52 EUROPE/Timanides of Northern Russia strata of the Pechora Basin (Figure 2) to the foreland fold and thrust belt of the Polar Urals The Phanerozoic cover thickens eastwards into the Uralian foredeep, where the unconformably overlying successions are 10–15 km thick and the character of the underlying basement is unknown However, in some central parts of the Pechora Basin, along NW-trending axes of uplift, the basement reaches to within a few kilometres of the surface and deep drilling (about seventy holes) has succeeded in penetrating the entire cover succession to sample the basement On the basis of this drilling, and also regional potential field (gravity and magnetic) anomaly maps, it has been possible to reconstruct a simple geological map of the pre-Palaeozoic rocks (Figure 3) beneath the Pechora Basin To the east of the Timan Range, three main tectonostratigraphic zones have been recognised The western is referred to as the Izhma Zone and is a direct easterly extension of the Timan Range turbidite assemblages Towards its eastern contact to the adjacent Pechora Zone, it is intruded by granites, mainly of calc-alkaline composition The Pechora Zone is well seen on the potential field maps, it being well defined by a broad belt of NW-trending magnetic anomalies Drillcores show that the Pechora Zone is dominated by volcanic and volcaniclastic rocks, extensively intruded by plutons, mainly of mafic and intermediate composition Calc-alkaline granites also occur in this zone; together with those in the Izhma Zone, they yield ages of 550–560 Ma and apparently date the end of Timanian deformation and metamorphism in this part of the hinterland (Figure 4) Further east, the Bolshezemelskaya Zone also is preserved locally in structural highs, accessible to the drilling-rig Acid volcanic rocks and granites have been sampled here from below the Ordovician unconformity, and somewhat older zircon ages of ca 570 and 620 Ma have been obtained from the latter, along with Grenville-age xenocrysts Previous literature, especially in Russia, contains several different names for the Bol’shezemel’skaya Terrane (e.g., Khoreyer and Novozemel’skaya) of continental blocks inferred (mostly on geophysical evidence) to exist at depth below the Pechora Basin and southern Barents Sea Pre-Ordovician Complexes of the Subarctic Urals The Neoproterozoic complexes of the Pechora and Bol’shezemel’skaya zones, identified at depths of several kilometres beneath the Pechora Basin, strike south-eastwards into the mountain front of the Subarctic Urals Within the Uralian frontal folds and lower thrust sheets, pre-Ordovician formations are exposed Andesitic volcanic rocks dominate these Precambrian rocks in the northern Urals, along strike to the south from the Pechora Zone Further to the north, in the subarctic Urals, a variety of granitic gneisses, granites, and metasediments occur, apparently as a southern continuation of the Bol’shezemel’skaya Zone Isotopic ages are less reliable in these associations, but the presence of Mesoproterozoic metasediments and granites, and unconformably overlying Neoproterozoic siliciclastic (mainly quartzites) and carbonate formations, and acid volcanic rocks, are well documented Early Ordovician conglomerates and quartzites overlie the Neoproterozoic successions with marked unconformity Thus, it can be inferred that a Precambrian complex, differing in age and character from the Palaeoproterozoic and Archaean rocks of the EEC, occurs within the Timanide hinterland, outboard of the Pechora Zone calc-alkaline volcanic suites Polar Urals Figure Pre Palaeozoic basement of the Timan Pechora region North of the Arctic Circle in the Uralide Orogen, Neoproterozoic complexes comprise major components in the footwall to the Palaeozoic ocean-derived allochthons In the core of foreland folds, beneath Ordovician quartzites, a fragmented ophiolite (Enganepe Terrane) has been dated by the U/Pb zircon method to 670 Ma, and is associated with arc