72 Records of the Geological Survey of India. [vol. xiii. 
But the above are not the only remarkable features connected with these 
sources. There are found generally, in the Konkan, large numbers of basaltic 
dykes, more or less vertical, and usually running in lines straight or nearly so. 
These ai'e of various breadths, uj) to 40 feet or even more, and they occur most 
fi’cquently near the sources or craters described above. Thus there are numbers 
of them about the Berveo between Kalian and Budlajioor, and they are especi¬ 
ally thick between Moorbar and Kinnowlee, and at the head of the Malsege bay, 
under Sindloo and Hurreechunder. Not only ar’O they found in the floor of the 
Konkan, but they are seen to cleave the highest eminences of the ghauts, and 
they extend for some miles in to the Deccan, showing that they were,'poured out and 
injected after the great mass of the trap was laid down. It is remarkable also, 
that though so broad and extended so far as I saw, they are rarely, if ever, con¬ 
nected with any disjdacement of the intersected beds, or anything like a fault. 
It is remarkable also that the basalt which in Bombay is spread out as a sheet 
over the highest of the trap and greenstone beds, also caps the elevations of 
the ghauts, as may be seen at Khardalla, Beema-Shunker, and other places, 
though whether these horizontal sheets were caused by the overflow of the dykes, 
or whether, as is more probable, their material overflowed the craters in the 
usual way after the trap period had ceased, I could not ascertain. It is, however, 
evident from the mechanical position of the basalt whether in dykes or sheets, as 
well as from its relation to the batrachian fossils, that it was thrown up after the 
trap ; and probably both dykes and sheets, though not simultaneo us, belong to 
the same geological period. 
The basalt dykes deserve close attention. They are generally vertical, and 
very rarely magnetic. Also they are almost always composed of small prisms, 
the axis being at right angles to the course and faces of the dyke. Also they 
are commonly fringed at each face, the fringe or ‘ selband’ being broken up by 
vertical planes, parallel to the face of the dyke. The dyke beneath the fort at 
Kalian is columnar. The basalt is usually homogeneous, though now and then 
its surfaces are pitted as though small deposits of minei’als had been washed out. 
There is no cohesion between the pi-isms, so that the dyke is often a mere trough, 
the matter being removed. Kear the 'Wanaghaut where a largo dyke cleaves 
the nearly precipitous face, the basalt is so far removed that the dyke is repre¬ 
sented by a hollow chasm, and forms a steep stair-case, up which is a path for 
foot passengers. 
Although there is no vertical displacement connected with these dykes, the 
heat of the basalt has hardened and rendered tough the contiguous trap. The 
effect of this is curious. In the plain near Moorbar the country is intersected by 
a net work of steep and narrow banks from 100 to 200 feet high, some¬ 
what resembling the junction of a number of lines of railway in embankment. 
The axis of each of these banks is a dyke, the toughness imparted by which 
has enabled the banks to resist erosion, while the place of the dyke is marked by 
a trough a few feet deep, out of which the basaltic prisms, being loose, have been 
removed. 
Looking back to the immediate causes of the very peculiar configuration of the 
