Rit (Vísindafélag Íslendinga) - 01.06.1975, Page 14

the flat valley bottoms or around lakes and ponds, whereas soligene
mires slope more or less. Occasionally a mixture of the two main
types occurs in the same tract of mire.
The majority of Icelandic mires is soligene. Yarious flói (level
mire) areas, however are topogene, e.g. in the lowland areas of
Southern Iceland, in Mýrar and at Snæfellsnes, Melrakkaslétta and
in Fljótsdalshérað. Several highland flói tracts also helong to this
category. The alluvial mires (flæðimýrar) have the characteristics
of hoth soligene and topogene mires although they should rather be
classified as topogene.
The other soligene mires may vary according to location and in
those parts of the country where precipitation is heaviest, e.g. in
Southern Iceland, they may bear a certain resemblance to ombro-
gene mires, although I would consider them a part of the oceanic
phase of soligene mires (Fægri, 1934, p. 8), but mires in drier areas
could then rather be classified under the subarctic phase.
Peat Formation
Peat formation in Icelandic mires varies a great deal. In extensive
mire tracts there is no peat formation at all. This is tlie case for
example in the alluvial mires. In the highland there is generally
little peat fonnation, and where it exists at all the plant remnants
in the peat are only slightly transformed and the texture of the peat
is loose. In the sloping mýri on hillsides with a considerable incline
the peat formation is almost non-existent. Where peat occurs its
thickness varies substantially, 0.5-3 (4) metres is most common.
Still there are examples of much thicker layers even up to 6—8
metres, which is rare and then only in limited areas. In most parts
of the country the peat is rich in ashes, since it contains a wealth
of minerals, which are traceable to two different sources, i.e. vol-
canic ashes and wind blown deposits. The peat in the westem parts
of the country especially in the Westfjords is lowest in ash con-
tent. There almost no drift deposits and no noticeable volcanic ashes
coincide. By far the richest in minerals are the tuff districts in
Iceland, since they also contain more sand and wind blown clay
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