blockfördelning kring bergkullar i mellersta halland - Göteborgs ...

Abstract
Hilly relief and boulder distribution in central and southern Halland
This study is about the formation of the hilly terrain cut into Precambrian rocks in central and
southern Halland, southwest Sweden. In order to increase the understanding of how these
landforms have developed, boulders and weathering forms on two residual hills were mapped.
The hilly relief in Halland is interpreted as sub-mesozoic as the Precambrian rock is covered
with mesozoic sedimentary rock in Skagerack and Kattegat. In addition outliners of
cretaceous limestone have been found south of Falkenberg and remnants of kaolin-rick clayey
saprolite have been found close to Varberg. In northeast Skåne residual hills in Precambrian
rock with weathering forms, emerge from below a cover of cretaceous limestone. Parts of the
bedrock relief in Halland reminds very much of that in northeast Skåne.
The two residual hills investigated in this study have lots of boulders in connection to the
hills. Rock outcrops, boulders, steep rock slopes and different weathering features have been
mapped in the field with a GPS. The data was processed in a GIS-program (ArcMap) which
resulted in maps of the study areas. The landforms found in the study areas have been
compared with stratigraphically well-constrained landforms described earlier in northeast
Skåne.
Both investigated areas shows weathering forms that resemble those in northeast Skåne.
These similarities indicate that the forms in the investigated areas have developed in the same
way as in northeast Skåne; by deep weathering, probably during the Mesozoic. This statement
is also verified by earlier investigations. There are however alternative interpretations for
some of the forms.
The boulders are distributed in certain directions in relation to the hills. This can be related to
different ice flow directions during, preferably the Weichselian. The results from the
investigated areas confirm earlier investigations that say that there have been several different
ice flow directions in Halland. These different movements have influenced for example
distribution of boulders in different ways over relatively small distances. It is also assumed
that the glacial erosion has been relatively weak.
i