Jericho is still the site par excellence for the definition of the early Neolithic.

The radiocarbon dates for the Natufian at Jericho extend back before the Younger Dryas, 11170-10980 BC, but the earliest set of calibrated dates starts only around 9300 BC (= sum Stage IV, Trench F I). Only the GL-dates (69, 70, 72) date into the hiatus; but as their deviations are very high, and they were questioned due to methodological problems, these dates have been disregarded. Two samples (BM 105 and BM 110) that date into the Younger Dryas come from stratigraphicly much younger layers. ^[1]

An analysis of the dates of the early Neolithic layers demonstrates that the radiocarbon dates are approximately consistent with the stratigraphy (Gopher 1994:226-228). In two cases where dating by both Pennsylvania and the British Museum exist, the Pennsylvania dates are a little older. The date of Pennsylvania (P387) for Trench FI, IV A overlaps only with the older date of the British Museum (BM 1327) in the 1-σ range between 9130 BC and 8920 BC. This correlates very well with the Pennsylvania date (P377: 9150-8810 BC) of Trench E I, II, V, Stage IV.

The material of the Pennsylvania sample of Layer DI VIA perhaps comes from the layer beneath, as it would fit quite well into this earlier time range.

The sums of dates of the trenches F and DI/II indicate for Stage VI/VIA a time range between 9150-9000 BC (11.6%); 8950-8450 (56.6%) BC, and for Stage VIIIA 8620 BC to 8320 BC. Stage VI/VI A would therefore be contemporary with the late PPNA or the phase de transition defined by Abbès and Stordeur between PPNA and PPNB and dated at Jerf el Ahmar between 8800-8610 BC, whereas Stage VIIIA would be contemporary with the early PPNB of the Northern Levant. This chronological determination is not compatible with the separation of PPNA and PPNB as defined by Kenyon (1981), who distinguished the phases on the basis of architectural criteria: she attributed layers with round building structures to the PPNA, but layers with rectangular buildings to the PPNB.

Consequently most of the skull burials must be dated to the middle or late PPNB (Benz in press). There are some exceptions. The skull burials of Trench M are stratigraphicly older. Similarly, the skull burials of Trench E could be older than the early PPNB because they were attributed by Kenyon to Stage VII/VIII and are thus older than the radiocarbon dated Stage VIIIA.

One of the major problems of Jericho is discerning differences between the middle and late PPNB. Kenyon, as was mentioned above, distinguished PPNA and PPNB mostly on the basis of the architecture; but she did not separate the middle from the late PPNB.

The radiocarbon dates for the late non-ceramic layers are contradictory (Fig.1). Especially problematic are the samples from Trench F. Neither the GL-dates (green), because they date one and the same sample, nor the Groningen dates (orange), which seem to be too old, are reliable. However, it is striking that the original dates of Groningen were the same as that of the British Museum (Burleigh 1981). These younger dates match the stratigraphy much better than the old dates and correlate very well with the radiocarbon dates of the other trenches. Stages XIV and XV of trench D I, which correspond stratigraphicly with the stages of Trench FI, are dated by samples BM 1793 and P 380 to a time range between 7880/7720-7570 BC. These dates give a terminus post quem for Stage XVII of Trench FI/DI.

It is thus possible to separate at least two chronological phases, of which the younger one may be divided in two sub-phases. The earliest PPN-dates are of Stage IV/IVA. Their sum ranges between 9300 BC and 8700 BC. This corresponds to Stages IVA (Trench D/F) and IV (Trench E I,II,V). The second group of dates centres between 9150 BC and 8450 BC corresponding to Stages VI/VIA (Trench D/F) and Stage VI (Trench E). Stage VIIIA would give the latest date of this phase, which dates between 8620 BC and 8320 BC. The only date ending a little later than 8320 BC comes from Stage IX (Trench F); but compared to other dates of Trench E and the stratigraphy, this sample may have been dislocated from an earlier layer.

Stage VIIIB ends with a thick burnt layer (Keynon 1981:48-49), but it is not possible to determine how quickly the site was resettled. There are two dates starting around 8250 BC; but the stratigraphy suggests they are too old.^[2]

The focus of the younger dates of the 8th millenium BC starts around 7950 BC and lasts until 7530 BC, although many of the calibrated ranges end earlier at about 7580 +/- 10 BC. This date correlates well, as would be expected, with a steep decline of the calibration curve between 7610 and 7580 BC. However, the stratigraphy indicates that the occupation of the site continued. The comparison of the radiocarbon dates with the stratigraphy also demonstrates that the dates P 382 and P 1789 are too old compared to their stratigraphic position.

Due to the few radiocarbon dates, only rough trends can be discerned. As a working hypothesis it can be suggested that there was a hiatus between Stage VIIIA and Stage VIIIC/IX and/or X. Weninger et al. (2009) recently suggested climatic causes for this abandonment of the site. ^[3]

The next occupational phase can be paralleled most probably with the late-middle or early-late PPNB.
In attempting any final interpretation, it should be kept in mind that the uppermost and the deepest PPN-layers of Jericho do not have radiocarbon dates. This is also true of Beidha, where the late PPNB phases have not been dated. The termination of the dates at about 7580 +/-10 BC therefore should not be interpreted as the end of the occupation of the site.