Over eighty percent of the world’s energy is supplied by fossil fuels and most of the transport sector is driven by oil. Expanding world economies, especially in Asia, are pressing up the price of most geological resources, particularly oil. With an estimated 20–25% of the world’s yet-to-be-found oil hidden beneath the Arctic continental shelves and ridges (about the same amount as is thought to exist in Saudi Arabia), there is a widening interest today to better understand Arctic geology; to investigate the origin and evolution of the Arctic Basin and better define the sedimentary basins and their hydrocarbon potential. The five High Arctic nations, Canada, Denmark (Greenland), Norway, Russia and USA are preparing claims to the outer parts (further than 200 nautical miles) of the Arctic shelves and into the ridges, in accordance with the United Nations Convention on the Law of the Sea.

Defining the character of the younger sedimentary basins, mostly of Mesozoic–Tertiary age, but some reaching back into the Palaeozoic, is essential for the hydrocarbon exploration. The older complexes forming the “basement” to these basins are also important: they influence the geometry of the basins, their subsequent deformation history and the thermal gradients that drive hydrocarbon production and dispersion in the overlying sedimentary successions.

For the last couple of decades, SWEDARCTIC bedrock expeditions have been analyzing the Palaeozoic and Precambrian evolution of High Arctic Eurasia, from Svalbard to Severnaya Zemlya (Gee and Pease, 2004), to better understand the Uralian, Caledonian, Timanian and older history of the “basement” (figure 1). Recently it has proved possible to include Novaya Zemlya in our fieldwork, by working with the Russian Naval authorities in Murmansk. The fieldwork started in 2004 and is expected to continue in the years to come.

Experience gained in 2004 on the international expedition to southernmost Novaya Zemlya (Gee, 2005) provided the foundation for a more ambitious investigation of the bedrock of northern parts of the archipelago (figure 1). Collaboration with VNIIOkeangeologia (St. Petersburg) concerning the organization established the necessary permissions for the fieldwork in the “open” areas of Novaya Zemlya. VNIIOk also looked after most of the communal logistics and took responsibility for the integration of the land-based work with marine programmes. Transport from Murmansk to and from Novaya Zemlya was on the Russian Navy’s Hydrographic Survey ship Gidrolog and these arrangements were also organized by VNIIOk.

The budget for the expedition was defined in two parts – costs for the ship transport to and from Novaya Zemlya (including move of camps), and other expenses (a miscellaneous group of items, including costs for everything from Russian visa invitations to food, guns, boats, iridiums, etc.). The total budget for the ship time was shared by those concerned with the land and marine science (particularly the foreign geologists and a group of six scientists from KOPRI, the Korean Polar Research Institute) and supplemented by contributions from the St. Petersburg organizations SevMorGeo and VNIIOkeangeologia.

The initial plan for the expedition involved departure from Murmansk on 6^th  (latest 7^th ) August and return to Murmansk on 26^th (latest 27^th ) August. A minimum period in the field was agreed – six full days on the northwestern (Barents Sea) side of Novaya Zemlya and six days on the northeastern side (Kara Sea). One day was reserved for moving camps and an extra day on land was anticipated, assuming the agreed timetable could be maintained.

Departure of the expedition from Murmansk was delayed by bureaucratic problems until 11^th August and accounted for the loss of four full days fieldwork. Despite this delay two camps were established on both sides of northern Novaya Zemlya (figure 2) and the fieldwork was rewarding. We obtained an overview of the stratigraphy, structure and tectonics, collected a wide range of suitable material for laboratory analyses, and we can now read the Novaya Zemlya literature (e.g. Lopatin et al., 2001, Korago et al., 2004 and references) with “opened eyes”. Our Russian colleagues provided outstanding support and made the expedition a greater success than the initial delay of the fieldwork promised. Relationships with the marine scientists were most cordial.

The short time for the fieldwork required that the Bedrock Geology group split into two parts – a larger Younger unit, mainly concerned with the mid–late Palaeozoic successions and an Older unit examining the early Palaeozoic and Neoproterozoic rocks.

Barents Sea camps

After just over three days (ca. 1 300 km) at sea, Gidrolog anchored in Russian Harbour (figure 3) in northern Novaya Zemlya in the early morning of 14^th  August and established the larger of the two camps in abandoned military and meteorological houses. An unfortunate incident with reindeer delayed the start of fieldwork by a few hours. This Younger group was composed of all those expedition scientists whose interests were focused on the Late Palaeozoic successions (Devonian to Permian; also Quaternary).

The work of the Russian Harbour (Younger) group mainly involved studies of stratigraphy and sedimentology, with analysis of depositional environments. The Devonian to Permian sections were examined and measured, with varying levels of detail, depending upon the priorities of the different participants. Samples were collected throughout the succession for petrographic study, clastic sediment provenance, detrital zircon investigations, TOC, apatite fission track analysis, and fluid inclusion analysis. A reconnaissance study of folds, thrusts and other structures was also possible in the short time available.

