GEOTOURISM A World Renowned Section With relatively easy access from Longyearbyen,the Festningen Section is a very popu- lar geological attraction that displays an almost complete section of sedimentary rocks throughout the Mesozoic.Scientists,students and oil company geoscientists come every year from all over the world to learn basic principles of sedimentology and sequence stratigraphy.
Atle Mørk is Senior Geologist with SINTEF Petroleum Research and has more than 25 field seasons in Svalbard. Photo: Hans Arne Nakrem ) .no .npolar © Norwegian Polar Institute (www
Isfjorden Longyearbyen The Festningen Section Barentsburg Svea
The Festningen Section
An almost continuous section, although folded and partly repetitive, from the Late Permian to the basal Cenozoic is well exposed along the coastal cliffs of the Festningen Section. Organic rich shales that should be considered potential hydrocarbon source rocks occur in the Middle Triassic and Upper Jurassic, while In August,"the Sub- sandstones with reservoir quality are found in the Upper Triassic and Lower Cretaceous. The outcrops thus commission on Triassic constitute important analogues for petroleum geologists exploring the Barents Sea further south. Stratigraphy" have there annual meeting in Longyearbyen. Sandstones of the early Cretaceous Helvetiafjellet Formation that are exposed on the Festningen Islet contin- http://natmus.uio.no/ ue onshore and stand out as a prominent ridge. Dinosaur footprints (mentioned in the text) were first found triassic-2006/ on these beds in the 1960’. Students and professional geoscientists visit Svalbard - and the Festningen Secti- on in particular - because of excellent exposures that are not covered by vegetation.
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Atle Mørk, SINTEF Petroleum Research
he Festningen Section is a world- renowned geological profile with T excellent exposures of sedimentary rocks ranging in age from the Carbonifer- ous to the Cenozoic. Located strategically in the outer Isfjorden of western Svalbard, it is easily spotted by tourists as well as geoscientists on their way by boat to Long- yearbyen, the "capital" of Svalbard and the world’s northernmost city. A continuous section from late Precam- brian to Cenozoic can be studied in this location.This is because it is practically tur- Photo: Atle Mørk ned vertical by folding when Greenland The organic rich and soft Middle Triassic shales ( Bravaisberget Fm) have been strongly folded making strati- and Svalbard collided during the initial graphic studies complicated. phase of opening of the North Atlantic Ocean during the early Cenozoic. Along the shoreline you can walk five km along Section started with the Norwegian oil used for navigation by trappers along the well-exposed coastal cliffs. Harsh winter industry moving into the Barents Sea. Stu- coast in earlier days. Results of the extraor- storms with rough waves and drifting ice dent groups from the universities in Oslo dinary mass extinction at the end of the wash the section clean, and in this way we and Bergen began detailed investigations. Permian can be seen as fossils are sparse in get new, clean exposures every year. The purpose was primarily to understand the uppermost Permian sediments and The section is named after Festningen the sedimentology and depositional histo- almost absent in the lower 100 meters of ("The Castle"), a small islet with a light- ry of the area. This also started the use of the Triassic. Even trace fossils are quite spar- house. It is formed by the indurated Fest- the Festningen Section for excursions se. ningen Sandstone of Cretaceous age that during the short summer from June A major transgression that can be traced consists of river deposits. It is now also through August.Following the universities, all over the arctic, and also globally (see famous for its large dinosaur footprints. the Norwegian Petroleum Directorate visi- article by Ashton Embry in GEO ExPro No. ted the section through several summers, 2/2006, p.26). It occurs at the base of the Dinosaur footprints and thereafter Statoil, Norsk Hydro and Middle Triassic resulting in organic rich, During the early part of the 20th centu- other oil companies as well as IKU (now dark mudstones that has been strongly ry,Norwegian