Jökull - 01.12.1990, Side 41

gional marine limit at 30^40 m a.s.l. Hjartarson et al.
(1981) suggested, that the younger Cirque-glacier
stage occurred in late Younger Dryas or early Pre-
boreal time when relative sea-level had receded below
the 10 m level. Furthermore, they proposed that the
older Valley-glacier stage might correlate with the pe-
riod between 12,000 and 10,000 B.P.
Based on the data collected by Norðdahl and
Einarsson (1988), the course of deglaciation and sea-
level changes in East and Southeast Iceland has been
divided into three successive stages. The oldest
Fáskrúðsfjörður stage represents the first standstill or
readvance of the glaciers recorded on land in East
Iceland since their retreat from the Weichselian max-
imum position on the shelf. Simultaneously relative
sea-level rose to its highest position at about 50 m
a.s.l. at the Fáskrúðsfjörður stage moraines (Fig. 7).
This stage was subsequently terminated by retreat of
the glaciers and regression of relative sea-level. The
second Breiðdalur stage is represented by moraines
which were formed, either during a standstill or a
readvance of the glaciers in the area between Lón
and Norðfjörður, when the ice margin had retreated
to within the present coastline (Fig. 7). Simultane-
ously sea-level rose to a new elevated position at the
Breiðdalsvík; stage moraines. Finally the Berufjörður
stage comprises the third and youngest set of moraines
and raised beaches at the Berufjörður stage moraines
(Fig. 7) (Norðdahl and Einarsson, 1988).
Comparison with the results of Hjartarson et al.
(1981) shows, that the Berufjörður stage correlates
with the Cirque-glacier stage, the Breiðdalur stage
with the Valley-glacier stage, and consequently that
the Fáskrúðsfjörður stage predates the Valley-glacier
stage. The stratigraphical position of the Fáskrúðs-
fjörður, Breiðdalur and Berufjörður stage moraines
and their related marine limits is uncertain so far, as
radiometric dates are still lacking. On basis of paral-
lelism between the above described course of deglacia-
tion and sea-level changes in East Iceland and the one
described by Ingólfsson (1988) in West Iceland the
Fáskrúðsfjörður stage may correspond to the Skipa-
nes event (Older Dryas) and the Breiðdalur stage to
the Skorholtsmelar event (Younger Dryas) (Norðdahl
and Einarsson, 1988).
marine-limit features in South Iceland. Legend: 1) I4C
dates. 2)TheBúðimoraine. —Jökulgarðarog sjávar-
borðsmenjar frá upphafi nútíma á Suðurlandi. Tákn:
1) Geislakolsaldursákvarðanir. 2) Búðaröðin.
SOUTH ICELAND
Since the identification of the Búði stage
(Kjartansson, 1943; 1958; Th. Einarssoni, 1964), the
Búði moraine itself has been subjected to very limited
research efforts. Kjartansson (1958) described the
Búði moraine (Fig. 8) as ”a belt of terminal moraine
ridges“ and later Th. Einarsson (1960) pointed out
that the moraine is a complex of several ridges. In a
seismic study of the Markarfljót sandur area in central
South Iceland an extension of the Búði moraine was
detected 25-50 m below the sandur surface (Haralds-
son 1981). Jóhannesson (1985) emphasized that the
Búði moraine is a complex of up to seven more or
less parallel moraine ridges and speculated that the
outermost ridges of the Búði moraine were at least of
an Older Dryas age (about 12,000 B.P.) and that the
innermost ridges were at least of a Younger Dryas age
(about 10,000 B.P.).
Recently, Hjartarson and Ingólfsson (1988) have,
on basis of substantial stratigraphical and chronolog-
ical evidence, drawn quite different conclusions con-
cerning the age of the complex Búði moraine. Out of
twelve 14C dated samples of marine molluscs gathered
from raised marine sediments in the South Icelandic
JÖKULL, No. 40, 1990 39