File:The Quarterly journal of the Geological Society of London (12895160303).jpg

1864..
YOUNG GLACIERS.
45^
thick Boulder-clay. About a quarter of a mile below the house, the
detritus again crosses the stream, and throughout the rest of its
course, until it joins Megget, covers both banks, shrinking very much,
however, at the base of Dead- for-Cauld, whose coomb-like crags
form a recess in which lies a thick mass of Boulder-clay. Here the
moraine-matter contains an unusual number of scratched stones,
derived doubtless from the older glacier deposit. Craigdilly, the
hill on the east side of this, the lowest portion of Winterhope, presents
towards the burn a bare rocky slope, along whose base the detritus
is limited by a very distinct line, and by a series of moutonnee
surfaces indicating the passage of ice at a higher level than that of
the detritus, whose interlacing mounds enclosing small pools or
peat-pots are disposed without any order.
Between Firthy Brig Head and Loch Craig the rock-terrace for-
merly mentioned passes northwards, and dips, first gently, afterwards
rapidly, into Upper Talla Valley. The irregular surface of the ter-
race, the col, and the slope to the valley are covered with loose grit-
fragments and sandy debris

the glaciated aspect of projecting rocks
is marked, but the crumbling nature of the coarse pebbly grits is
unfavourable for the preservation of striations. They are seen only
in one place, namely, on the west slope a little north of the March-
dyke, on a smooth surface among the loose blocks which strew the
hill-side. The striae run down the valley at a low angle, but their
position, about 50 feet above the watershed, renders it possible that
they may belong to the earlier glaciation.
Fig. 3. — Sketch of Moraines in Upper Talla Valley, seen from
the North*.
The more rapid slope terminates in a marsh, beneath which the
detritus is spread evenly. The marsh lies in an expansion oblique
to the valley, in fact in the N.E. strike of the rocks, since it is hollowed
out of a mass of softer shales, on either side of which are massive
grits, namely, abovo at the slope, and below at Talla Craig, which pro-

By Archibald Geikie, Esq.,