Náttúrufræðingurinn - 1971, Blaðsíða 58

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NÁTTÚRUFRÆÐINGURINN
annar, líklegast að Iiér sé um að ræða H3 í öskulagatímatali Sig-
urðar Þórarinssonar, en það lag er 2820±70 ára (Þórarinsson 1967)
samkvæmt C14 aldursákvörðun.
Gígirnir við Lambavatn hafa það ég veit ekkert nafn, en Lamba-
vatnsgígi kalla ég þá hér og legg til, að því nafni verði haldið.
Hraunið má kenna við vatnið og nefna I.ambavatnshraun.
HEIMILDARIT
Thórarinsson, S. (19G7). Tlie eruptions of Hekla 1947—1948 I, Soc. Scient.
Islandica, Reykjavík.
Tómasson, ]. Personal communication 1969.
S U M M A R Y
The Lambavaln Craters
by
Jón Jónsson,
National Energy Authority, Reykjavík.
A previously unknown row o£ craters at Lambavatn, about 3 krn west o£
Laki southern Icelancl, was discovered hy the author in the summer of 1968.
The crater row, which is about 500 m long, seems to be a continuation of a
previously known eruptive fissure nortli of Laki, now mostly covered by the
1883 Laki fissure eruption. The name Lambavatnsgígir (gígir=craters) is
proposecl for these craters. The Lambavatn lava differs considerably from the
1783 Laki lava in having much more abundant olivine (See Table I. No. 1
is the Lambavatn lava, no. 2 the Laki lava from the western part of the fissure,
and no. 3 from the easternmost part of the same lava).
The age of the Lambavatn eruption seems to be more than 2820±70 years
according to tephrochronological observations by Thorarinsson (1967) and
C14 age determination.