OUTLINE OF ITS GEOLOGY. I53
preserved tusk of the mammoth-an extinct hairy elephant-was disinterred
from the deposit.
Above the till lie accumuIations of sand and gravel, sometimes forming
the remarkable ridges known in Scotland as Kames. Good examples may
be seen between Burdiehouse and Lothianburn. Towards the sea-margin,
deposits of fine laminated clay occur, sometimes curiously contorted, as
if from the stranding of heavy icebergs when these clays were under the
sea. Foraminiferze and marine shells occur in the clays, together, sometimes
with quantities of drift-wood. The brick-pits of Portobello afford good sections
of these latest members of the glacial drift series of this neighbourhood.
At the close of the Ice Age our land was not so much out of water as it is
now. It has since then been pushed up several times, the intervals of rest
between these upheavals being marked by the lines of terrace known as Raised
Beaches. The most marked of these lines near Edinburgh is the twenty-five
foot terrace which forms a noticeable feature of the coast-line. It is well seen
between Granton and Newhaven, and again between Leith and Joppa. When
the level terrace is dug up it is found to consist.of layers of gravel and sand
like the deposits of the present beach, often with abundant shore-shells of the
common species. Here and there, as between Leith and Portobello, the inner
edge of the terrace is marked by a line of bluff or cliff. This represents the
bank against which the waves beat when the terrace was formed.
These deposits, together with the accumulations of peat and mar1 by which
former lakes, like those once covering the Meadows, have been filled up,
close the long geological record, and bring us into the time of the human
occupation, where the stone hatchet, flint arrowhead; and rude canoe are fossils
claimed alike by the geologist and the antiquary.
NEWHAVEN PER.
U
