Jökull - 01.12.1982, Blaðsíða 61

Fig. 9. The southern bank of the Tijávidarlækur channel with H3 and H4 in primary and reworked
conditions, on the top of the peat series with H5. Springs should be seen at the contact between the H4
and the peat.
Mynd 9. Suðurbakki Trjáviðarhekjar með H3 og H4 ásamt áfokslögunum. Undir H4 er mórinn með H5. Lindir ettu að
sjást á mórkum H4 og mósins.
1944). In the 18th and 19th centuries, soil erosion
set in and the Þjórsárdalur was denuded. The same
applies to the Trjáviðarlækur basin, which is a part
of the Þjórsárdalur valley. This time the erosion was
mainly due to action ofman, and climatic deterior-
ation, but the eruptions in Hekla in 1693 and 1766
dealt the final blow.
At present the Trjáviðarlækur basin is barren
except for poor and scattered remnants of crooked
birch bushes which can be found on slopes adjacent
to Búrfell, and grass pastures which have been culti-
vated by the owners of the power plant to stop the
sanddrifting.
REFERENCES
Einarsson, Th., 1962: Vitnisburðurfrjógreiningar um
gróður, veðurfar og loftslag á Islandi. Tímaritið
Saga, p. 442-469.
— 1968: Jarðfræði. Saga bergs og lands. Mál og
Menning, 335 pp.
— 1975: Um myndunarsöguíslensksmýrlendis. In:
Votlendi, Rit Landverndar 4:15-21.
Einarsson, Th. and Tómasson, H., 1962: Búrfell. Gen-
eral Geology. Report from the State Electricity
Authority, 33 pp.
Jakobsson, S. P., 1979: Petrology of Recent Basalts of
the Eastern Volcanic Zone, Iceland. Icelandic
Museum of Natural History, 103 pp.
Kjartansson, G., 1943: Árnesingasaga. Yfirlit ogjarð-
saga. Arnesingafélagið í Reykjavík, 250 pp.
Kjartansson, G., Thorarinsson, S. and Einarsson, Th.,
1964: C14 aldursákvarðanir varðandi íslenska
kvarterjarðfræði. Náttúrufræðingurinn 34:97-
145.
Larsen, G. and Thorarinsson, S., 1977: H4 and other
Acid Hekla Tephra Layers. Jökull 27:28-46.
Thorarinsson, S., 1944: Tefrokronologiska studier pá
JÖKULL 32. ÁR 57