a: arrows point to one of several thin, orange pumice lapilli lenses typical of those found throughout the MV - 7 stratum containing the archaeological horizons; b: ventral side of a percussion flaked tool embedded in a 2 cm
thick tephra lens located on an uneroded, elevated surface between narrow drainage channels in stratum MV - 7, Unit 56 (see Fig 6b for a close - up of the dorsal side of the flake); c: typical micro-setting where thin orange lenses form during the summer months in shallow humid
grassy areas at Monte Verde.