geologists and palaeontolo- SINTEF Petroleum Research) made several affected by the early Cenozoic folding. This gists measured the section bed-by-bed field trips. A series of master and doctor unit forms a major source rock for oil further and collected numerous fossils. Internatio- thesis resulted. east and in the central part of the Barents nal specialists later studied them for the Sea (Steinkobbe Fm). The coastline later purpose of making a detailed stratigraphy. The Paleozoic prograded eastwards and prominent well- The discovery of dinosaur footprints was Carboniferous fluvial conglomerates cemented shallow marine sandstone were made on an international geological field- and some carbonate beds are found only deposited all along western Spitsbergen. trip in 1960 attended by Professor De Lap- locally, but from the late Permian Kapp Sta- parent.Iguanodon was kept responsible for rostin Formation (named after this locality) the traces that were 68 cm long with a dis- and upwards, the section is well exposed. tance between them of 2m showing that Limestone banks with brachiopods form quite a big beast had wandered around in the base of the exposure. The limestones Late Cretaceous time. Casts in plaster were grade into shales found in this deep cold- made of the traces the year after, luckily, as water shelf sediment. Towards the top of the rocks have now fallen down due to the Permian, soft clays silicified by sponge weathering. These casts can be seen at skeletons have produced a glassy unit museums in Longyearbyen and at the Pale- standing out as a peninsula towards the ontological museum in Oslo.When I visited bay eroded into soft Triassic shales. the place 20 years later, new traces - howe- ver not so big and nice - were exposed in The Mesozoic the vertical cliff, and visitors to Festningen The Lower Triassic Vardebukta Formation can still see well-preserved footprints. At is named after the cairn on the coastal cliff the time of formation, the area had already drifted to high latitude indicating that the In Svalbard the polar bear is a constant threat dinosaurs needed to be warm blooded to making it necessary to carry guns. When big groups survive the winter. it is normal to have a guard watch for this very Renewed interest for the Festningen dangerous animal. Photo: Halfdan Carstens
58 GEO ExPro May 2006 CENOZOIC Firkanten Fm. 2200
Carolinefjellet
S Fm. U
O 2000 E Helvetiafjellet Photo: Atle Mørk
Photo: Atle Mørk Helvetiafjellet Fm C Fm. Rurikfjellet Fm A
T The basal Cenozoic conglomerate overlies shallow E marine shelf deposits; tens of millions of years are Festningen Sandstone R missing at this contact. C Rurikfjellet Fm. FESTNINGEN Dark Cretaceous shales are overlain by the fluvial chan- nel deposits of the Fest- ningen Sandstone. C I Photo: Atle Mørk S Agardhfjellet S Fm. 1500 A
R Limestone bank depo- U
J sits formed by phosphatic ooids (inset) demonstrate a Wilhelm¯ya Subg r. high energy period within the
R Middle Triassic. E De Geerdalen P
P Fm. U E L Bravaisberget D Galleries of phosphate nodules, mostly formed Photo: Atle Mørk D
I Fm. as tunnel infillings, and phosphate nodular beds
M 1000 in the organic rich sediments show that life C
I flourished at times between anoxic periods. S S A I Tvillingodden R
T Fm. R Photo: Atle Mørk E W O
L Bivalve (aquatic mol-
lusks) bank deposits Photo: Atle Mørk Vardebukta forms the first mass Fm. 500 occurrence of life in the Triassic. N A I
M Kapp Starostin A major sequence boundary occurs on top of the hard Permian R
Fm. Photo: Hans Arne Nakrem
E cherts that are overlain by soft Triassic shales. P Bryozoans are important fauna elements in limestones 0 of the Upper Permian Kapp m Sst M Si vf f m Cgl Starostin Fm. GEO ExPro May 2006 59 GEOTOURISM
