A feldspar-porphyric Svecofennian rhyolite associated with Mn-mineralisations at Ultevis, west of Jokkmokk, northern Sweden, has been dated to 1872 ± 9 Ma. This figure also gives a maximum age of deposition of the stratigraphically overlaying sedimentary rock sequence (the Snavva–Sjöfall group). The position of Mn-Fe-Ba-As-F-U-(W-Mo) mineralisations is discussed in relation to the transition from volcanic to sedimentary environments in the Tjåmotis–Ultevis area.