Three geological formations build the bedrock of the Nahal Karkom area. The base of the sequence consists of rare outcrops of greenish gray calcareous shale, with limonitic nodules and gypsum veins that belong to the TaqiyaFormation (Palaeocene). The MorFormation (Lower Eocene) overlies in conformity; it is made up of alterations biomicritic limestone and blackish brown chert layers (thickness 1– 10 cm). In places, the chert layers are included in well cemented, white grayish and partially silicified calcareous strata of chalk type. The NizzanaFormation (Lower Eocene) is set at the top of the sequence and covers almost completely the Har Karkom plateau. In general, it is composed of hard limestone and silicified limestone with a black patina. The upper layers of this formation are characterized by grayish black tabular chert nodules.
Looking at the geomorphological features of the site, it is set on an alluvial terrace deposited at the confluence of a small stream with the main valley of Nahal Karkom. At the HK/361 site, the raw material for the tool kit is made up of chert, mostly of the gray variety from the Nizzana Formation, although the brown chert from the Mor Formation is also present; sandstone artifacts are very scarce and the recovered milling implements are made of local limestone.
The site was discovered during a survey of the area by E. Anati (License No. G-53/1996), when abundant flint blades were found on the ground. The lithic industry, based on very thin laminar flints, consisted of many blades, small blades, bladelets, microliths and points. The implements showed either retouched or naturally sharp edges. Denticulate retouch, notches and blades with a sharp distal edge were found as well. Some of them had retouch or denticulate retouch on the distal edge. Even naviform cores, although not arrowheads, were found. The site was surveyed again (License No. G-10/2006), when a conspicuous number of flints were found on the surface, including the first Jericho points.
During April 2007, a trench (length 4.5 m, width 1 m, depth 0.15 m; Fig. 1: a) was dug in the southern portion of the northern section. The area was then extended to the east of the trench, cleaning a rectilinear surface (4×6 m, depth 0.1 m) and excavating 8 sq m. A small sounding was dug in the southern end of the trench (Pit 1; 0.5×0.5 m; depth 0.5 m; Fig. 1: b). The excavation extended farther east during the 2008 season and another sounding was cut in the southeastern corner of the area (Pit 2; depth 0.5 m; Fig. 1: c). The area was excavated to a depth of 0.1 m, the sediment was screened through a 5 mm mesh and all lithic material was collected for classification.
The stratigraphy of Pit 1 outlined a sequence of at least three alluvial deposits below the colluvial silts and one erosion event that followed the last two alluvial phases in the east–west section (Fig. 2a). The north-south section (Fig. 2b) displays five units: Unit 1 is thin silt layers with rare small chalky clasts; Unit 2 is dark sandy silt with pebbles; Unit 3 is grayish silt sand with rare pebbles; Unit 4 consists of gravel in sandy yellow matrix; and Unit 5 is alluvial deposit with angular to sub-rounded cobbles. The three alluvial deposits demonstrate less intense precipitation with time. Lithic material was mainly recovered from the upper colluvial sediments.
The stratigraphy of Pit 2 clearly showed that the Neolithic settlement lies above the alluvial events that had built the terrace. The stratigraphic section displays six units (Fig. 3): Units 1 and 3 are sandy silts and lithics; Unit 2 is sterile sandy silt; Unit 4 consists of alluvial deposits with big cobbles; Unit 5 is alluvial deposits with pebbles; and Unit 6 is alluvial deposits with cobbles. At the top of the intermediate alluvium (Unit 5), a cluster of calcareous fragments, some showing Middle Paleolithic retouch evidence, testified to a previous occupation of the site. Neolithic levels were found only in the colluvial silts. Two different Neolithic levels were identified: a first, very thin one with scattered artifacts (Unit 3) and a second, at least 20 cm thick, with many lithic tools of various kinds, including several bipolar cores and points (Unit 1).
Some poorly preserved stone structures were partially excavated. They are assumed to rest on the alluvial deposits identified in the pit stratigraphy. Moreover, additional structures may lie in the still unexcavated sections. The settlement was probably not very large, considering the size of the HK/361 area, although its extent will be defined after completing the excavation of the whole site.
The major architectural feature is an oval structure (2.2×3.3 m; Fig. 1: I) whose entrance was in the south. The walls (thickness 0.5–0.8 m) were built of rough local lime stones (size 0.2–0.5 m). The less disturbed side shows a double row of large stones with a core of cobbles. The structure was not fully excavated; hence the maximum height of the walls could not be determined.
Small circles of four and five stones (0.2–0.3 m; Fig. 1: II–V) may have been postholes. Wooden posts may have supported a roof over an open courtyard.
Two other stone circles (Fig. 1: VI—diam. 0.5 m, VII—diam. 1 m) consisted of medium-sized stones (0.2–less than 0.3 m). These circles may have been fireplaces, although no ashes or bones were found in them.
Two other features uncovered in the excavation area were stone alignments (Fig. 1: VIII, IX).
The remarkable material culture included a rich blade-based flint assemblage (Fig. 4), dominated by distal blades (Fig. 4:1–4), i.e., thin blades with a sharp distal edge, perpendicular to the blade’s central axe and in some cases denticulate, which was achieved by detaching a flake along the blade central axe or through partial detachment. The presence of Jericho points (Fig. 4:5–7), Amuq points (not drawn) and bipolar naviform cores (Fig. 4:8) confirms that HK/361 belongs to the early PPNB. The highest number of flint artifacts (1795/sq m) came from the area immediately east of Structure I, with a rather low ratio (0.29) of implements/ total artifacts; it may have been a knapping centre for the preparation of flint tools. Fewer artifacts (N=660/sq m) and a higher implement/total artifacts ratio (0.37) were recovered from Structure I, indicating workshop activities, such as animal skin cutting and meat preparation. The so-called courtyard had even fewer artifacts (N=528/sq m), a higher implement ratio (0.40) and fragments of grindstones that point to seed grinding.
No faunal remains were found, apart from two gastropods (Cypraea spp.), likely to come from the Red Sea.
At the present state of research, HK/361 appears to be a PPNB settlement that subsisted on a mixed economy; hunting and gathering still continued in presence of an early agriculture, spurred by climatic improvement that occurred c. 12–10,000 years BP, during the humid Neolithic period that benefited Northern Africa and Sahara.