The state of Maharashtra is bestowed by diverse lithology ranging in age from Archaean to Recent, some of which are associated with rich mineral deposits. Maharashtra hosts important and unique rocks from Indian geology, mostly belonging to the Dharwar craton, Central Indian Supracrustal Belt and Bastar cra- ton.

1. Mr. K. D. Petare
Civil Engineering Department
SRE’S Sanjivani College of Engineering,
Kopargaon 423603
Advanced Engineering Geology
with Rock Mechanics
401004 Elective-I

2.  Mostly follows stratigraphy of Peninsular India
 From bottom to top stratigraphy Unconformably
overlain by one another
Deccan Trap (Cretaceous – Eocene)
Infratrappeans (Cretaceous)
Gondwanas (Upper Carboniferous – Cretaceous)
Vindhyans (Late Pre Cambrian to Early Cambrian)
Kaladgis (Pre – Cambrian)
Dharwars (Pre – Cambrian)
Archaean
Eparchaean
Unconfirmity

4.  Lithology
 Either vesicular or amygdaloidal Compact
 Also found rhyolite, granophyres, nepheline syenite
 Structures
 Generally horizontal
 Dip 50 to 100
 Columnar jointing
 Found as dykes in part of Gujrat, Narmada Vally Konkan &
NW Maharashtra
 Gentla folding – Satpura Region
 Faulting – some place of M.P.

5.  Classification
 Into three group
Upper Trap (450m) West coast of India Flow with
Intertrappean beds &
beds of volcanic ash
Middle Trap (1200m) Central India Flow with Intertrappean
beds & no beds of
volcanic ash
Lower Trap (150m) M.P. Flow with Intertrappean
beds & rare beds of
volcanic ash

6.  Occurrence or Distribution
 Found in Maharashtra, Gujrat, M.P., Karnataka, A.P.
 Economic Minerals
 Gemstones, Bauxite, Quartz, Amethyst, Agate&
chalcedony
 Building Stone
 Besaltic Origin
 Dence, durable, hard, tough, wearing resistance & black in
colour
 As rode stone
 As aggregate in cement concrete
 Economic Importance
 Black cotton soil
 Good aquifer – vesicular & highly jointed lava flow

7.  Giant Phenocrysts Basalt
 Phenocrysts of Plagioclase
 Up to 1cm
 At places 5 to 10 cm
Phenocrysts of
Plagioclase
Ground mass

9.  Solid or Compact Basalt
 No empty cavities
 Flow Compact basalt
 Occurs as thick extensive Flow
 Tabular flow
 Top & bottom plain Surface
 Lateral extend large – up to 20 km
 Thickness varies - may up to 70 km

11.  Vesicular & Amygdaloidal Basalt
 Empty cavities
 Cavities filled
 Usually occur 1 km lateral
 Up to 10 m thickness
 Low than compact basalt
 Rock are unjointed

13.  Next point- Varities of Deccan Trap Basalt