Acta naturalia Islandica - 01.02.1946, Blaðsíða 13

ORIGIN OF THE BASIC TUFFS OF ICELAND
7
fellsnes peninsula seemed to place his main con^lusions — the build-
ing up of the uppermost part of the basalt plateau and the vast
younger rocks in Quaternary times — beyond any doubt. Nevertheless
some difficulties have been felt in connexion with this system, al-
though at the present time it is generally accepted.
Thoroddsen accepted Pjeturss’ moraines as genuine, but he never
accepted his system as a whole, as is clearly seen in his compendium
of 1906. As a compromise, he put the moraines into the uppermost
part of the Palagonite Formation. This view is, however, not compat-
ible with the acceptance of the moraines as genuine, but it is
nevertheless of interest to notice that Thoroddsen at last, with re-
ference to Pjeturss’ work, assumed the youngest part of the Pala-
gonite Formation to be of Quaternary age.
Before Pjeturss, K. Keilhack3) had already in 1883 found con-
glomerates of a morainic appearance in the Palagonite Formation,
but refrained from the assumption of a glacial origin:
„und so gross ist die Áhnlichkeit mit der Structur der recenten
Endmoránen, dass man nur bei Erwágung des tachylytischen Binde-
mitteis dieser Conglomerate und der daruber lagernden Hunderte
von Metern máchtigen Complexen von Basalten und geschichteten
Tuffen sich des Gedanken erwehren kann, dass diese völlig structur-
losen Massen Producte der Gletschertátigkeit sind.”
In a much later paper, however, Keilhack abandons this hesitant
attitude and fully accepts Pjeturss’ interpretation of the old con-
glomerates.4)
G. G. Bárðarson in 1929 emphasized the enormous bulk of the
Quaternary strata of Iceland as compared with those of Scandi-
navia. He concluded that certain glacial strata in Snæfellsnes must
be very early Quaternary „and it is doubtful whether simultaneous
glacial strata are found in other countries.”5)
It is of interest to notice here the changing opinions as to
moraines embedded in the top of the basalt plateau at Fnjóskadal-
ur in Middle Northern Iceland.
In the original report6) on old moraines in this area in 1905,
Pjeturss assumed a Middle Tertiary age for these moraines because
of their apparent relation to the Pliocene Mollusea of Tjörnes. These
moraines, as well as the accompanying basalts, are, however, accord-
ing to Pjeturss, very similar in appearance to those in Hreppar in
Southern Iceland, but there the conglomerates were considered as