Rit (Vísindafélag Íslendinga) - 01.06.1923, Page 103

Summary of ihe Contents.
Old sea-deposits in Borgarfjörður and Hvalfjörður.
1. Introduction. (pp. 1—5).
Various geological appellations occurring in the following
article are here enumerated and their designations ex-
plained.
2. Description ofthe old marine deposits, (pp. 5— 56).
a) Marine deposits at Norðurá (river), (pp. 5—10).
The deposits left by the sea in the Norðurá valley by
the banks of Norðurá are described in this chapter. The
author here discovered some gravel ridges with stones
worn by the surf about 80 m. above sea-level. They must
have been formed during the great subsidence of the land
that took place here at the end of the Ice Age. The sea
then penetrated into the Norðurá valley, probably as far as
the farms Hvammur and Krókur. Strata of laminated clay
are to be seen very frequently in the banks of the river,
and the author discovered some old sea-shells in clay strata
at the mouth of the valley near Munaðarnes and Brekku-
vað 20 — 27 m. above sea-level, (11 species, enumerated on
pp: 8—10); also at Nautsbrekka near Stafholt, 10 — 12 m.
above sea-level, (6 species; p. 11).
7*