DEGLACIATION IN EASTERN AND CENTRAL ... - arkisto.gsf.fi

DISCUSSION
A hundred hundred years ago, Salpausselkäs Salpausselktis I and 11 II could be traced without without difficulty difliculty from
western westem Finland to North Karelia despite the inadequacy inadequacy of research tools, from
maps to communications. communications. This was possible because, in the supra-aquatic areas of
southern southern Finland, the Salpausselkäs are very distinct, distinct, wide landforms landforms rising above
their surroundings; surroundings; besides, the best roads ran along them. them. No wonder then that
already already in the 18th century, century, Argillander had had been able to unite, not only the various
parts of the Salpausselkäs, Salpausselkäs, but also also those those of the Jaamankangas-YhdyshaIju­
Jaamankangas-Yhdysharju-
Salpausselkä Salpausselkä 11 II chain chain at at a time time when when there were no scientific scientifrc grounds for classifying
these "sandy eskers" or explaining explaining their their origin. origin.
The trouble started in North Karelia, Karelia, where where the the ice-marginal ice-marginal formations are
discontinuous, discontinuous, and sm smaller aller ridges are often often mainly mainly composed of till. Salpausselkä I
has, accordingly, accordingly, not only only one, indisputable indisputable extension.
The main reason for this this change in in the the mode of occurrence of the end moraines
seems to be that the eastern eastern part of North North Karelia Karelia is is supra-aquatic and so
unfavourable unfavourable to the the deposition of major major glaciofluvial end moraines. They tended to
prefer sites with glacial lakes lakes in front front of of the ice. ice. Glaciofluvial marginal plains
continue continue right up up to to the border of the the supra-aquatic area.
The investigation of ofthe the frontal positions positions of ofthe the ice sheet sheet and deglaciation has been
problematic in North Karelia and numerous opinions have have been expressed about the
question in the course course of of this this century. century. North Karelia is also a key area in solving
the relation between between the Salpausselkäs and other other Finnish Finnish end moraines with the
end end moraines moraines in Russian Karelia.
The front of the Scandinavian ice sheet at the time
Salpausselkä I was formed
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In the Kitee-Värtsilä-Tohmajäni Kitee-Värtsilä-Tohmajärvi area, the northeastern northeastern end of Salpausselkä I looks
as if it has been divided into several parallel, but large, large, ice-marginal formations.
This is clearly visible in the the big interlobate interlobate esker at at Peijonniemi, where there are
three successive successive ice-marginal ice-marginal formations formations of some size over a distance of 5 km: the
marginal plains of of Päivärinne and Kaurila-Musko Kaurila-Musko and the Nenosenlampi esker
delta, delta, which is also the youngest. youngest. The 1- kmJong km-long Kiimakorpi ridge extends from the
esker esker delta towards towards the fokälävaara Pykälävaara ice-marginal ice-marginal formation, the southern end of ofthe the
Tuupovaara end end moraine, 5 km away. Hence, the T\upovaara Tuupovaara moraine is at the
so-e same level as the youngest youngest part of Salpausselkä I.
Judging by the the general trend of the outermost outermost parts of salpausselkä Salpausselkä I land and the
striations, striations, the search for the extensions should should start in in the northeast or northnortheast.
There There is no distinct continuous continuous chain of end moraines in that direction.