Svalbard Svalbard is an uplifted corner of the Barents shelf made up of islands totalling some 63,000 km2 (the equivalent of more than 10 North Sea quadrants). The main island is Spitsbergen, a name given by the Dutch explorer Wilhelm Barents in 1756 because of its jagged, frost-splintered peaks and valleys submerged in huge gla- ciers, which can be seen far away from the coast. "Svalbard", a name given by the Norwegian Vikings, means the "cold coast". With summer temperatures generally below 10 °C, visitors have no problem in accepting this. However, with four months of 24 hours daylight in Long- Photo: Halfdan Carstens yearbyen (April 22nd to August 22nd), Svalbard also deserves the nickname This section nicely displays a transgression with continental deposits to the right (Helvetiafjellet Fm) and "land of the midnight sun". marine deposits (Carolinefjellet Fm) to the left. It is often said that Svalbard is like a complete geology textbook, neatly repre- A new major transgression took place in million tonnes of coal per year in the mine senting all the formations from the Pre- the Upper Triassic. This was accompanied Svea Nord, while the Russian company cambrian through to the Quaternary. The with a dramatic shift in sedimentation pat- Trust Arktikugol has a far lower output lack of vegetation enables geoscientists to tern. The marine dark sediments were from Barentsburg. An abandoned coal study the rocks with relative ease. Howe- replaced with shallow marine sandstones mine is found a few meters above the base ver, most locations are difficult to access deposited on a shallow shelf.In the Barents of the Cenozoic at Festningen and demon- as there are no roads outside Longyear- Sea, thick deltaic units were formed at this strates early prospecting for this important byen, necessitating transport by boat or helicopter, and the polar bear is a constant time. energy resource. nuisance for tourists and geologists alike. A condensed section of only 20 m thick- Several exploration wells have been ness spans the Triassic – Jurassic boundary Visiting the Festningen Section drilled on the archipelago since 1960. No at Festningen. Further to the east and in Detailed planning is necessary if you discoveries have been made, but good oil the Barents Sea, this unit consists of sand- want to do field work in Svalbard as there is shows were reported in two wells drilled stones with excellent reservoir quality. At no public transport. You will need a heli- by the Russians in the 1990’s and gas Festningen, spectacular conglomerates copter or a boat that can be rented in shows have been recorded in several form the boundaries at base and top. Longyearbyen.The Festningen Section can wells. It is widely believed that Svalbard Above the conglomerates, a thick, dark be reached by boat from Longyerbyen in does not contain significant amounts of shale unit represents the Cretaceous – about 3-5 hours. oil and gas because of tight reservoirs. Jurassic boundary. The Jurassic has abun- The old hunting cabin at the base of the The real value of Svalbard for petro- dant organic matter and is an equivalent to section with scattered Carboniferous leum geologists is excellent outcrops that the Hekkingen Formation of the Late Juras- conglomerates provide a natural harbour can be used as analogues of North Sea sic source rock system in the Barents Sea. at a river outlet. In the Upper Permian and depositional systems and to the geology The Helvetiafjellet Formation at Festning- Mesozoic sections,access is easiest on high of the Barents Sea. en has several distributary channels with tide. Note that access has to be parallel thin interbedded coals and represents the with the strike. If not, your propeller may deltaic environment where dinosaurs wan- map sandstone ridges. dered around. The pioneers of Svalbard used large, sturdy wooden boats when doing field- The Cenozoic work, surely creating hazardous episodes. A major erosional gap spanning 60 – 70 The detailed work they carried out during million years separates the Cretaceous long summers is therefore quite impressi-
sandstones from the basal Cenozoic cong- ve.Even today, with modern rubber-boats Photo: Halfdan Carstens lomerates initiating the last depositional and survival suits, landing can be rough succession on Svalbard. and wet.The reward is, however, worth the The Tertiary is also well known for its effort as the Festningen Section displays With no cays to land for the ships carry- coal beds that have been mined for more one of the most complete continuous sec- ing geoscientists on field trips, it is than 100 years. Today, Store Norske Spits- tions through the Mesozoic anywhere in necessary to have Zodiacs to go onshore. bergen Kulkompani is producing nearly 3 the world.
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