Rare-earth elements in Precambrian iron formations in Väyrylänkylä, South Puolanka area, Finland

Iron formations: A global record of Neoarchaean to Palaeoproterozoic environmental history

“…2.10 Ga, small Algomatype IFs were deposited in several basins in North America (e.g., Homestake Iron Formation, Black Hills, South Dakota; Frei et al, 2008) and Finland (Paakola, 1971;Laajoki and Saikkonen, 1977).…”

7.7 The Earliest Phosphorites: Radical Change in the Phosphorus Cycle During the Palaeoproterozoic

“…In the Finnish part of the shield, phosphorites associated with the organic-rich siliciclastic and carbonate sediments are commonly uraniferous, and many of these occurrences have been revealed and characterised in connection with uranium prospecting (Laajoki and Saikkonen 1977; Ä ik€ as 1980, 1981). However, fluorapatite bands associated with organic and sulphide-rich banded iron formations in the Kainuu Schist Belt are typically non-uraniferous (Laajoki 1975;Geh€ or 1994). The REE characteristics of these phosphate-rich horizons are consistent with their formation in a marine environment (Laajoki 1975;Rehtij€ arvi 1983;Geh€ or 1994 (Melezhik andPredovsky 1978, 1982;Melezhik 1992).…”

“…However, fluorapatite bands associated with organic and sulphide-rich banded iron formations in the Kainuu Schist Belt are typically non-uraniferous (Laajoki 1975;Geh€ or 1994). The REE characteristics of these phosphate-rich horizons are consistent with their formation in a marine environment (Laajoki 1975;Rehtij€ arvi 1983;Geh€ or 1994 (Melezhik andPredovsky 1978, 1982;Melezhik 1992). These phosphatebearing concretions occur in the Il'mozero Sedimentary Formation ( Fig.…”

The Central Puolanka Group - a Precambrian regressive metasedimentary sequence in northern Finland

“…The lowermost parts of the group and the associated paragneisses have been described in Finnish by Korkiakoski (1981Korkiakoski ( , 1982 and Taikina-aho (1982), respectively. The reader interested in the Precambrian geology of Puolanka in general is referred to the earlier papers (Laajoki 1973, 1980a, Laajoki and Saikkonen 1977 and to a recent review (Laajoki in prep. ) and the references in it.…”