Records of the Geological Survey of India, 
[vol. n. 
56 
much the appearance of a syenite in similar condition. Pine muddy-looking or ashy trap, 
weathering to an olive-green minutely divided detritus, is another variety. Some of the 
dykes, &c., are of fine-grained purple colored trap, with white steatitic specks, a soft earthy 
or lava-like texture, are much less dense than the varieties abovement-ioned, and are some¬ 
times salt to the taste. 
With regard to the manner in which all those intrusive traps occur, nothing could well be 
more varied: dykes are particularly numerous in some localities; they also occur in 
faults, while local intrusions form hills projecting from the plains and Jurassic broken ground, 
like knots in decaying wood. In such cases, their outlines are either conical or combinations of 
this with steeply scarped forms. Some intrusions range through the country for many miles, 
presenting the most irregular lines both in plan and elevation, cutting across the aqueous 
strata, including large masses, intruded between them or forming hills either capped or under¬ 
laid by the Jurassic beds, or both one and the other, these being altered by the contact into 
various kinds of porcelainous or quat'tzitic rook, while one case occurs where a whole stream 
section of the aqueous rocks seems to pass by gradual intensity of alteration into solid trap 
in which planes resembling the original bedding can be traced for some distance as if the 
strata had been melted in situ, no marked difference of texture however existing in the trap, 
although the stratified rocks consist of alternations of calcareous sandy and thin shaly 
hands.* 
Other instances occur in which sandstone seems to have been completely melted and 
taken up by these traps; the matrix having yielded first and the quartz fragments and grains 
gradually becoming more separated and disappearing until they are quite lost at a very short 
"distance in the dark trap. This can be seen in hand specimens. 
Generally speaking, these large intrusions have an intricacy of arrangement forming a 
tangle which defies all effort at accurate representation upon a map of small scale, and some¬ 
times their basaltic trap is so magnetic as to deprive compass bearings taken from these 
points of any value, the variation being of inconstant amount. 
SDSB-TEBEIARY GBOTl’-t 
As already stated, the Jurassics or Dogger bods of Kutch, consisting of a calcareous or 
sandy and shaly marine series below, passes upwards into alternations of more ferruginous 
and more purely argillaceous and arenaceous beds,—in which land fossils (Zamiffi, Ferns, &c.) 
are cither rare or locally numerous,—these forming what are at present considered an 
upper member of the same group. At some period subsequent to the Jurassic, not clearly 
marked, but arguing from local as well as distant sources of information (in the Deccan and 
at Bombay), probably an early Tertiary one, the volcanic activity which produced the Bedded 
Trails came into operation. Observations here only show that traps were extensively in¬ 
truded through the Jurassic rocks, and that other traps, very probably connected with these 
as centres of eruption, constitute a thick series resting with marked unconformity upon these 
Jurassic strata. 
But overlying the Bedded Traps and, where these are absent, the rocks upon which they 
rest, is a marked hand of most peculiar aspect, having, in contact with these traps, a very 
volcanic appearance, but one entirely different from theirs. Its predominant colors are deep 
red and pure white, but it is finely varied with purple, orange, greenish, brown and black 
or blue tints, even brighter and more strongly contrasted than those ol' the Jurassic beds. 
Its lowest stratum in junction with the uppermost of the trappean flows is a curiously 
mixed and mottled one, brecciated, concretionary on a large scale, in places containing 
small white quartz grains, but generally consisting of a pure chalk-white or variegated 
purple and. lavender, unctuous, argillaceous, rock occasionally saline and speckled with white 
kaolin patches, giving it the appearance of an amygdaloid, sometimes to such a degree that 
it becomes undistinguishable from the purple trap found in several dykes among the Jurassic 
rocks. 
* This passage as it were ot' stratified into intrusive amorphous rook is so very peculiar that it may perhaps 
be deceptive. A place where the alteration of the beds ccasetl laterally and the trap might be said to commence was 
sought tor in vain, and the lines which may be, or at least simulate, original stratification apparently continuous with 
thole of the unaltered bedded roek cea6e to be traceable beyond a few yards into the trap. 
T The name Sub-Tertiary used here is only provisional. An examination of the fossils will probably cause it to 
be altered for another. It merely means that the beds arc below the highly fossilifcrons Nummiuitie and other 
Tertiary beds though above the Bedded Traps the Intertrappean beds of which are believed to be of Lower 
Tertiary Age. 
