Environmental changes in Sauðlauksdalur, N-W Iceland: evidence from sedimentary- and historical data

• Main Author: Jóhannes Marteinn Jóhannesson 1983-
• Other Authors: Háskóli Íslands
• Format: Thesis
• Language: English
• Published: 2014
• Subjects: Jarðfræði; Sauðlauksdalur; Veðrun; Jarðlög; Vestfirðir; Sandspit; Iceland
• Online Access: http://hdl.handle.net/1946/17117

Sauðlauksdalur is a valley located in Vestfirðir in N-W of Iceland. There has been an on going aeolian transport of sand into the valley for the last centuries, and it has formed a large sand field in the middle of the valley and a sandspit at the beachfront. The farmland in the valley has been badly damaged by this sand and the battle against it has been well documented throughout the centuries. The transport of sand into the valley has decreased since AD 1920, a decreased that can be traced to both climate changes after the end of the Little Ice Age and efforts by Soil Conservation Service of Iceland to increase vegitation on the sand field and the beach. Eight sections were dug, and two of them contained both soil and sand layers. Section 48 was chosen for study due to its location in the valley and multiple soil layers. In all there were fifteen different layers in the section, 4 soil layers, 8 sand layers, 2 soil and sand layers and one clay and gravel layer. Four layers were chosen for radiocarbon dating and all the sand layers, including two from section 52, were sieved. All the sand samples were medium grained sand and originated from dunes at the beach and inland. The sand is yellow in colour and consist of both seashell- and basalt rock fragments. The sand deposits are layered at the front of the valley, but no layering was visual in the sand layers of section 48. The radiocarbon dating of the soil layers failed, but it is likely that one of the soil layers was formed during the Medieval Warm Period. The aeolian transport of sand therefore began before the onset of the Little Ice Age, but reached its maximum during that period. It is likely that climate change during the Little Ice Age had an effect that increased the amount of aeolian transport of sand into the valley.