126 
THE GEOLOGIST. 
tains on wliose flanks they had reposed. These icebergs would 
frequently become stranded on the neighbouring coasts^ and, 
yielding to the influence of temperature, would deposit their 
boulders on the bed of the ocean. By these means, most pro- 
bably, have the primitive rocks of Cumberland been transported 
to, and scattered over, the surface of Lancashire and Cheshire ; 
and to this cause we must assign the association of erratic boul- 
ders and marine remains in the same deposit .^^ 
GEOLOGICAL SOCIETY OF LONDON. 
Nov. \Qth. — Mr. Murchison, President, in the chair. Three 
papers were read, 
1st. On the Structure of the Delta of the Ganges, as exhi- 
bited by the Boring Operations in Fort William, a.d. 1836-40,'^ 
by Lieut. R. Baird Smith, Bengal Engineers. 
Since the year 1804, a number of boring operations have been 
conducted in the Gangetic Delta, with a view to supply the de- 
ficiency of good fresh water in the vicinity of Calcutta, but from 
mechanical obstacles, without success. The geological results of 
the last of these experiments, commenced in April 1836, and 
and which were abandoned in 1840, after being carried on to the 
depth of 480 feet, are detailed by Lieut. Baird Smith in this 
memoir. After penetrating to the depth of ten feet through the 
artificial surface soil, a bed of blue clay, close and adhesive in its 
texture was entered; as the bore descended, the clay became darker 
in colour, till in from 30 to 50 feet, large portions of peat with 
decaying fragments of trees were found. This peaty stratum had 
been formed from the debris of forests which formerly covered 
the entire surface of the Delta. Succeeding these peat charged 
beds, a stratum of calcareous clay, 10 feet in thickness, is found, 
and intermixed with it are portions of the concretionary lime- 
stone, commonly known in India as Kankur. Underlying the 
bed of calcareous clay in which the Kankm* first occurs, there is 
a thin bed of green silicious clay, extending from 60 to 65 feet 
