Holocene paleohydrology of Viiankiaapa mire, Sodankylä, Finnish Lapland

• Main Author: Suonperä, Enni
• Other Authors: Helsingin yliopisto, Matemaattis-luonnontieteellinen tiedekunta, Geotieteiden ja maantieteen laitos, University of Helsinki, Faculty of Science, Department of Geosciences and Geography, Helsingfors universitet, Matematisk-naturvetenskapliga fakulteten, Institutionen för geovetenskaper och geografi
• Format: Master Thesis
• Language: English
• Published: Helsingfors universitet 2016
• Subjects: Geology; Geologia; Geologi; Kitinen; Sodankylä; Lapland
• Online Access: http://hdl.handle.net/10138/161265

In 2011 AA Sakatti Mining Oy published a promising ore discovery in Sodankylä, Finnish Lapland. The need for more knowledge led to the start of Sakatti geoenvironments -project in collaboration with the University of Helsinki. As a part of this project, the Holocene paleohydrology of Viiankiaapa mire was reconstructed. Viiankiaapa mire is located on the eastern side of Kitinen River and has developed in close connection to it. It is a large aapamire complex consisting of multiple smaller minerotrophic mire sites and bogs. Viiankiaapa conservation area was first established in 1988. A large portion of Viiankiaapa is now part of the Natura 2000 conservation network. To study the development and paleohydrology of Viiankiaapa mire, a 4.3 meter peat core (VA310315, 7497803 N/0490511 E) was collected using a Russian peat sampler. From the peat core, six specimens from increasing depth levels were sampled for age determinations to establish reliable chronology. Dating was conducted at LUOMUS Laboratory of chronology at the University of Helsinki, using 14C AMS dating method. Peat stratigraphy was studied on site and humification determined using von Post method. Physical properties of the peat (LOI550 and water content) were determined in 2 cm resolution. The colour of the ash was determined using Munsell soil color chart. Same resolution was used in geochemical analyses of 17 individual elements (C, N, S, P, K, Ca, Mg, Na, Fe, Al, Cu, Ni, Zn, Ti, Mn, Pb, Si). C, N, and S contents were determined using gas chromatography, while all the other elements were analyzed using ICP-MS. From the element contents, multiple ratios were calculated in order to study the Holocene deposition pattern of individual elements. Element/Ti profiles show an increase in mineral material input in c. 8 000 – 6 000 cal. BP, c. 4 800 – 3 000 cal. BP, and 2 500 – 1 900 cal. BP, suggesting enhanced flooding of Kitinen and increased humidity. Early Holocene (11 700 – 8 200 cal. BP) is indicated as a period of higher detritic material input. ...