Jökull - 01.12.1985, Page 19

The outermost zone A is the least well defined. At
most it is about 2 km wide, running from Straumnes
southeastwards to a position 4 km northwest of Ritur. It
has a semicircular appearance, with its concave side
towards Adalvík. The water depths on the banks are
33—40 m, whereas immediately inside the depths are
between 42 and 44 m and outside between 42 and 47 m.
Some 2—3 km inside zone A there is another zone
with shallow banks, zone B. It is narrower than zone A,
only 0.5-1.0 km wide, and runs from Látrafjall south-
westwards to Ritur. It is also semicircular with the
concave side towards Adalvík. The water depths on
these banks are between 16 and 22 m. Inside depths are
between 25 and 31 m and immediately outside between
24 and 36 m.
What these banks are made of is not known, but their
semicircular appearance, with the concave side towards
land, seems to suggest a glacial origin. It should also be
noted that zone A is „anchored“ with its northern flank
at Straumnes, whereas zone B is „anchored“ in a similar
way with its southern flank on Ritur. Accordingly both
zones lie in positions where the lateral confinement of a
glacier advancing seawards from Adalvík would dimin-
ish drastically. Any further advance beyond each of
these positions would need a greatly increased supply of
Fig. 8. Logs of the coastal cliff section 1 in Haelavík and
a section from within the Stadarvatn terminal moraine
zone. 8. mynd. Jarðlagasnið 1 frá Hœlavík og jarðlaga-
snið frá jökulgarðinum við Staðarvatn.
Fig. 9. Section 1 in Haelavík. The boundaries between
the lower till, the marine silt (3 m) and the upper till are
shown by arrows. Note the concentration of boulders
within the silty matrix in the upper part of the lower till,
interpreted as a waterlain part of the till. 9. mynd.
Jarðlagaskipan í sniði 1 í Hælavík. Jarðlagamót merkt
með örvujn. Takið eftir fjölda hnullunga í efsta hluta
neðra jökulruðningsins.
ice compared with what was needed for the advance up
to these positions. Also, at the zone A position, the
glacier in Adalvík may have coalesced with the glacier
coming out of ísafjardardjúp. This can be inferred from
the way in which the banks constituting zone A end
towards the south - without any obvious „anchoring"
point.
Zone A lies 2-5 km inside the outermost position of
the ice front, as it was calculated using plateau surfaces
unaffected by glacial erosion as upper limits for ice
thickness (Fig. 5). However, as that position is very
tentative and based on the very maximum concept, it is
JÖKULL 35. ÁR 17