Structural evolution of the Vuotso area, Finnish Lapland

Abstract

The Vuotso area is structurally interesting because the fold interference pattern in rocks of central Lapland changes into thrust-related foliation of the Lapland Granulite Belt. A felsic volcanic rock yielded a 2.45 Ga age and conformed that the volcanic rocks in the Vuotso area are (mainly) Paleoproterozoic. A structural sequence with recumbent F2 folding and predominant S2 foliation, and an interference pattern of F3 and F4 foldings could be discerned in the supracrustal rocks. A large D3 antiform is overprinted by mafic-intermediate gneisses that form the basal part of the thrust sequence. The curving of late D3 shear zones suggests that D3 deformation may be associated with thrusting from east-northeast, but thrusting of the granulites and adjacent mafic-intermediate gneisses to their present position is interpreted as a post-D3 event.

Keywords

• structural geology
• structural analysis
• granulites
• gneisses
• metavolcanic rocks
• absolute age
• U/Pb
• Paleoproterozoic
• Vuotso
• Lapland Province
• Finland