780 
recognition of all the features described 
above. Tne Sandy beaches show up as white 
strips, the tidal mudflats appear mixed 
areas of pink and blue and the lakes have 
recorded a deep blackksh blue shade. The 
marshes and the swamps are seen as blue are 
as. The basaltic cuestas show a paler shade 
of blue on the escarpments and a darker sha 
de of blue on the dipslopes. The ridge Cre 
stline of the Vikhroli-Ghatkopar range shows 
up as a fine line whereas the Kanheri range 
is seen as a very wide dark pink patch. The 
urban and suburban areea appear as very li 
ght areas with patches of pink representing 
vegetated hills. Open green turfs like the 
race course are seen as deep pink areas. 
The rocky beaches in the Juhu-Bandra stret 
ch show up as wavy blue lines along the sho 
reline. The salt fields are recognised by 
their white tone and the sandy spit at Ver- 
sova is clearly picked up as a fine, white 
projection into the sea. 
3 MAP DATA 
The topographical maps or. the scale of 1: 
63360 and the Town Guide Map on the scale 
of 1:25,000 wexe studied and these have 
added more local details while generally 
confirming the interpretation of the image 
ry. Rocky beaches can be clearly distingui 
shed from sandy beaches. The topographical 
contours not only give an idea about the 
relief dnd slopes but also indicate the 
attitude of the volcanic rocks through the 
landforms which are all structural landfor- 
ms. The tidal range is very clearly under 
stood from the maps and the drainage details 
over the mudflats are exceedingly clear. 
4 FIELD DATA 
Field traverses for the collection of grou 
nd truth have provided data on the rock ty 
pes and their attitudes. Three low ranges 
of volcanic rocks trending NNE-SSW traverse 
the island producing promontories bordered 
by cliffs. The volcanics, dominantly basalts, 
strike NNE-SSW and have westerly dips rang 
ing from 11° to 23°. Trachytes and rhyolites 
are exposed in the Madh island and north 
ward. Tuffs are found in the Kanheri range 
along with agglomerate. Intertrappean sedi 
mentarles are exposed at a number of loca 
lities like Jogeshwari. Dykes of dolerites 
are met with in Trombay and in the Powai 
hills o 
Geomorphological field investigations alo- 
^ the coast over the past ten years have 
revealed the recurrence of accentuated ma 
rine erosion in the area south of Versova. 
No other stretch along the coast has been 
or is undergoing erosion. Shetti and Subra- 
manyan (1985) have studied the spit which 
is trending southwestward from the mouth of 
the Malad creek and have attempted to simu 
late its growth through a computer progra 
mme. 
Field studies also indicate that the mul 
tistorey buildings have given rise to the 
densest concrete jungle in the Back Bay 
area in the southernmost part of the island 
and that urbanization is proceeding at a 
fast pace all along the coast in particular. 
Figure 2. Map showing the lineaments in the 
Bombay region and neighbourhood which appear 
to have controlled the creeks and the river. 
Figure 3. A geomorphic map 
of the Bombay region showing 
sandy beaches (1), rocky bea 
ches (2), marshes (3), tidal 
mudflats (4) and cuestas (5). 
5 DISCUS 
The coas 
Hite in 
shorelir 
bays an; 
marshy 1 
coast, i 
the pres 
concrete 
promontc 
NE-SW, r 
The re 
and the 
gence oi 
past. Th 
on the c 
believe; 
West Coe 
Volcanic 
Miocene 
coastlir 
This i 
of the \ 
ded by i 
which i£ 
ure desc 
flexure; 
the Konk 
shown or 
the Thar 
sion fre 
formed e 
southerr 
trending 
opened c 
region, 
led the 
island e 
area in 
the line 
triple ■ 
region e 
erosion. 
A reti 
had set 
ted the 
highly i 
* ria' ty 
med in 1 
and the 
urbanize 
sional £ 
and thej 
vity to 
is takir 
thmic re 
partly ; 
Madh prc 
ing the 
st whiclr 
former, 
the nori 
from ere 
from the 
Versova 
able to 
Versova 
up the t 
From thj 
point oi 
stretch 
require; 
by Shet-t 
It is 
ration c 
bays an; 
that the 
straight 
years.