Rit (Vísindafélag Íslendinga) - 01.07.1962, Page 79

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are sub-angular or somewhat rounded and clearly worked by
wind and possibly there has been some water transport. The
stratification shows that this is not solifluction material.
In part these layers are covered by a hard moraine, before
the deposition of which the sediments had been much eroded.
They reach a thickness of about 40 m in one of the summit
peaks. Here the upper part consists mainly of stratified lapilli
with a dip of 18° (E5°N), but there is an admixture of wind-
transported pebbles.
Erosional remnants of these sediments are common on the
block e-f, and they are seen on block f-g, as will be men-
tioned later.
It is naturally clear that the sediments are older than
the displacement e. Furthermore Ármannsfell cannot have
been the high isolated mountain of to-day when they were
formed. Its surface was a part of a general lower surface
above which the mountain hlock has later risen in several
steps.
The slopes of Ármannsfell are largely covered with a strati-
fied weathering mantle, which at the base consists of blocks
and smaller fragments, broken out of the hard primary tuff-
breccia, but higher is mixed with striated boulders, and the
topmost layers are clearly old hard moraines. The glacier has
not wiped out the original weathering mantle but deposited
additional material. Such a mantle being in part morainic is
common on tuff-breccia mountain slopes in Iceland.
At Bolabás the primary tuff-breccia is seen from 190 to
300 m height. We find nearly horizontal layers of alternat-
ing tuff and breccia of various grades (a very slight dip SE
may be seen). The finer grades are glass fragments, i.e. volca-
nic ash, and the coarser are breccias of fractured bombs but con-
taining also more or less of lava fragments of a size up to 1 m
in diameter. All the material is unworn and is a primary vol-
canic formation. It may originally have been a part of the
near-horizontal tuff-breccia layers of Súlur, although it
should be stated that by the nature of the formation there