Rit (Vísindafélag Íslendinga) - 01.06.1923, Side 117

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(Nos. 25 — 27) were probably formed. They indicate a similar
sea temperature to that now found on the west coast of
Greenland (Sipho togatus, Astarte Banksii, var. Warhami
etc.). The coast-line then was possibly abt. 50 m. higher
than at present. When these strata began to be formed near
Akranes, the glaciers still covered the low-lying ground in
the Borgarfjörður district, so that it was not possible for
strata with similar fauna to be deposited there at that time.
At a later period the glaciers receded from the low-lying
districts of Borgarfjörður- to the valleys, but they probably
remained stationary for a long time at the entrances to the
valleys and piled there up terminal moraines. As the glaciers
melted, tlje land subsided, until the highest coast-line was
reached (abt. 80 — 100 m. above present sea-Ievel).
2. There is no doubt that the coast-line remained stat-
ionary for a considerable period at the highest limit (No.
2 in Fig. 8), for the sea has there in many places formed
broad surf-ledges in the solid rock ánd extensive terraces;
the latter especially at the entrances to the present valleys.
At the same time the ice-boarder receded from the valleys,
at any rate to some extent, so that the sea was able to
íorm marine terraces there.
3. Subsecjuently the land began to rise, so that the sea-
board receded from the highest limits, probably withoul
interruption, down to 40-50 m. above present sea-level
(No. 3 in Fig. 8).
There is no doubt that some of the strata in the marine
terraces in Borgarfjörður were deposited durlng the periods
mentioned, but it is not easy to distinguish between them
and other strata which have been deposited since. None of
the shell strata that were found at Borgarfjörður can be
stated with certainty to belong to these periods, except
perhaps the shell-bearing gravel and clay strata, lowest
down in some of the marine terraces (e. g. Neðranes). It
is nevertheless more probable that they are of a later date.
4. Either the coast-line remained stationary for a long
time at the 40-50 m. limit, or else it first receded con-
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