Saarijärvi – a new Cambrian paleontological site at Kilpisjärvi, Finnish Lapland

Y.J. Systra (1), S. Jensen (2) and I.Y. Systra (1)

(1) Department of Mining, Tallinn University of Technology, Ehitajate tee 5, EE-19086 Tallinn, Estonia (systra@staff.ttu.ee), (2) Area de Paleontologia, Facultad de Ciencias, Universidad de Extremadura, E-06071 Badajoz, Spain

The Ediacaran-Lower Cambrian Dividalen Group, occupying an autochthonous position, crops out in narrow SW-NE trending zone, usually < 200 m thick, along the Caledonian front in northern Sweden, Norway and Finland. A detailed description of the geology of the Kilpisjärvi area is given by Lehtovaara (1995 and others). Paleontological finds are not very common in Finnish Lapland.
During field-work in 2003 along the Halti-Kilpis¬järvi hiking route, as part of the LAPBIAT project, abundant trace fossils were found in bedrock fragments in the Duolljehuipojohka stream bed, as well as in situ on the walls of the stream valley.
The oucrop is located 500 m from Finnish-Norway border on the SW slope of Mt. Duolljehuipput. This area is outside the map lists of Lehtovaara (1995). Since the new paleontological site is located 3,5 km from cottages on the Lake Saarijärvi to the NNE, we named it the Saarijärvi site.
A typical section of Dividalen Group consists of a thin basal conglomeratic unit, followed by alternating sandstone and siltstone. In outcrop brownish siltstones prevail (60 %), while andstone intercalations are 1–5 cm thick, sometimes up to 20–80 cm, and often with ripple marks on the upper surface. Cross-bedding in sandstones and desiccation cracks on the top surface of muddy layers were found in other outcrops.
Most of the trace fossils consist of the vertically orientated spiral Gyrolithes polonicus, and large trace fossils with a three-lobed lower surface occur in the upper 2–3 cm thick zone immediately below the sand¬stone horizons. The trace fossils at Saarijärvi are forms widely encountered in pre-trilobite Lower Cambrian strata of Baltica.
Field work was done with financial support of the LAPBIAT grant HPRI-CT-2001-00132.

Lehtovaara, J.J. (1995). Kilpisjärven ja Haltin kartta-alueiden kallioperä. Geol. Survey of Finland, Espoo, 1–64