Icles, rounded to angular.Dominant grey rounded particles, frequent subhedral augite, few to frequent medium sandsize biotite laminae; rounded fragments of fine grey ash fall tuff and also other nevertheless unidentified lithics happen sparsely.Whitish micro to cryptocrystalline cement.Masao et al.eLife ;e..eLife.ofResearch articleGenomics and Evolutionary BiologyFigure .Laetoli Web page S Rebaudioside A Purity & Documentation geology.(A) Stratigraphic sketch of the sequence, as in testpit M.Numbers on the left correspond to the lithologic units observed inside the field modern soil; grey augiterich tuff; laminated grey tuff; finely layered grey and white tuff; light brown tuff.Unit two corresponds towards the Augite Biotite Tuff (Hay,); units and correspond respectively towards the upper and lower horizons from the Footprint Tuff (Hay,).Numbers around the right indicate the four and fourteen sublevels included, respectively, within the upper and decrease component (Hay,).Hominin tracks take place on the topmost sublevel of unit (red line); a related thick whitish footprintbearing level could be observed in the identical stratigraphic position at Localities and .Oblique hatch open cracks.White patches in unit are burrower tunnels and disturbances.Green rectangle location of panel B image.(B) Photomosaic showing the Footprint Tuff and part of the overlying unit..eLife.Masao et al.eLife ;e..eLife.ofResearch articleGenomics and Evolutionary BiologyTestpit M.Contemporary soil.Dark grey (,Y dark greydark greyish brown) clay loam to sandy clay loam, with welldeveloped medium to quite coarse subangular blocky structure, rather loose and moderately weak; sand is extra typical at the base, where PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/21495998 the structure is somewhat much less developed.Handful of FeMnoxide mottles.Thickness cm; abrupt undulating limit..Grey augiterich tuff.Greyish (.Y dark greygrey) silty sand, poorly sorted, with widespread coarse to quite coarse sandsize black rounded grains.Massive structure, powerful; no sedimentary structures.Thickness cm; sharp subhorizontal limit.Poorly sorted quite fine sand to coarse sandsize particles, like widespread anhedral to subhedral augite, grey rounded particles, greyishbrownish aggregates, other unidentified lithics..Laminated grey tuff.Finely interbedded light grey to brownish to black (.Y light brownish grey.Y light olive brownN black) sandy laminae and thin layers mm thick.Massive, very strong.Thickness cm; sharp limit marked by a thin planar void.Moderately wellsorted anhedral to subhedral, subrounded to subangular, medium to fine sandsize light grey to greenish grains; white microcrystalline cement.In the uppermost layers, the grainsize is slightly coarser (medium sand), and also the particles are subrounded to rounded; biotite laminae and brownish rounded aggregates are popular.The darker laminae usually consist of finer grains, as well as the cement is generally less abundant..Finely layered grey and white tuff.Only the leading surface was observed.Common animal tracks.Testpit TP.Modern soil.Dark grey (,Y dark greydark greyish brown) clay loam to sandy clay loam, with welldeveloped fine to very coarse subangular blocky structure, loose and moderately weak.Couple of FeMnoxide mottles.Thickness cm; abrupt undulating limit..Grey augiterich tuff.Greyish (.Y dark greygrey) silty sand, poorly sorted, with common coarse to quite coarse sandsize black rounded grains.Huge structure, powerful; no sedimentary structures.Thickness cm; sharp subhorizontal limit.Poorly sorted very fine sand to coarse sandsize particles, such as typical anhedral to subhedral augite,.