Jökull - 01.12.1982, Blaðsíða 115

Fig. 5. Geological features of
the area. Basement rock shad-
ed.
Mynd 5. Drœttir íjaröfrœði mœl-
ingarsvœðisins. Svœði með storku-
bergi mzrri yfirborði eru skyggð.
Ung skástíg misgengi tengja Húsa-
víkurmisgengin við Flateyjarmis-
gengi.
from the rivers emptying intothe bay, the Laxá on
the eastern side, and particularly the glacial Skjálf-
andafljót on the western side.
It is worth pointing out that this youngest se-
quence is cut by faults as illustrated on profiles I, J,
I-, and Fig. 5. The faults occurbetween the Húsavík
faults and the Flatey fault and indicate postglacial
movements on this fault system. Their strike is
slightly oblique, or en echelon to major faults,
which suggests a component of right-lateral strike-
slip movement. Structural deformation on land
south of Flatey and evidence on the Húsavík faults
support this view (B. Voighl,pers. comm. 1982).
acknowledgements
I thank the captains andcrews of the ,frni Friðriksson”
and „Dröfn”. Pórður Sigurgeirsson kept the instruments
going, and Guðrún Helgadóttir and Hallur Porsteinsson
assisted wilh laboratory work and drafting offigures. Barry
Voight, Kristján Sœmundsson and Guðrnundur Pálmason
gave much useful advice.
REFERENCES
Aronson,J.L. and K. Saemundsson 1975: Relatively old
basalts from structurally high areas in central
Iceland. Earth Plan. Sci. Letters 28: 83-97.
Birgisdóttir, L. 1982: Ágrip af niðurstöðumjarðfræði-
kortlagningar á Flatey á Skjálfanda og Húsavík-
Reykjahverfi. National Energy Authority Re-
port 0S82018/JHD02 B, 24 pp.
Einarsson, Th. 1968: Jarðfræði, saga bergs og lands.
Mál og menning, Reykjavík, 335 pp.
Eiríksson J. 1980: Tjörnes, North Iceland: A biblio-
graphic review of the geological research history.
Jökull 30: 1-20.
McMaster, R.L.,J.-G.E. Schilling andP.R. Pinet 1977:
Plate boundary within Tjörnes Fracture Zone
on the northem Iceland’s insular margin. Nat-
ure 269: 663-668.
Pálrnason, G. 1974: Insular margins of Iceland. In:
Burk, C.A. and Drake, C.L. (eds.): Thegeology of
continental margins, 375-379. Springer-Verlag.
Saemundsson, K. 1974: Evolution of the axial rifting
zone in northern Iceland and the Tjörnes frac-
ture zone. Geol. Soc. Am. Bull. 85: 495-504.
Manuscript accepted 26 April 1982.
ÁGRIP
JARÐFRÆÐI HAFSBOTNS
Á GRÍMSEYJARGRUNNI OG SKJÁLFANDA
Kjartan Thors, Hafrannsóknastofnun
Seismiskar endurvarpsmælingar á hafsvæðinu
milli Eyjafjarðar og Tjörness sýna mikið misgengi
milli Flateyjar og lands, eins og rannsóknir Guð-
mundar Pálmasonar, Kristjáns Sæmundssonar og
fleiri höfðu bent til. Landmegin við misgengið rísa
JÖKULL 32. ÁR 111