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Currently, the question of whether or not the presence of oil in sandstone inhibits quartz cementation and preserves porosity is still debated. Data from a number of Cambrian sandstone oil fi elds and dry fi elds have been studied to determine the effects of oil emplacement on quartz cementation. The data show that the porosity distribution is not affected by the presence of oil in sandstones from oil fi elds and dry fi elds with similar porosity distribution. From this, it can be concluded that oil emplacement does not lead to preservation of primary porosity, and silica supply for quartz cementation is derived from internal sources. Rather, in spite of large variation in porosity and quartz cement content, a regular pattern of porosity decrease is related to increasing temperature or depth. The observed heterogeneity is due to local factors that infl uence the precipitation of quartz cement, including sandstone architecture, i.e., distribution of shales within the sandstone bodies, and sandstone thickness. Heterogeneity is inherent to sandstone architecture and to the fact that silica for quartz cementation is derived from heterogeneously distributed local pressure solution. Models predicting reservoir properties should encompass facies and architecture as important independent factors.

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The article contains results obtained from realization of the Polish and Lithuanian Baltic case study within the EU -FP 7 SubCoast project, which one of the primary aims was analysis of vertical ground movements, potentially causing geohazards in the coastal areas. To reach this goal Interferometric Synthetic Aperture Radar (InSAR) data were obtained. For the Polish and Lithuanian Baltic coast ERS archive radar data were processed in order to provide Permanent Scatterer (PSInSAR, PSI) results that were then used to create the new innovative productDynamic DEM (DDEM). The deformation model defined by the SubCoast project normally needs to be created by merging InSAR, satellite navigation (GNSS), optical leveling and/or gravimetry measurements. Elaboration of DDEM enables more effective comparison between PS and tectonic features. Comparison of PS time series with groundwater changes shows a direct correlation, confirming impact of groundwater on subsidence or uplift of the ground surface. The results of the geological interpretation demonstrated that the examples of movements detected by PSI include subsidence linked to deformation of engineering constructions, compaction of organic or weak soils, and eolian accumulation or deflation processes of the sand dunes. For the Polish and Lithuanian coasts most of the area proved to be stable, nevertheless some local deviations up to -15 mm per year of movement were found.