Jökull - 01.12.1993, Qupperneq 43

cm
h 50
Stratified
eolian sand
- 40
- 30
- 20
- 10
- 0
ö . -o
Palaeosoil
Black tephra layer
The Miöfjöröur Tephra
Stratified
sand and fine sand
Cross-bedded
sand and gravel
Figure 8. The sediment succession at the boundary
between the fluvioglacial terrace sediments and the
discordantly overlying channel fill with tephra layers
(cf. Figure 7). — Jarðlagasnið er sýnir skipan jarð-
laga í brún sethjallans við Miðfjörð.
30 m shoreline must be situated roughly parallel to the
isobases and that the main glacial overburden load was
situated to the south-west of there.
The final part of the deglaciation history in the area
comprises a regression of sea-level and withdrawal of
the glaciers towards a few ice-divides or ice-centres
in the mountainous inland parts of the area (Figure 9).
Kjartansson (1955) and later Pétursson (1986, 1991)
reconstructed a major Lateglacial ice-divide above the
central and southern parts of the Melrakkasléttapenin-
sula and the neo-volcanic zone. However, glacial
striae in the southeastern part of the studied area indi-
cate that another ice-divide was situated on the present
water-divide between the Bakkaflói and Vopnafjörður
areas and also in the mountainous southern part of the
Langanes peninsula (Figure 9). Consequently, these
elevated parts of the area most likely hosted the last
remains of the Lateglacial glaciers.
As relevant 14C-datable material has not yet been
found in the study area, the apparent age of the events
Figure 9. Main Lateglacial and early Holocene ice-
divides, regional marine limit and ice-marginal forma-
tions in northeast Iceland. Glacial striae are fromKjar-
tansson (1955), K. Sæmundsson (1977) and Pétursson
(1986). — Helstu ísaskil, fjörumörk og lega jökul-
jaðra á síðjökultíma og í upphafi nútíma á Norðaust-
urlandi. Stefna jökulráka er samkvæmt ritum Guð-
mundar Kjartanssonar (1955), Kristjáns Sœmunds-
sonar (1977) og Halldórs G. Péturssonar (1986).
outlined above can only be suggested by comparison
with 14C-dated events in adjacent areas. The earliest
part of the Lateglacial deglaciation history of northeast
Iceland has been 14C-dated to about 12,700 BP on the
western Melrakkaslétta peninsula (Pétursson, 1991).
We, therefore, assume that present-day dry land in the
study area was first deglaciated at a similar or even
a later date, when scattered shoreline features were
formed at 65 m and 50-40 m a.s.l. in the outer coastal
parts of the area.
A readvance or a standstill of the glacier mar-
gin in the Vopnafjörður area, some 25 km south of
the Bakkaflói bay, has been 14C-dated to about 9700
BP (Norðdahl and Hjort, 1987; Th. Sæmundsson,
1994). At that time the glaciers in the Vopnafjörður
area reached a position some distance inland from the
JÖKULL, No. 43, 1993 41