Description
The model has an extent of 150×180 m and the displayed area is located in E Iceland. In the northern part, near the stream, there is a rectilinear, N10°-striking, 1-m-thick dyke made more prominent by erosion. The dyke can be followed as far as a point (to the south) where it crosscuts a NW-SE striking, mostly vertical inclined sheet, as thick as 0.65 m. Moving to the south, on the other side of the road (trail), another dyke can be spotted, with a different strike from the previous one (NE-SW trending) and as thick as 1 m. This second dyke terminates in correspondence of a larger outcrop, made of a succession of gently inclined sills, stacked atop each other, and forming a half-flower intrusive structure (Tibaldi and Pasquaré 2008). The sills are affected by widespread columnar jointing. Based on the geometry of the columnar joints and on the discontinuities that separate each single sills (columns are perpendicular to the basal and upper surface of an originally planar intrusion), it is possibile to infer an inclination of the sills of about 10°; the succession of sills was originally horizontal, and was tilted later on by tectonic processes. Further details on dykes and geology in eastern Iceland are in Walker (1974), Gudmundsson (1983), Jóhannesson and Sæmundsson (1998) and Gudmundsson et al (2014).

Credits: UAV survey and 3D DOM is provided by Bonali F.L., Russo E and Pasquaré Mariotto F., funding are from MIUR project ACPR15T4_00098 (http://argo3d.unimib.it/). Description provided by Alessandro Tibaldi.

References

  • Gudmundsson, A. (1983). Form and dimensions of dykes in eastern Iceland. Tectonophysics, 95(3-4), 295-307.
  • Gudmundsson, A., Pasquarè, F. A., & 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.
  • Tibaldi A., ,Pasquaré F. (2008). A new mode of inner volcano growth: the “flower intrusive structure”. Earth and Planetary Science Letters, 271, 202-208.
  • Walker, G. P. (1974). The structure of eastern Iceland. In Geodynamics of Iceland and the North Atlantic area (pp. 177-188). Springer, Dordrecht.