Diatomite deposit in the basin of Lake Soijärvi, central Finland

T. Grönlund
1986 Bulletin of the Geological Society of Finland  
GRÖNLUND, TUULIKKI, 1986: Diatomite deposit in the basin of Lake Soijärvi, central Finland. Bull. Geol. Soc. Finland 58, part 2,[35][36][37][38][39][40][41][42][43][44][45] Diatomite and underlying diatomaceous gyttja are met with in the overgrown Soijärvi basin at Karttula. Diatomite is considered a material containing abundant diatoms and with a Si0 2 content of 60 %; diatomaceous gyttja has a Si0 2 content of 20-60 The diatom stratigraphy of the Soijärvi sequence was studied. The diatomite
more » ... ed. The diatomite and the diatomaceous gyttja are dominated by the comparatively small Centrales diatoms, mainly Melosira distans and variations. The diatom flora encountered was on the whole very broken. The chemical composition, porosity and melting temperature were determined on diatomite in a natural state. Porosity was also determined after ingnition at 700°C. The distribution in particle size was determined on diatomite treated with hydrogen peroxide. The specific surface area of the diatomite in a natural state is 20,100 m Vkg and, when ignited, 28,800 m 2 /kg.
doi:10.17741/bgsf/58.2.004 fatcat:sk6tlkn4avg2vdlijemvdopslm