Náttúrufræðingurinn - 1986, Page 6

SUMMARY
The lava flow at Lambagjá
by
Jón Jónsson
National Energy Authority
Reykjavík
Four different lava flows appear to the
west of Staður in Grindavík (Fig.l). The
oldest one is the Sandfellshæð lava, then
the lava flow at Lambagjá, Rauðhóls lava
and the youngest Eldvörp lava is 2150
years old (C14).
The lava flow at Lambagjá together with
the Sandfellshæð lava are fractured, but no
fractures appear in the two youngest lavas.
The lava flow is tholeitic, 5-6 m thick and
very peculiar in structure, consisting of
porous lava fragments, 15-25 cm thick.
The surface of the lava is covered with
heaps and mounds. The authors opinion is
that altogether this indicates that the lava
has been extremely hot, very thin and with
high gas content. Between two phases in
the eruption a thin crust has been formed
and later broken and heaped up.
The orgin of the lavaflow at Lambagjá
has not been found yet and is most likely
covered by the younger lavas.
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