Cross-cutting relationships among sills and dykes, East Iceland

Description
The model covers an about 100x80m-wide area; the cliff is composed of a succession of horizontal, Tertiary basaltic lava flows, intruded by five, 1.5-m-thick vertical dykes striking about NE-SW, as well as by a horizontal, 1.3 m-thick sill, which is parallel to the lava flows. Zooming in, in correspondence of the cross-cutting contact between the sill and the dykes, it is possible to notice that the sill interrupts the continuity of the dykes. This clearly suggests that the former is more recent than the dyke intrusions. The area is located in eastern Iceland, whitin Tertiary age lava units. Further details on the dykes and geology in eastern Iceland are in Walker (1974), Gudmundsson (1983), Jóhannesson and Sæmundsson (1998) and Gudmundsson et al (2014).

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

References

• Gudmundsson, A. (1983). Form and dimensions of dykes in eastern Iceland. Tectonophysics, 95 (3-4), 295-307.
• Gudmundsson, A., Pasquarè, F., Tibaldi, A. (2014). Dykes, sills, laccoliths, and inclined sheets in Iceland. In Physical Geology of Shallow Magmatic Systems (pp. 363-376). Springer.
• Jóhannesson, H., & Sæmundsson, K. (1998). Geological map of Iceland, 1: 500,000. Bedrock Geology. Natturufraedistofnun Islands, Reykjavik.
• Walker, G. P. (1974). The structure of eastern Iceland. In Geodynamics of Iceland and the North Atlantic area (pp. 177-188). Springer, Dordrecht.