THE SVINAFELL LAYERS 383 



Altimeter), but the figures for the altitudes should not be regarded as exact. 

 In the section we find the following layers : 



A. Sediment mostly covered by scree. Where visible it is like layer B, 

 although more yellowish-brown in color. 



B. "Lower gray layer". Mainly consisting of thin (2-3 mm) silty-clayish 

 strata; here and there fine-sandy strata, about 1 mm thick, are inter- 

 calated. The color of this layer and layer E is more grayish than that of 

 the rest of the sediments, which are more or less yellow-brownish. 



C. Layers, 10-50 cm thick, of fine-banded silt alternating with unhanded 

 fine-sandy layers. 



D. Unhanded, fine-sandy layer. 



E. "Upper gray layer". As to color and banding very similar to layer B. 



F. Like layer C. 



G. Alternating fine-banded and unhanded layers. Average thickness of the 

 unhanded ones about 0.5 m. 



H. Unhanded except for three fine-banded layers about 0.5 m thick. Grain 

 size of unhanded sediments gradually increasing upwards from fine to 

 about medium sandy. 



L Unhanded sediment, medium to coarse sandy, with embedded layers of 

 gravel, 5-15 cm thick, and scattered rounded stones the size of a clenched 

 fist. 



J. Tillite. 



K. Basalt-globe breccia. 



In Breidagil and adjacent ravines the layers are fine-banded from the lowest 

 visible base to the tillite-covered erosion surface. Here the rhytmites are more 

 regular than in Snidagil. yet hardly regular enough to be described as varves. 

 The gray layers are discernible here also and at practically the same height as 

 at Snidagil. In the steep-sided Godagil ravine the layers from the base 

 upwards are considerably coarser, mainly sandy, yet here and there one 

 finds thin lenses and even angular fragments of finely banded and silty material 

 of the same type as farther south. There are also thin layers of gravel and 

 scattered rounded stones up to 15 cm in diameter. 



Just north of Skjolgil the base of the strata is about 260 m above sea level 

 and the layers about 15 m thick, the contact with the overlying tillite being 

 just about 5 m higher than in Snidagil (PI. IV). Here the layers consist 

 mainly of sand and rounded gravel with distinct current bedding. On the 

 whole we thus find an increasing coarseness of sediment both upwards and 

 towards the north and it seems to have been transported from the north to a 

 lake that was gradually filling up. 



According to the preliminary microscopic studies carried out by Th. 

 Einarsson, the fine grained facies of the Svinafell layers show a microscopic 

 banding. The felspar crystals (labradorite-bytownite), on the whole, lie 

 horizontally. The sediment contains some olivine and occasional grains of 



