block with breccia
Characteristic in the rock type breccia is that it consists of
larger, angular rock fragments in a finer grain mass.
The larger pieces in this block, that is divided into two halves, is a kind of diabase, which is surrounded by a grayish
granite, older than the common Bohus granite.
The block has the same appearance as the bedrock of the Pater Noster off
Marstrand in the southern part of Bohuslän. Perhaps it has been transferred to Stångehuvud
frozen in ice during deglaciation.
Parts of the erratic block are overgrown with crustose lichens of various types.
How the boulder has been divided into two halves is unknown.