Definition of gyttja in US English:

gyttja

noun

Geology
  • Sediment rich in organic matter deposited at the bottom of a eutrophic lake.

    • ‘Incorporation of old carbon into basal gyttja yields ages from bulk samples that are initially about 600 yr too old.’
    • ‘The organic-rich bottom deposits (sapropels or gyttja) are rich in oil-producing organic compounds.’
    • ‘The drift gyttja layer in Kalvöviken is synchronous with a short temperature anomaly found in ice cores from Greenland.’
    • ‘All laboratory tests were performed on 19 samples of gyttja and lacustrine chalk taken from the lakelands.’
    • ‘Radiocarbon determinations from this type of environment must be analysed with care because of the variable sources of carbon available to the plants which form the gyttja.’

Origin

Late 19th century: Swedish, literally ‘mud, ooze’.

Pronunciation

gyttja

/ˈyiˌCHä/