Västra Gräddmanhällan, an island in the archipelago of Kalix, the Bothnian Gulf, Northern Sweden, has good outcrops of dolomite and dolomitic limestone in which occur calcareous algae. Other sedimentary deposits here are calcareous quartzitic rocks and a gray slate. The rocks are cut by late dikes of altered ultrabasic rocks of kimberlite type. Local boulders of a brown conglomerate, a brown, altered kimberlite and of a green kimberlite breccia are met with in the Pleistocene beach deposits of the same island.