Fig. 3: Profile (left) formed of three thin sections through Layers 21–18, and photomicrographs (right) of sediment details.

A Layer 21, yellow silts with occasional crushed shell (probably land snail, Camaenidae) and infilled void spaces (v) with dark silts (red arrows) indicating minor vertical translocation of occupation material from Layer 20; B Layer 21, crushed shells (red arrows) showing natural accumulation of molluscs and deposition of coarse pre-occupation colluvium; C, D Layer 21/20 interface, with dark, organic sediment and anthropogenic inclusions. Horizontally aligned chert debitage fragment (red arrow) on lower boundary of Layer 20 and coarse shell fragments (blue arrows), bone (green arrow), and rock fragments deposited on trampled surface. In cross polars. D Layer 21 is calcareous prior to deposition of organic-rich Layer 20. Haphazard orientation of Layer 21 shell fragments (red arrows) are consistent with colluviation; E Layer 20, detail of chert debitage (ch) in cross polars. Sharp bone fragment (b) in a better preservation state than weathered bone from Layer 21. Sediment staining (Fe) is also evident, and a probable seed pod in lower part of image; F Layer 20. Charcoal (cc) and ash (micritic calcium carbonate) are preserved, often with plant cellular structure intact. A large rounded soil aggregate (sa) suggests reworking from outside shelter; G Localised concentration of ash (red arrow), sometimes partially dissolved; H Layer 20: well-preserved charcoal (blue arrows) and bone fragments (red arrows). Internal structure preservation suggests limited movement; I Displaced combustion feature fragment with laminated plant structures (red arrows) variably burnt with charcoal on what would have been the top (blue arrow); J Layer 19 sediment matrix, becoming increasingly organic-rich with finely divided charcoal powder and a darker colouration. Phytoliths at lower right (red arrow); K Layer 19, bone (b), tooth (t), and shell (s) fragments; L Layer 19, dense organic clays towards upper interface with Layer 18. Increase in coarse inclusions, including speleothem (sp) and limestone (l) fragments; M Gypsum crystals (g) infilling a void space; Layer 19/18 interface, showing abrupt transition from organic clays (Layer 19; N) to calcareous sediments (Layer 18; O).