Orsa, Sweden thousands of visitors and the inhabitants of Orsa. The big forests start just north of the town of Orsa, with the sparsely populated Orsa finnmark, to which many Finns emigrated during the 17th century. About 500 people speak the Orsamål dialect, an Old Scandinavian language, which is a variant of Dalecarlian, also called Old Swedish in Minnesota, USA. Orsa is twinned with: Orsa, Sweden Orsa is a locality and the seat of Orsa Municipality, Dalarna County, Sweden, with 5,308 inhabitants (2010). It is located in the northern part of lake Siljan, about north of the town Mora. Inlandsbanan and European
Siljan Ring by rocks of the Llandovery series (Lower Silurian). During the last ice age the area was covered by a thick icesheet. The bedrock was sculpted by the ice, with the softer Palaeozoic sedimentary rocks being preferentially eroded. These erosional hollows are now occupied by lakes Siljan, Orsa, Skattungen and Ore. In accordance with theories about abiogenic petroleum (that hydrocarbons can be formed without involving material from dead plants and animals), astrophysicist Thomas Gold suggested that there might be major deposits of oil and natural gas in the area. Drilling was carried out in the late 1980s and early 1990s but