part of India.
3)Black Soil:-
The most fertile black soil of Malwa and Maharashtra,
have been derived from Deccan trap.
11. 4)Aquifers:-
The vesicular and highly jointed lavaflows form good
aquifers which the ground water is obtained.
5)Bauxite Deposits:-
Bauxite deposits are formed due to prolonged
weathering of the Deccan traps.