Billefjorden Field School 2018

Billefjorden 2018

ARCTIC PETROLEUM FIELD SCHOOL IN PYRAMIDEN, SVALBARD 2018

Short introduction to Svalbard

Svalbard is an Arctic Archipelago located in the NW corner of the Barents Shelf. It is a territory under
Norwegian sovereignty regulated in Svalbard Treaty (Spitsbergen Treaty, Svalbardtraktaten), sign by
46 countries. It allows all the signatories with given equal rights to engage in commercial activities
(exploration and business) on the islands.

The main settlements in Svalbard are: Longyearbyen, Barentsburg, Ny Ålesund, Pyramiden,
Isfjordradio, Hornsund and Hopen.

65% of the land area of Svalbard is restricted area with National Parks and Nature reserve.

During the Fieldschool we will be operating within Area 10, which is not protected area. However the
following rules apply here:

• Do not pick up flowers or any plants
• Do not leave any garbage behind, including a toilet paper
• Do not disturb a wild-life.
• Do not pick up any wooden or metal objects, which appear old. They might be a cultural
  heritage
• Collect plastic waist if you find any along the beaches
• Do not walk alone, stay close to the person with a rifle. If you need some privacy please
  inform the safety responsible.

Introduction to geology of Billefjorden area

Rock record in Billefjorden area covers:

• Metamorphic basement of Hecla Hoek Succession deformed during the Caledonian Orogeny. “The
  basement” is exposed east of Balliolbreen fault.
• Devonian Old Red strata west of Balliolbreen fault deposited in Andrée Land sedimentary basin; later
  the sedimentary rocks in the basin were deformed in latest Devonian /earliest Carboniferous
• Widespread deposits of Early Carboniferous coal- bearing Billefjorden Group deposited in humid and
  warm climate
• Serpukhovian to Moscovian deposits of Billefjorden Trough- a narrow rift basin filled with alternating
  silisiclastics, exaporates and carbonates. Deposition took place in arid and warm climate
• post-rift warm water carbonates and evaporites of Gipshuken Formation overlaid by cold water
  carbonates with cherts of Kapp Starostin Formation

Billefjorden Fault Zone

Billefjorden Fault Zone (BFZ) is a long lived lineament that underwent multi-phase deformation in
different tectonic regimes. BFZ is the boundary between two provinces/terrains with different thermal
history and development. Those provinces were juxtapose during Caledonian Orogeny.

1. BFZ has developed along a sinistral (left- lateral) shear zone associated with greenshist facies
   metamorphism of L. Ordovician -Silurian age developed during the Caledonian Orogeny
2. Devonian collapse of the Caledonian orogen has resulted in formation of a large Devonian Andree
   Land Basin filled with Old Red Sandstone, which is preserved to the west of BFZ
3. L. Devonian/ E. Carboniferous Svalbardian (Ellesmerian) phase:
   Sinistral transpression along BFZ has resulted in folding and thrusting of the Devonian basin fill.

   Large shortening was accommodated along the Balliolbreen Fault, steep fault with 10 km of reverse
   offset expressed as Precambrian metamorphic basement of the Hecla Hoek Succession faulted up on
   top of the Devonian silisiclastics (Fig.)

4. Mid- Carboniferous (Serpukhovian- Moscovian) Billefjorden Trough. In this period BFZ was
   active as normal, down to the east fault zone bounding a narrow rift basin located to the east.
   Billefjorden trough is a world – class half- graben, hosting 2-3 km thick syn-rift succession.
5. Some potential mild tectonic activity along BFZ took place in Triassic, Jurassic and Lower
   Cretaceous.
6. Transpersonal dextral regime in Eocene related with development of West Spitsbergen Fault and
   Thrust Belt has resulted in inversion of the BFZ. Shortening in was partly accommodated by reverse
   movement along selected BFZ segments. Approximately 200m of reverse offset recorded on post- rift
   Permian strata.

Sedimentary fill of the Billefjorden Trough

Pre- rift Billefjorden Group (Fammenian to Visean) consist of clastic sediments with local coal seams
representing delta plain and overbank deposits. The strata are preserved in many locations in
Spitsbergen and are recorded on the Barents Shelf. Accumulation of coal and organic- rich deposits
suggest the deposition in a humid and warm climate, when Svalbard bedrock was located at the
equator.

The Billefjorden Trough has developed in a dry warm climate when Svalbard bedrock was located in
sub-tropical zone and was slowly drifting towards northern latitudes. The climate can be indicated
from abundance of red terrestrial strata, warm water carbonates and thick successions of evaporates
often with chicken-wire structure, that indicate to deposition in sabhka and isolated lagoons.

The Billefjorden Trough deposition begins with the Serpukhovian Hultberget Formation. Red shale
beds alternating with sandstones and conglomerates, traces of rootlets and horizons with caliche
indicate to terrestrial environment with fluvial and alluvial sediments.

Following deposit of lower Ebbadalen Formation, Ebbaelva Member are showing the transition from
terrestrial to marine environment and facies back-stepping pattern due to forced regression. This
interval is silisiclastics-dominated succession with subordinary evaporates (gypsum) and carbonates
representing of variety of facies interpreted as braid river, delta, playa lake, lagoon, shabkha and
shoreface.

Higher in stratigraphy the upper Ebbadalen Formation is represented by alternating dark carbonates
and shales with white evaporates (gypsum) of Trikolorfjellet Member, interrupted by intervals of red
shale. The red shale is likely distal part of red conglomerates and sandstones of Odellfjellet Member,
deposited near the BFZ as large systems of alluvial fans.

Moscovian Minkinfjellet Formation consist of grey carbonates and white evaporates, similar to the
deposits of the Trokolorfjellet Member. These beds are alternating with yellow shoreface sandstones
with tidal indicators and minor alluvial fan deposits near BFZ.

The syn- rift succession is draped by late syn-rift to post-rift warm water carbonates of
Wordiekammen Formation.