part 2 .] Racket: Arvaii Series in North-Eastern Bajputana. 
85 
of a circle. In the Alwar territory, where more extensive and continuous sections are ex¬ 
posed than elsewhere within our area, the rocks are folded up and repeated many times; 
thus, a short distance north of the Banganga river the same beds are repeated at least a 
dozen times in a section sixty miles long. The rocks have undergone a considerable amount 
of metamorphism, some of the quartzites being compact and vitreous, the limestones highly 
crystallised and full of minerals, such as shorl, actiuolite, tremolite, &e., and the schists and 
slates highly mineralised, containing an abundance of crystals of andalusite, staurotide, 
garnets, &c. An arkose rock, or pseudo-gneiss, locally forming the base of the series, is often 
so highly metamorphosed as to render it difficult, in places where good junction-sections are 
not exposed, to tell it from the older gneiss upon which it rests. 
A great variety of rocks is included in the series, the principal of which are quartzites, 
dolomitic limestone, contemporaneous trap, hornstoue-breecia, schists and slates. 
These have been grouped in the following manner, in descending order :— 
Mandan—slates, schists, quartzites. 
Ajabgarh—slates, quartzites, hornstone-breccia, limestone. 
Alwar—quartzite, conglomerate, schists, limestone, bedded trap. 
The Alwar group has been sub-divided in descending order into— 
Alwar quartzites, including irregular bands of schists, conglomerate 
Alwar group. , 
and contemporaneous trap, 
Baialo limestone, 
„ quartzite. 
The lowest beds, the Raialo quaTtzite and limestone, are only seen near the southern 
extremity of the Alwar hills north of the Banganga river. In the three bays of Andhi, 
Bhangarh and Baswa, the quartzite, compact in texture, regularly bedded, and grey in color, 
rests upon the gneiss and dips under the limestone. 
The limestone is highly crystallised and dolomitic, and abounds in tremolite, shorl 
and actinolite; it is often pure white, but marbles of a great variety of color and also of 
texture can be obtained. There are large spreads of the limestone at Baialo and Baldeogarh 
aud at Kho; in other places, as west of Andhi and in the Baswa bay, the thickness is con¬ 
siderably less. No good sections of the junction between the Baialo quartzites and the 
gneiss are exposed, although the two are often seen within a few yards of each other; the 
actual junctions are all covered by the debris. 
Both the Baialo quartzite and limestone are locally overlapped by the next higher member 
of the group, the Alwar quartzite, which then rests directly on the gneiss. A few good 
sections of the junctions are exposed, which shew that the Arvaii series is quite unconform- 
able to the gneiss. The Alwar quartzite is the most prominent member of the whole series, 
both from the extent of ground it covers, and from the highest and largest groups of hills 
being formed of it; also from the principal forts in the neighbourhood, those of Byana, 
Alwar and Rimtumbour being built on it. 
The thickness of the Alwar quartzites varies considerably in different sections; thus, in 
the Byana hills an enormous thickness of them is exposed in an unbroken section upwards 
of five miles long in which the rocks have a steady dip to the north of about 20°; but 
about Nithahar the lower beds die out and the quartzites are reduced to a few hundred feet. 
In the Lalsot hills, where the rocks dip at a much higher angle, the quartzites are in 
force. In the Alwar hills, too, there is in places a great thickness, but they thin out to 
a few hundred feet in a southerly direction. 
The quartzites are mostly light grey in color, regularly bedded and compact in texture, 
although coarser beds are of frequent occurrence. They also include, especially in the 
