*Article* **Tilting and Flexural Stresses in Basins Due to Glaciations—An Example from the Barents Sea**

### **Ingrid F. Løtveit \*, Willy Fjeldskaar and Magnhild Sydnes**

Tectonor AS, P.O. Box 8034, N-4068 Stavanger, Norway; wf@tectonor.com (W.F.); ms@tectonor.com (M.S.) **\*** Correspondence: ifl@tectonor.com

Received: 21 September 2019; Accepted: 7 November 2019; Published: 11 November 2019

**Abstract:** Many of the Earth's sedimentary basins are a ffected by glaciations. Repeated glaciations over millions of years may have had a significant e ffect on the physical conditions in sedimentary basins and on basin structuring. This paper presents some of the major e ffects that ice sheets might have on sedimentary basins, and includes examples of quantifications of their significance. Among the most important e ffects are movements of the solid Earth caused by glacial loading and unloading, and the related flexural stresses. The driving factor of these movements is isostasy. Most of the production licenses on the Norwegian Continental Shelf are located inside the margin of the former Last Glacial Maximum (LGM) ice sheet. Isostatic modeling shows that sedimentary basins near the former ice margin can be tilted as much as 3 m/km which might significantly alter pathways of hydrocarbon migration. In an example from the SW Barents Sea we show that flexural stresses related to the isostatic uplift after LGM deglaciation can produce stress changes large enough to result in increased fracture-related permeability in the sedimentary basin, and lead to potential spillage of hydrocarbons out of potential reservoirs. The results demonstrate that future basin modeling should consider including the loading e ffect of glaciations when dealing with petroleum potential in former glaciated areas.

**Keywords:** Glaciations; isostasy; flexural stress; faults; hydrocarbon migration
