The Late Carboniferous – Early Permian Gipsdalen Group and the Early to Late Permian Templefjorden Group are known hydrocarbon plays in the Arctic region, e.g. on the Finnmark Platform, Loppa High and Sverdrup Basin. Time‐equivalent deposits crop out on the island of Spitsbergen and consist of mixed carbonate and non‐carbonate (primarily siliciclastic, siliceous, organic‐carbon rich and clayey) sediments deposited in continental to deep‐marine settings. In rock samples (n = 73) collected from five outcrop locations on Spitsbergen, thin‐section analysis showed the presence of ten microfacies types ranging from claystones and spiculitic cherts to rudstones and dolostones. Petrophysical and textural properties of the samples were measured to evaluate the link with the acoustic (P‐ and S‐wave) velocities of these generally tight rocks, which have an average porosity of about 2%. Variations in acoustic velocity measurements primarily depend on variations in mineralogical composition (silica versus carbonate) and, to a lesser extent, on variations in porosity and bulk density. Pore networks in the sediments are dominated by microporosity and (micro)cracks, followed by interparticle porosity. Recrystallization effects and pore shape variations show a lesser effect on the P‐wave velocity. Clay content does not exceed 12.7% and also has a secondary impact on the acoustic velocities. Defining which textural and physical parameters control the acoustic properties of these carbonate and non‐carbonate sedimentary rocks will help with the interpretation of the seismic response of equivalent deposits in the subsurface.

The non-unique correspondence between seismic and subsurface geology is a fundamental problem when interpreting seismic data sets. Synthetic seismic models of outcrop analogs are commonly constructed to cover the gap between the small-scale outcrop observations and low-resolution seismic data. The Permian biosiliceous carbonatecarbonate sediments on Spitsbergen are characterized by a wide variability in lithologies and microfacies determining the petrophysical properties (e.g., porosity, acoustic properties) that consequently complicate seismic interpretation. This study uses 1D and 2D synthetic seismic modelling techniques (at different resolutions) to gain an understanding of how seismic reflectors are expressed with respect to the sediment distribution, aiming to facilitate real seismic interpretation. In the study area, nine microfacies were defined that were used to produce a geological model displaying small-scale microfacies variations within a well-defined sequence stratigraphic framework. Laboratory derived petrophysical properties (Vp, ρBulk and AI) were assigned to each predefined microfacies body in the geological models in order to construct acoustic impedance models that were used to produce synthetic seismograms. The appearance of the seismic reflectors in the synthetic seismic profiles is primarily controlled by changes in mineral composition and link to spatial microfacies distributions within the depositional sequences. Differences in acoustic impedance and the origin of synthetic seismic reflections within a single microfacies type are mainly caused by porosity contrasts (varying between 5 and 20%) and diagenetic modifications such as chertification and cementation. This detailed information cannot be derived from the low-frequency seismograms (25-100 Hz) resulting in changes in seismic expression when seismic resolution diminishes. Comparison with time equivalent, real and synthetic seismic data of the Finnmark Platform reveals similarities with the synthetic seismic reflection patterns of Spitsbergen. In both areas, the pronounced seismic traces follow abrupt microfacies transitions, which are coherent with cycle boundaries and timelines.

Because of outstanding outcrops, Spitsbergen (Svalbard archipelago) provides unique opportunities to investigate the whole Upper Palaeozoic succession in great detail. This study can help to interpret the stratigraphic history and depositional evolution at other locations exposing coeval shelf strata along the northern margin of Pangea, e.g., the southern Barents Sea and Arctic Canada. Bed-scale outcrop observations are combined with microfacies studies to interpret the sedimentary settings and depositional environment of the Upper Palaeozoic strata. A sequencestratigraphic analysis has been carried out to evaluate the relative timing of sediment facies deposition in response to sea-level changes. The Early Artinskian to Kazanian successions of the Templet Member and the Kapp Starostin Formation were divided into five parasequences that are superimposed on a long-term, second-order, sea-level fall. These parasequences record a fundamental change of the sedimentary setting, from a restricted-marine, warm-water carbonate platform to an open-marine, cold-water, biosiliceous-carbonate ramp system. A cross-section across Svalbard comprising nine onshore sections shows that during deposition of the Kapp Starostin Formation a major depocentre marked by thick parasequences and a higher proportion of deep-water facies (bedded cherts) is located in the southwest of Spitsbergen (at Akseløya), whereas northeastern Svalbard records shallow-water microfacies. Svalbard was tectonically passive during the Permian; the local differences in accommodation space and facies were most likely linked to the rejuvenation of pre-existing structural elements, inherited from the Carboniferous. A deepening of the depositional environment combined with cold-water climatic conditions as recorded in our study area has also been documented in other Upper Palaeozoic successions around the Arctic, such as the Finnmark Platform (Norwegian Barents Sea) and the Sverdrup Basin (Arctic Canada). This transition in the depositional environment along the northern margin of Pangea is the result of large-scale changes in oceanic circulation patterns and local palaeogeographic changes during the northward movement of Pangea.