88 
Records of the Geological Survey of India. 
[VOL. X. 
able thickness and a great variety of rocks, the principal of which are limestone, quartzites, 
hornstone-breccia, and slates. 
The lowest member of the group is a thick band of limestone called the Kushalgarh 
limestone. It is generally compact in texture, dark and light blue in color, the two shades 
arranged in alternate bands, and frequently contains an abundance of schorl, actinolite, and 
tremolite. The hornstone-breccia is generally found on the top of the Kushalgarh limestone, 
but is frequently absent. Above this there is a band of quartzite, upon which rests a con¬ 
siderable thickness of black slates frequently containing garnets and andalusite, capped by a 
quartzite, the Berla quartzite. 
So far the section of the Ajabgarh group is continuous in the valleys; but the upper 
rocks, being only exposed in the isolated ridges east of Alwar, are difficult to place in the 
section. The ridge extending from the Motidongri hill, close to Alwar, composed of alter¬ 
nations of calcareous and quartzite bands, is clearly higher in the section than the Berla 
quartzite ; and the Goleta ridge, about six miles east of Alwar, is probably still higher in the 
sectiou. 
The best sections of the lowest beds of this group are exposed in the Kushalgarh and 
Ajabgarh valleys. In the former, from the town of Kushalgarh to the mouth of the valley 
at Talbrich, the whole of the bottom of the valley, in places upwards of a mile wide, is 
occupied by the Kushalgarh limestone. Higher up the valley, rocks higher in the section 
come in. Both the breccia and quartzite are poorly represented, but the black slates are 
well developed and include thin and irregular bands of limestone as well as one or two bands 
of hornblende rock. 
A thicker section of the Ajabgarh group is exposed in the Ajabgarh valley. The 
Kushalgarh limestone resting upon the Alwar quartzites is seen on both sides, dipping 
towards the centre of the valley, though not so continuously on the west as on the east side. 
The hornstone-breccia and the quartzites above appear to be very irregularly developed in 
this valley. The breccia is nearly continuous on the west side, and there is but little of the 
quartzite, but on the east side, particularly at the northern end, a considerable thickness 
of the quartzites, but little of the breccia, is seen. The whole of the centre of the valley 
is occupied by the black slates. These rocks extend into the Narainpur valley as far as 
Gazeka Thana; but north of that there are only a few small hills of slates in the centre, 
and some of the limestone and breccia on either side of the valley. The remainder is 
covered by the alluvium. 
In the Delawas valley, patches of the Kushalgarh limestone are exposed on both sides 
of the valley ; the higher rocks occupying the centre are covered by the alluvium. Near 
Sillisur, about four miles south-west of Alwar, the hornstone-breccia above the limestone 
is exposed. It is in some places obscurely bedded, but it generally occurs in great masses 
devoid of any structure. It sometimes contains large pebbles of quartzite ; this is the case 
at the southern end of the Sillisur lake, where it is largely developed. 
The eastern edge of the Alwar quartzites at Alwar, and for a long way south, dips at 
an angle of about 80’ to the east under a broken section of the Ajabgarh group, here repre¬ 
sented by a few hillocks of the Kushalgarh limestone and breccia and the overlying 
quartzites. The slates are entirely covered by the alluvium which extends to the Moti¬ 
dongri ridge, formed of nearly the highest member of the group. 
Of the ridges to the east of the Motidongri ridge many are formed of the rocks of the 
Ajabgarh group. Thus, in the hills forming a broken circle a few miles east of Alwar, 
in the centre there is a hill oE the Alwar quartzites dipping in all directions towards the 
edge of the circle and under the encircling ridge of the Ajabgarh rocks consisting, on the 
