Quaternary Deposits/Bedrock

Rationale
By studying the chemical composition and spatial variability of Quaternary deposits (Figs.1,2) or bedrock (Fig. 3), one gets an impression of the natural geochemical patterns upon which any anthropogenic contribution may be superimposed. It is of crucial importance in any environmental investigation to document what the natural elemental levels and variation are, in order to be able to say how significant the man-made overprint really is.

Advantages
Gives the natural geochemical picture.

Drawbacks
Requires digging (deep) through the soil, or (hand-held) drilling equipment to take the samples.
Spatial geochemical variability (horizontal and vertical) can be great (veins, contacts, superimposed tills, ...).

ASSISTED DIGGING TO EXPOSE QUATERNARY DEPOSITS
[cd2-12]
(Photo: G. Kashulina)
Fig. 1: Excavator digging through the deep soil to uncover the moraine deposit to be sampled.

QUATERNARY GEOLOGIST AT WORK (C5)

(Photo: G. Kashulina)
Fig. 2: Excavated pit for study and sampling of Quaternary deposits.

BEDROCK MAP
[GEOLMAP.GIF]
(Map: Ø. Nordgulen)
Fig. 3: Simplified map of the solid geology of the Kola Peninsula, showing various geological terranes. The Varanger and Rybachi Peninsulas consist of Late Paleozoic sedimentary rocks (yellow). Late Archean greenstone belts (pale green) are found at Bjørnvatn, Olenegorsk, and Kolmozero-Voronya. The Keivy terrane is Early Proterozoic in age (blue-green). The Polmak-Pasvik-Pechenga-Imandra-Varzuga-Ust'Ponoy greenstone belt (dark green) is of Early Proterozoic age. Granite and granodiorite intrusions of the Neiden type are shown in dark brown, those of the Nattanen type in red. Paleozoic alkaline intrusions are shown in magenta. Hetta granitoids (light brown) and Jergol gneiss (light orange) are found within the Karelian Province (medium green) near the Finnish-Norwegian border. For more information, consult Roberts, R. and Norgulen, Ø., eds., 1995. Geology of the eastern Finnmark- western Kola Peninsula Region. NGU Spec. Publ., no. 7). Blue stars indicate the location of major townships.