Full resolution (JPEG) - On this page / på denna sida - First part - I. Physical Geography - 3. Geology. By E. Erdmann, Ph. D., State geologist, Stockholm
<< prev. page << föreg. sida << >> nästa sida >> next page >>
Below is the raw OCR text
from the above scanned image.
Do you see an error? Proofread the page now!
Här nedan syns maskintolkade texten från faksimilbilden ovan.
Ser du något fel? Korrekturläs sidan nu!
This page has never been proofread. / Denna sida har aldrig korrekturlästs.
GEOLOGY.
47
part oi Skåne. Probably at the same time, eruptions occurred in
Småland at the locality where now lake Mien is situated, and in
Helsingland in the district of lakes Dellen. In both places volcanic rocks
are found, rhyolite in the former, andesite in the latter place. The
nephe-line syenite and the interesting melilite basalt in the neighbourhood of
Sundsvall (Alnö) are also regarded as later than the Cretaceous period.
Trollhättan Falls.
The bedrocks of Sweden mentioned above are to a large extent
covered by moraine matter, gravel, sand, clay, and other accumulations,
deposited during the period following the Tertiary and continuing up
to the present time, viz. the Quaternary. Even before the end of the
Tertiary period a deterioration of climate had taken place all over the
northern hemisphere; it reached its maximum during that part of the
Quaternary period which is named the Glacial. At that time glaciers
spread from the highest parts of Scandinavia, gradually uniting so as
to form an immense ice-sheet — a land-ice — which finally, perhaps after
thousands of years, covered not only the Scandinavian peninsula, but
also a great part of northern Europe. These glaciers and this land-ice
swept before them and carried away such detritus as had accumulated
during preceding geological periods. The surface of the underlying
rocks was also to a certain degree worn, smoothed, and striated by
means of stones and gravel carried along underneath the ice.
<< prev. page << föreg. sida << >> nästa sida >> next page >>