During the morning of 14^th  August, Gidrolog transported the remaining part of the bedrock geologists north-westwards to Sakharova Bay, where a camp was established that allowed work on the Early Palaeozoic and late Precambrian successions. This Older group concentrated its work to the southern side of Sakharova Bay and also visited Maka Bay for the Precambrian section. It obtained a good general overview of the structural geology and the stratigraphy and sedimentary characteristics of the successions, which are dominated by turbidites and related deep water deposits. A wide range of samples were collected for general petrography and about ten sandstones for provenance studies, particularly the isotope dating of detrital zircons. Dolerite dykes cutting the Early Palaeozoic succession were also collected for petrology and isotope dating.

Move to the Kara Sea coast

On the morning of August 19^th , Gidrolog collected the Younger group from Russian Harbour and thereafter the Older group from Sakharova Bay. Waves on the beach and a substantial swell off-shore made the second withdrawal more strenuous. An intended pause of half a day at Inostrantseva Bay to examine sections from the Early Devonian (with bitumen seeps) down into the late Precambrian was abandoned due to the adverse weather conditions, and the ship continued eastwards to round the eastern end of Novaya Zemlya and then turn south and south-westwards for the two camps on the Kara Sea coast. Disembarkation there started at 17.00 on 19^th  August.

Kara Sea camps

Two camps were established on the northern Kara coast, at Oleninskaya Point and Mutafi Bay. The former allowed the Older group to study sections from the Late Cambrian to the Devonian, and the latter placed the Younger group in the Devonian to Permian sections.

The Older group examined the Late Cambrian to Early-Mid Ordovician section along the Neblyuinaya River and the coast section southwards from Oleninskaya Point to Eks Bay, which also included the Late Ordovician to Devonian. The entire section up into the Early Silurian appears to be turbidite dominated with associated deep marine conglomerates and an olistolith. In addition to many samples for petrography, twelve samples of sandstones were collected for provenance (zircon) studies, complementary to the sample collections at the first camp and representative of the entire stratigraphic section from the Late Cambrian to the Devonian.

The Younger group in Mutafi Bay studied the Devonian to Permian sections in the area north of the camp and also to the south on Cape Spory Navolok. A range of samples were collected for purposes similar to those in the Russian Harbour area.

The two groups in the Kara coast camps were collected on the afternoon-evening of 23^rd August, after 3–4 days fieldwork. The ca. 1 700 km journey to Murmansk took four full days and we reached harbour at midnight on 27^th  August.

Geology

Despite the short field-season we obtained invaluable insight into Novaya Zemlya geology (figure 2). This 1 500 km long, 100 km wide archipelago, dominated by two islands (North and South), separates the Kara and Barents seas and two vast and very different hydrocarbon provinces. In the eastern Barents Shelf the gas fields are reported to be comparable in size to those in the North Sea; in the Kara Shelf the oil fields are apparently a direct northerly extension of the West Siberian oil province. Thus Novaya Zemlya defines an enigmatic “barrier” between two geological provinces of global economic significance.

Our field-seasons on southern (2004) and northern (2005) Novaya Zemlya provided sedimentological and stratigraphic evidence of a remarkable contrast in the Early–Mid-Palaeozoic successions, from shallow water shelf in the south to deep marine environments in the north. In the north the turbidite-dominated successions start in the oldest exposed rocks (late Neoproterozoic) and reach into the early Devonian on the eastern side of North Island. Interestingly, the northwestern side of this island (Russian Harbour) provides evidence of some shallow marine and fluvial environments in the Devonian, a possible response to Caledonian orogeny further west.

The structure of Novaya Zemlya is enigmatic and open to very different interpretations. The major anticlinorium that dominates the entire structure (figure 2) is upright to southwest-vergent through much of South Island, apparently in response to sinistral transpression. However, further north and in western North Island, the northwestern limb of the Novaya Zemlya Anticlinorium is broken by several northwest-vergent thrusts. The amount of movement on these thrusts is unknown and the subject of much speculation (e.g. Otto and Bailey, 1995). Relatively short transport is often inferred (e.g. Pogrebitsky, 2004), but long transport (over 100 km) is possible, implying that the entire Palaeozoic complex of North Island could be allochthonous (i.e. that has been moved from its original place). This alternative is illustrated in figure 4 in a northwest-southeast profile through the eastern end of North Island.

There is a clear need for better control of the deeper structure of Novaya Zemlya and its relationship to the surface features. If the thrusts that are mapped on the surface are listric in geometry and related to a major flat-lying thrust zone at depth, this should be identifiable by reflection seismic profiling. The differences between the alternative interpretations of the structure are great and could have profound implications for understanding the distribution of the hydrocarbons.

Comments on other aspects of the fieldwork

The weather was generally unstable, but allowed fieldwork on both sides of the Archipelago. Polar bears were seen on most days; they visited camps occasionally and had to be “moved” off outcrops a few times. This created no major problems, but guns were essential. Walrus were frequently seen along the Kara coast. The expedition participants were looked after well by the Gidrolog’s Captain and his crew, and Dr. Boris Vanshtein did a great job, wedding the land and marine operations and dealing with the Russian bureaucratic structure.