Rit (Vísindafélag Íslendinga) - 01.06.1923, Blaðsíða 119

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the south of Faxaflói, the author found some sand layers
witli fossil shells in a submarine bog, visible at very low
tide, which the sea had cast up over the bog while it was
in the process of formation.
Nassa incrassata, Ström, was very common in these
strata and Hclix hortensis, Miiller, was also found there.
The former species is common on the south coast of Ice-
land to the south of Reykjanes, and is also to be found,
though very rarely, on the south of Faxaflói, where the
temperature of the sea is greatest. Specimens of the latter
species have not been found alive on the north of Reykja-
nes, but it lives on the south of the peninsula. This indic-
ates that when the submarine bog was formed and the
coast line stood at its lowest point in Faxaflói, the climate
was as warm or even warmer than it is now.
ö. After this submarine bog was formed the land again
subsided and the coastline rose, until it reached its present
level (No. 6 in Fig. 8).
There are indications that this subsidence of the land
still continues gradually at the present time in Faxaflói. No
change is known in the sea temperature or the climate
during this period.
Investigations which have been made in Breiðifjörður
(O. O. Bárðarson, 1921) show that a corresponding land
subsidence took place there, Iate in the Glacial Period, as
in Faxaflói (No. 1 in Fig. 8). The coast-line stood at first
as low or lower than at present, and at the same time the
glaciers covered the low-lying country. Later on the land
subsided and the coast-line rose until it reached at least
80 m. higher than at present.
In clay strata that were formed during the first part of
this subsidence at Saurbær, in Gilsfjörður, shell strata have
been found 2 — 30 m. above sea-level containing the high-
arctic species Portlandia arctica Gray, Niicula tenuis, Mont.
var. expansa, Reeve etc. These strata. were formed close to
the edge of the glacier, first in shallow water and later on
8*