Slätt­ber­gen*

The natu­re con­ser­va­tion area of Slätt­ber­gen in cen­tral Troll­hät­tan con­si­sts of three dif­fe­rent are­as, Eriks­ro­par­ken, Hjort­mos­sen and Sandhem-Halvorstorp.

In the Sand­hem-Hal­vor­storp area we see lar­ge are­as whe­re flat outcrops of bed­rock are expo­sed. In some pla­ces the bed­rock here is more than 1.6 bil­li­on years old! The flat sur­fa­ce (pene­plain) was for­med by ero­sion more than half a bil­li­on years ago. Only very pri­mi­ti­ve forms of life existed then, and the­re was no vege­ta­tion on the Earth. This flat sur­fa­ce is cal­led the sub-Cam­bri­an pene­plain, becau­se it was for­med befo­re the Cam­bri­an peri­od. The pene­plain was then buri­ed by thick lay­ers of sedi­ment from a sea that flooded the peneplain.

The­se sedi­ments have now been com­ple­tely ero­ded away here, but remains can still be seen in the rocks of the tab­le mountains (for examp­le on Hal­le­berg and Hun­ne­berg). In other words you are stan­ding on a flat rock sur­fa­ce that was for­med over half a bil­li­on years ago but which was once buri­ed under deep lay­ers of sedi­ment! At Slätt­ber­gen you can also see tra­ces of the last ice age, when ice and sto­nes gou­ged the rock sur­fa­ce, lea­ving ice groo­ves that show the direc­tion the ice was moving.