Dip-slip fault, Theystareykir Fissure Swarm, Northern Iceland

Description
This 3D encompasses an area of about 95 x 70 m and shows the geometry of a recent, N10°-striking, active dip–slip fault with a steeply-dipping fault plane and a 10-m offset; the fault, situated in the Theistareykir Fissure swarm of Northern Iceland, separates two horizontal surfaces – the top of the footwall and the hanging wall, respectively. Intense fracturing is also present: the topographic surface of the subsided hanging wall contains sets of fractures with varying directions, formed during the emplacement and cooling of the lava flow. The following tectonic deformation due to faulting has subsequently caused an increase in opening of the primary fractures. The age of the fractured lava flow is 14.5 ka BP (Saemundsson et al., 2012). Moreover, in the area is it possible to notice several, typically periglacial features, known as ‘pingo’, formed in response to the growth of ice lenses within the soil.

Credits: UAV-based survey and 3D DOM by Fabio L. Bonali; funding is from MIUR project ACPR15T4_00098 (http://argo3d.unimib.it/). Model descripition by Alessandro Tibaldi and Federico Pasquaré Mariotto.

References

• Pasquaré Mariotto F., Bonali, F. L., & Venturini, C. (2020). Iceland, an Open-Air Museum for Geoheritage and Earth Science Communication Purposes. Resources, 9(2), 14.
• Saemundsson, K., Hjartarson, A., Kaldal, I., Sigurgeirsson, M.A., Kristinsson, S.G. and Vikingsson, S. (2012) Geological map of the Northern Volcanic Zone, Iceland. Northern Part 1: 100.000. Reykjavik: Iceland GeoSurvey and Landsvirkjun.