Diatoms as indicators of provenance in Finnish sub-neolithic pottery

The occurrence and research potential of microfossils in inorganic archaeological materials

“…Clay mixing has been inferred by the discovery in single artifacts of microfossil specimens with conflicting geological ranges (Hunt, 1996) or environmental tolerances (Jansma, 1977;Matiskainen and Alhonen, 1984). The addition of solid particulate temper to clay pastes has been identified in a similar way.…”

“…This makes them an important environmental tool for the reconstruction of ancient and more recent water conditions in lakes and coastal sediments. The palaeoenvironmental potential of diatoms has been exploited in several provenance studies of ancient ceramics from northwest Europe (Foged, 1968;Edgren, 1970;Jansma, 1977Jansma, , 1981Jansma, , 1984Jansma, , 1990Alhonen and Väkeväinen, 1981;Gibson, 1983a, b;Matiskainen and Alhonen, 1984;Stilborg, 1997).…”

“…Microfossils have been used in several ways to investigate aspects of the paste preparation process of ceramics, including the mixing of different clays (Jansma, 1977;Matiskainen and Alhonen, 1984;Hunt, 1996;Stilborg, 1997;Quinn and Day, 2007) and the addition of temper (Gibson, 1983a;Jansma, 1981Jansma, , 1984Ayyad, Krzywinski, & Pierce, 1991). Clay mixing has been inferred by the discovery in single artifacts of microfossil specimens with conflicting geological ranges (Hunt, 1996) or environmental tolerances (Jansma, 1977;Matiskainen and Alhonen, 1984). The addition of solid particulate temper to clay pastes has been identified in a similar way.…”

Ceramic micropalaeontology: the analysis of microfossils in ancient ceramics

“…The salinity analysis of Quaternary diatom floras from ancient ceramics in northwest Europe has been used in a range of studies to interpret provenance in this way (Foged, 1968;Edgren, 1970;Jansma, 1977Jansma, , 1981Jansma, , 1984Jansma, , 1990Alhonen & Väkeväinen, 1981;Gibson, 1983;Matiskainen & Alhonen, 1984;Stilborg, 1997). On a simple level, several analyses have used the distinction between ceramics containing salinity tolerant (polyhalobous) diatoms that were produced from marine clays and those with salinity intolerant (oligohalobous) diatoms from freshwater environments, to distinguish between local and nonlocal ceramics at coastal sites in the Netherlands and Denmark (e.g.…”

“…The analysis of microfossils in archaeological ceramics has been used in several ways to decipher the nature of paste preparation. The presence in single sherds of microfossils of conflicting geological ages or environmental tolerances has been interpreted as evidence for both clay mixing (Jansma, 1977;Matiskainen & Alhonen, 1984;Hunt, 1996) or the addition of temper (Jansma, 1981(Jansma, , 1984. However, as highlighted by the micropalaeontological analysis of Punic artefacts from the island of Mozia (Quinn et al, 1998), mixed microfossil assemblages in ceramics can also result from the exploitation of river clays containing reworked material.…”