PART ].] 
Annual Report for 187?. 
9 
Pimjiih. —Mr. Wynne was fully occupied during last season in majiping tlic 
structural features of tlio tertiary basin between tlic Salt Range and the moun¬ 
tains to tbe north, and often spoken of as the Potwar, or the Rawalpindi plateau. 
It is, on the whole, a broad synclinal, with many subordinate axes of flexure. 
The change.s in composition of these tertiary deposits according to po.sition with 
reference to the mountain region and to the great river courses, combined with the 
great disturbance they have undergone, is a constant obstacle to the attempt to trace 
the zone.s of contemporaneous strata. To do thi.s with any certainty will bo a 
work of great labour which the Survey is not at present prepared to undertake; 
yet until this is done, it will bo impossible with any nicety to indicate the order 
of succession of the vertebrate fauna, which form.s the chief interest of tho.se 
formations. The more regular sections of the corresponding deposits in Sind 
may furnish this impoi-tant clue to the horizon.s in the Sub-Hinialayan region. 
A sketch of Mr. Wynne’s work, with an outline-map, is given in the Records 
for last August. 
Mr. Theobald has added largely to our collections of fossils from these rocks 
in the Potwar during the past season; but it is only in an approximate and 
often doubtful way that the specimens can be assigned to the different horizons : 
Mr. Theobald reports favourably of the a.ssistance he has received in this work 
from the apprentice Kishen Singh. A notice of these collections up to date is 
given by Mr. Lydekker in the current number of the Records. 
The post-tertiary deposits of this region offer a study of much interest. They 
are found resting upon tilted Siwalik strata at very high levels over the actual 
river courses, so that prodigious denudation must have taken place since they 
were laid down. There is much evidence to suggest that glacial action took a 
direct part in the accumulation of some of these deposits. 
Sind .—During the working season of 1876-77, Mr. Blanford and Mr. Fcddcn 
completed the mapping of Sind, west of the Indus. A considerable portion of the 
country had been examined in the two preceding sciisons, but in several districts 
the examination had only Ixjen partial and preliminary. In the course of the pa.st 
season Mr. Blanford re-examined the Khirthar range from its northern termina¬ 
tion west of Jacobabad to the neighbourhood of Sehwan ; he then re-mapped the 
cretaceous rocks in the Laki range south of Sehwan, and after completing the 
geological lines in the Habb valley, and marching we.stward along the coast as far 
as Sonmiani, returned to Calcutta at the commencement of March, to continue 
his work on the geological manual. 
Mr. Fedden, starting from Karachi, mapped the largo tract of country west of 
the Laki range, from the neighbourhood of Sehwan to the sea, an area of nearly 
6,000 square miles. The ground had been partially examined before, but the 
greater portion of the details were completed during the pa.st season. Large 
additions were also made to the fossil collections provionsly obtained. 
So much of the geology of Sind had been determined in the two previous 
seasons that no very impoiiaut additions could bo expected. Still several slight, 
but useful, improvements were effected. The exact relations of the bed of trap 
B 
