Stability of phytoliths in the archaeological record: a dissolution study of modern and fossil phytoliths

The FLK Zinj paleolandscape: Reconstruction of a 1.84 Ma wooded habitat in the FLK Zinj-AMK-PTK-DS archaeological complex, Middle Bed I (Olduvai Gorge, Tanzania)

“…At alkaline pH, phytoliths have high rates of dissolution (Fraysse et al, 2006). Morphotype three-dimensional shape and surface decoration could therefore be lost (Cabanes et al, 2011;Cabanes and ShahackGross, 2015). Taphonomical processes, however, affect phytolith morphotypes differently, such as certain morphologies are more stable than others.…”

“…Taphonomical processes, however, affect phytolith morphotypes differently, such as certain morphologies are more stable than others. For example, globular granulate are better preserved than grass silica short cells in the sense that they retain enough of their morphological shape to be recognized as globular bodies, while grass silica short cells such as bilobate are likely to considered "unidentifiable" after dissolution has started to modify the 3D shape (Cabanes et al, 2011). Despite this, the conservation of some GSSC phytoliths and, above all, the preservation of hexagonal platelets (hat-shaped) phytoliths of Cyperaceae (sedges), rarely preserved even in surface soil samples (Novello et al, 2012), suggest that paleovegetation patterns, rather than partial dissolution of phytoliths due to taphonomical processes, are responsible for the phytolith assemblages obtained here.…”

The 9th century BCE destruction layer at Tell es-Safi/Gath, Israel: integrating macro- and microarchaeology

“…Cabanes et al (2011) showed in an in vitro experiment that the inflorescence phytoliths of wheat are less stable than the phytoliths of leaves and stems. This can result in better preservation of leaf and stem phytoliths.…”

“…This can result in better preservation of leaf and stem phytoliths. Cabanes et al (2011) and Carnelli et al (2002) also showed that the so-called "weathered" phytoliths are actually present in the plant itself, and that this widely used parameter for assessing preservation may not be reliable. Cabanes et al (2011) also showed that phytolith morphotypes more prone to dissolution and abrasion are the delicate ones such as hairs, papillae and thin decorated long cells.…”

“…Cabanes et al (2011) and Carnelli et al (2002) also showed that the so-called "weathered" phytoliths are actually present in the plant itself, and that this widely used parameter for assessing preservation may not be reliable. Cabanes et al (2011) also showed that phytolith morphotypes more prone to dissolution and abrasion are the delicate ones such as hairs, papillae and thin decorated long cells. The phytoliths from the whole area under study contained relatively high amounts of the more delicate inflorescence phytoliths of cereals, and the overall proportion of weathered phytoliths was low (Table 1 supplementary material).…”