Relevant Research
Gudmundsson, A. (1992). Formation and growth of normal faults at the divergent plate boundary
in Iceland. Terra Nova, 4, 464–471.
The divergent plate boundary intersects Iceland and is characterized by a 40-80 km long and 5-10 km wide tension fractures and faults. The lava flow at the surface runs horizontal, but becomes tilted as you get deeper in the crust. At the surface of the rift zone the joints are vertical and parallel to the vertical principal stress. Because of tilting of the lava pile, the columnar joints become oblique to this stress, hence becoming potential shear fractures, and form echelon sets at greater depths in the crust. Theoretical considerations suggest that normal faults start to nucleate on sets of en echelon columnar joints and/or large-scale tension fractures at crustal depths of 0.5–1.5 km. The width (depth) must be the smallest (controlling) dimension of many faults. Nevertheless, there is a positive linear relation (r = 0.91) between maximum throw and length of the Holocene faults. If the faults grow as self-similar structures, the throw-length relationship can be explained by a similar relation between fault length and width.
Maclennan, J., M. Jull, D. McKenzie, L. Slater, and K. Grönvold (2002). The link between
volcanism and deglaciation in Iceland, Geochem. Geophys. Geosyst., 3-40.
Deglaciation is examined and compared to the eruption rate and lava composition in temporal variations of Iceland's history. Average eruption rates at the end of the last glacial period were 100 times higher than those from the actual glaciation period, and recent times. Geochemical data extracted from basalt samples of two volcanic systems show a temporal variation in both the major and trace element composition of the eruptions. If the increase in eruption rates reflects increased melt production rates in the mantle, then the relative timing of deglaciation and the burst in eruption rates can be used to estimate the rate of melt transport in the mantle. The observed duration of enhanced eruption rates after deglaciation can be reproduced if the vertical melt extraction velocity is >50 m yr−1.
Geirsdottir A., Miller G.H., Andrews J.T. (2007). Glaciation, erosion, and landscape evolution of
Iceland, Journal of Geodynamics, 43, pp. 170-186.
Studies in stratigraphic and sediment have indicated that Iceland has experienced over twenty glaciations during the last four to five million years. The pattern of glacial erosion was to a large part controlled by constructive volcanic processes resulting in increased topographic relief after two and a half million years. New studies are presented that define the rates of landscape denudation during the major part of the Holocene (the last 10,200 years): one based on the Iceland shelf sediment record, the other from the sediment record in the glacier-fed lake, Hvítárvatn. Both studies indicate average Holocene erosion rates of about 5 cm ka−1 similar to our erosion rate estimate for four to five million year old strata that has not been subjected to regional glaciation.