When, in March 2011, I entered the building of the University Centre in Svalbard (UNIS) my first thought was:"I want to work here". This dream came true only a year later when I started my long but very rewarding journey through the PhD project. Firstly, I would like to thank my supervisor Snorre Olaussen for offered chance to develop this exciting project in Arctic rift basin geology, his patience and trust. Transition from research conducted in structural geology of metamorphic rocks to basin analysis was not easy and Snorre always served with the guidance, help and tutoring. Huge acknowledgments go to Alvar Braathen, who has introduced me to the outcrops of Billefjorden and Edgeøya, and always offered great support and advice. William Helland Hansen and Jan Inge Faleide are acknowledged for their supervision on the project. I strongly appreciate the scientific freedom and multiple possibilities for development and collaboration I had during the research.

The Late Triassic outcrops on southern Edgeøya, East Svalbard, allow a multiscale study of syn-sedimentary listric growth faults located in the prodelta region of a regional prograding system. At least three hierarchical orders of growth faults have been recognized, each showing different deformation mechanisms, styles and stratigraphic locations of the associated detachment interval. The faults, characterized by mutually influencing deformation envelopes over space-time, generally show SW-to SE-dipping directions, indicating a counter-regional trend with respect to the inferred W-NW directed progradation of the associated delta system. The down-dip movement is accommodated by polyphase deformation, with the different fault architectural elements recording a time-dependent transition from fluidal-hydroplastic to ductile-brittle deformation, which is also conceptually scale-dependent, from the smaller-(3rd order) to the larger-scale (1st order) end-member faults respectively. A shift from distributed strain to strain localization towards the fault cores is observed at the meso to microscale (<1 mm), and in the variation in petrophysical parameters of the litho-structural facies across and along the fault envelope, with bulk porosity, density, pore size and microcrack intensity varying accordingly to deformation and reworking intensity of inherited structural fabrics. The second-and third-order listric fault nucleation points appear to be located above blind fault tip-related monoclines involving cemented organic shales. Close to planar, through-going, first-order faults cut across this boundary, eventually connecting with other favourable lower-hierarchy fault to create seismic-scale fault zones similar to those imaged in the nearby offshore areas. The inferred large-scale driving mechanisms for the first-order faults are related to the combined effect of tectonic reactivation of deeper Palaeozoic structures in a far field stress regime due to the Uralide orogeny, and differential compaction associated with increased sand sedimentary input in a fine-grained, water-saturated, low-accommodation, prodeltaic depositional environment. In synergy to this large-scale picture, small-scale causative factors favouring second-and third-order faulting seem to be related to mechanicalrheological instabilities related to localized shallow diagenesis and liquidization fronts.--

The beginning of the Norwegian oil industry is often attributed to the first exploration drilling in the North Sea in 1966, the first discovery in 1967 and the discovery of the supergiant Ekofisk field in 1969. However, petroleum exploration already started onshore Svalbard in 1960 with three mapping groups from Caltex and exploration efforts by the Dutch company Bataaffse (Shell) and the Norwegian private company Norsk Polar Navigasjon AS (NPN). NPN was the first company to spud a well at Kvadehuken near Ny-Ålesund in 1961. This drilling marked the start of an exciting period of petroleum exploration in Svalbard, with eighteen exploration wells drilled in the period from 1961 to 1994. The deepest well so far, Caltex's Ishøgda-I near Van Mijenfjorden, reached 3304 m in 1966. NPN was involved in nine of the eighteen wells. The remaining wells were drilled by American (Caltex/Amoseas), Belgian (Fina), French (Total), Soviet/Russian (Trust Arktikugol), Swedish (Polargas Prospektering) and Norwegian companies Norsk Hydro and Store Norske Spitsbergen Kulkompani. None of the wells resulted in commercial discoveries, though several wells encountered gas in measureable quantities. Only the two wells drilled in the early 1990s were drilled on structures defined using a sparse 2D seismic grid, while the other wells were drilled based on geological mapping at the surface. Furthermore, more recent research and coal exploration boreholes have confirmed moveable hydrocarbons in close proximity to the Longyearbyen and Pyramiden settlements. In this contribution, we present a historical and brief geological overview of the petroleum exploration wells onshore Svalbard. We illustrate that the eighteen petroleum exploration wells have together penetrated over 29 km of stratigraphy, with the Late Palaeozoic-Mesozoic successions particularly well covered. Coal exploration and research boreholes primarily focus on the Mesozoic-Cenozoic successions. As such, the boreholes represent an important window to decipher the stratigraphic evolution of both Svalbard and the greater Barents Shelf.

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