*4.4. Implications for Basin Modeling*

Repeated ice loading during the Quaternary could have significant impact on sedimentary basins and add a degree of di fficulty to petroleum exploration. The isostatic e ffects of ice sheets, (in addition to possible glacial erosion/deposition) could give significant tilting of sedimentary basins in the peripheral areas of former glaciated area. The tilting of the reservoirs at the Norwegian Continental Shelf could be up to almost 3 m/km and could alter hydrocarbon migration pathways. The ice sheets will act as seesaw during glacial/interglacial period, while the isostatic response of erosion and sedimentation will grow iteratively during the glaciations, depending on the stability of the depocenters.

Di fferential vertical movement of the lithosphere related to glacial isostasy leads to repeated tilting of sedimentary formations and potential petroleum reservoirs therein, which may have greatly affected hydrocarbon migration pathways in the former glaciated area [3]. In addition, the upward and downward bending of the lithosphere lead to flexural stresses likely to a ffect faults and their permeability, which could add to changes in hydrocarbon migration pathways. The flexural stresses are adding to background stresses in the area.

The map of the flexural e ffect based on glacial isostasy shows that the SW Barents Sea is a ffected by flexural stresses due to the last ice age. Stress models sugges<sup>t</sup> that this e ffect may have caused high magnitude stresses to accumulate and therefore lead to an increased fracture-related permeability and escape of hydrocarbons in certain areas.

Most of the production licenses on the Norwegian Continental Shelf are located inside the former Last Glacial Maximum ice sheet (Figure 1). The results of our study demonstrate the importance of including the e ffect of glaciations in basin modeling studies of areas of petroleum potential. Adding to this are the temperature e ffects of glaciations and the e ffects of glacial erosion on temperature and stress discussed in more detail in [3].

**Author Contributions:** Conceptualization, I.F.L., W.F.; methodology, I.F.L., W.F., M.S.; software, I.F.L., W.F.; investigation, I.F.L., W.F., M.S.; writing—original draft preparation, I.F.L., W.F.; writing—review and editing, I.F.L., W.F.; M.S.; project administration, I.F.L.

**Funding:** Part of this study was supported through project no. 200657 "Neogene Uplift of the Barents Sea" by Norwegian Research Council and the oil companies ConocoPhillips, Det Norske, E.ON E&P, GDF Suez E&P Norge AS, NORECO, OMV (Norge), Statoil, Total E&P and Wintershall.

**Acknowledgments:** The authors would like to thank four anonymous reviewers for constructive and fruitful feedback, which improved the paper.

**Conflicts of Interest:** The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.
