## 2 Notes on the Theory, Method and Data
### Data: Remote Sensing and Terrestrial
#### 2.4.4 Archaeological Data
The Holocene archaeological sequence for this region consists of seven cultural units grouped into four main periods: Early (\(\sim\)9500-7300 bp), Middle (\(\sim\)7100-6600 bp), Late (\(\sim\)6500-5800 bp) and Final Neolithic (\(\sim\)5700-4500 bp) (\"bp\" refers to uncalibrated age as given in primary research publications (in particular, [29])), followed by a brief Late Holocene occupation during a short moist period \(\sim\)3860 bp. The local Holocene climatic optimum coincides with the latter part of the Early Neolithic (\(\sim\)8050-7300 bp; [29]). This depression constitutes the primary area for the testing of our hypothesis as it offers data suitable for a controlled discussion. The northern part of our research area contains the Kharga Oasis, a large and narrow depression (220 km in length, 15-40 km in width) that runs north to south ca. 200 km west of the Nile. Its northern and eastern borders are delimited by the scarps of the Egyptian Limestone Plateau at \(\sim\)350 m asl. The mean elevation of the depression itself is around 50 m asl [30; 31]. Several regional projects have brought to light here numerous Pleistocene and Holocene sites occurring in the context of spring vent pools, lakes, playas and wadis; an established spatial and temporal pattern in the regional record of prehistoric occupation; and nearly continuous occupation for at least the last 300,000 years thanks to the presence of stable sources of water from artesian springs (e.g., [31; 32; 33; 34; 35]). This multiplicity of sources of water and of archaeological data makes this oasis less suitable for testing the hypothesis. For this reason, the Kharga Oasis is further considered a secondary area where more general correlation with the data from the south is required. For the purposes of correlation, we also refer to the evidence of robust Lower and Middle Paleolithic occupations at lakeshores and at spring vents and of the ephemeral Holocene human presence at Bir Tarfawi and Bir Sahara, two small deflational basins situated ca. 100 km west of the Kiseiba Scarp [27; 36]. The archaeological sites from the Toshka-Kiseiba depression selected for this study are overviewed in Table 1. Most of them correspond to areas with clusters of localities occupied during more than one phase or period of prehistory. Only evidence found in situ is included for both the Pleistocene (1 area) and Holocene (11 areas). To indicate the dating of the Holocene remains, we employ a simplified sequence of two main periods, with one corresponding to the \"reoccupation\" (\(\sim\)10,500-9000 BP) and \"formation\" (\(\sim\)9000-7300 BP) phases of [24] (their figure 3b,c) and the Early and Middle Neolithic of the regional archaeological sequence, and the other to the \"regionalization\" phase (\(\sim\)7300-5500 BP) of [24] (their figure 3d) and the Late and Final Neolithic in this region. To plot the positions of the areas onto the maps presented in this study, the topographic and cartographic data available in primary publications (see Table 1) were used to identify the locations on Google Earth. The coordinates included in the table refer to the plays, i.e., often the lowest-lying sectors of the basins. Where elevation (height above present sea level, asl) of the locations was not indicated in the publications, it was estimated using Google Earth and is expressed as an average of elevations of the playa and its shores where human settlements were usually located.