Dverghamrar

The Dverghamrar (Dwarf Rocks) are beautifully formed columnar basalt rock formations, just east of the town of Kirkjubæjarklaustur. The rocks are mostly covered by vegetation, but you can walk down through a small opening in the rocks and as you walk down the basalt columns are revealed.

A sharp boundary is in the rock face, making it look like two layers, but the rocks were formed by the same lava. The upper layer is cube jointed basalt, formed due to irregular cooling caused by water, most likely meltwater from a glacier on top of the eruption vent during the eruption, while the columnar rocks were formed in the part of the lava that was not affected by the water.

Basalt columns are formed because of contraction in cooling basaltic melt, so that the rock shrinks and splits into pillars that are often hexagonal but can be three- to twelve-sided. The columns are always perpendicular to the cooling surface, i.e., point in the direction from which the cooling comes, and are therefore vertical in this case.

The area of Dverghamrar has been heavily eroded by both glaciers and waves, which has removed the once overlying strata, but younger and beautiful palagonite tuff formations can be seen in Mt. Fossnúpur just north of Dverghamrar.