THE FORTH DISTRICT. 
41^ 
-i^ontal nor parallel. The sand under the gravel cover ex- 
hibits the counterpart of those peculiar wavy horizontal 
lines remarked in corresponding situations in the Edinburgh 
pits. A mile farther, on the banks of the Teath, and 20 
to 30 feet above its surface, the sand occurs similarly ar- 
ranged. Here the river flows rapidly over red sandstone. 
Sp. si. a little east of Ashmiil, at Merlin's Ford, in 
Blair-Drummond policy, a bank of fine micaceous sand 
skirts the valley. The small-gravel cover under the vege- 
table mould is of several feet. It passes in sundry places 
into the subjacent sand betwixt two traversing veins, the 
section presenting the trumpet-form, mouth upwards. Mi- 
nute shifts are common, at traversing veins. The general 
form is JcnoUed. It reposes on red till, and the traversing 
hollows are spongy. The common dip is SW., being con- 
trary to the surface in that direction, which rises into con- 
siderable swells of red till, reposing on red sandstone. 
Twenty feet lower, is an oblong level field of 100 acres, 
with a slight declination to S W. On the N. is a steep scarp, 
20 to 30 feet, the substratum gravel, composed chiefly of 
spheroidal sandstone, sometimes united by a black or pitchy 
base. This substratum transmits much water in spring. 
At the upper extremity of this field, the gravel terminates 
betwixt two ridges of old red sandstone, covered with red 
till, clayey earth, sand, and small gravel. Its opposite ex- 
tremity passes under the carse-clay. The river Teath here 
forms the north boundary of a tongue of higher land, ter-. 
minating at Blair-Drummond ; the southern bank, stretch- 
ing westward on the margin of the carse-clay, is composed 
of till, high and precipitous, surmounted with small-grained 
micaceous sand, many yards in depth, passing on the north 
into siliceous sand and gravel, exhibiting the common forms 
of arrangement. (This bank thus forms the counterpart 
of the one which passes by ^leriin's Ford). Three or four 
VOL v. E © 
