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Fig. 10. Direct active elements made of quartz slab fragments (DAEs): DAE-20E used for yam pounding, Type 6 damage. Note the two by-products detached; DAE-10A used for me enderizing, Type 9 damage. Note the by-products detached and how its original cuboid-shape is transformed into a subspherical-shape.

Figure 10 Direct active elements made of quartz slab fragments (DAEs): DAE-20E used for yam pounding, Type 6 damage. Note the two by-products detached; DAE-10A used for me enderizing, Type 9 damage. Note the by-products detached and how its original cuboid-shape is transformed into a subspherical-shape.

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Count of percussive tool types sorted by raw materials and blanks. Table 1
Count of percussive tool types sorted by raw materials and blanks. Table 1
Number of items processed, duration and participants in each percussive activity. Table 2
Number of items processed, duration and participants in each percussive activity. Table 2
Ground passive element (GPE): a passive element, commonly named anvil (AV), in which the upper face (Platform A) supports the Fig. 2. Percussive tools classification: 1) ground passive element (GPE); 2) direct active el- ement (DAE); 3) indirect active element (IAE); and 4) intermediate passive element (IPE).
Ground passive element (GPE): a passive element, commonly named anvil (AV), in which the upper face (Platform A) supports the Fig. 2. Percussive tools classification: 1) ground passive element (GPE); 2) direct active el- ement (DAE); 3) indirect active element (IAE); and 4) intermediate passive element (IPE).
Fig. 1. Range of percussive activities and organic substances battered: 1) overview of the slabs and cobbles quarried; 2) yams; 3) cow-flesh; 4) palm nuts; 5) ground knapping technique; 6) bipolar knapping technique; 7) wood chopping with wedge; 8) meat tenderizing; 9) nut cracking with wedge; 10) oldupai processing; 11) yam processing; 12) cow femur; and 13) cow bone breaking.
Fig. 1. Range of percussive activities and organic substances battered: 1) overview of the slabs and cobbles quarried; 2) yams; 3) cow-flesh; 4) palm nuts; 5) ground knapping technique; 6) bipolar knapping technique; 7) wood chopping with wedge; 8) meat tenderizing; 9) nut cracking with wedge; 10) oldupai processing; 11) yam processing; 12) cow femur; and 13) cow bone breaking.
Fig. 3. Type of percussion damage established through the combination of the distribution and density of the use-wear
Fig. 3. Type of percussion damage established through the combination of the distribution and density of the use-wear
Mean size (mm) and weight (g) of slabs and slab fragments sorted by blank types. Table 3
Mean size (mm) and weight (g) of slabs and slab fragments sorted by blank types. Table 3
Count of used slabs and slab fragments sorted by knapping method. Table 4
Count of used slabs and slab fragments sorted by knapping method. Table 4
Count of fracture planes sorted by knapping method. Table 5
Count of fracture planes sorted by knapping method. Table 5
The fatigue wear (impact-fractures and cracks) of the ground frag- ments are always concentrated on the platform that receives the strikes (Platform A), with greater incidence on the surface than on the ridges. There is no use-wear on the platform that is in contact with the ground (Platform B), because the ground absorbs much of the blow force (Table 6) (Fig. 4). Many more blows are required to break a block using the ground technique than using the bipolar technique (3:1), par- ticularly when its volume is progressively reducing. For that reason, use-wear traces are more abundant and connected on Platform A of the ground fragments than on Platform A of the bipolar fragments (Table 6). Conversely, the rebound effect generated by the bipolar 44 slabs of different sizes were quarried by the authors on the slopes of Naibor Soit (Table 3). The bipolar technique was used to split 10 slabs and the ground technique was used in 7 slabs (Table 4). There are no significant typometrical differences among the slabs broken by each technique (Table 3). Both techniques are effective to break a slab into Fig. 4. Ground slabs (GS) broken into fragments and ground slab fragments (GSF). Platform A (dot). Platform B (cross)
The fatigue wear (impact-fractures and cracks) of the ground frag- ments are always concentrated on the platform that receives the strikes (Platform A), with greater incidence on the surface than on the ridges. There is no use-wear on the platform that is in contact with the ground (Platform B), because the ground absorbs much of the blow force (Table 6) (Fig. 4). Many more blows are required to break a block using the ground technique than using the bipolar technique (3:1), par- ticularly when its volume is progressively reducing. For that reason, use-wear traces are more abundant and connected on Platform A of the ground fragments than on Platform A of the bipolar fragments (Table 6). Conversely, the rebound effect generated by the bipolar 44 slabs of different sizes were quarried by the authors on the slopes of Naibor Soit (Table 3). The bipolar technique was used to split 10 slabs and the ground technique was used in 7 slabs (Table 4). There are no significant typometrical differences among the slabs broken by each technique (Table 3). Both techniques are effective to break a slab into Fig. 4. Ground slabs (GS) broken into fragments and ground slab fragments (GSF). Platform A (dot). Platform B (cross)
Location of use-wear sorted by slab fragment typ. Table 6 hammerstones (slab against slab) but no slab was broken. We tried to throw a slab against a ground slab without positive results.
Location of use-wear sorted by slab fragment typ. Table 6 hammerstones (slab against slab) but no slab was broken. We tried to throw a slab against a ground slab without positive results.
Fig. 5. Bipolar slabs broken into fragments (BS) and bipolar slab fragments (BSF). Platform A (dot). Platform B (cross). The bipolar technique was also employed to shape 11 fragments (10 bipolar fragments and 1 ground fragment) in order to adapt their shape and size to percussion tasks, enhancing their grip and handling. Comparing the bipolar fragments, use-wear traces are more abundant in both platforms and almost in the same proportion on their surfaces and ridges (Table 6). In terms of density and distribution, fatigue wear traces are loose or covered and connected. 87.5% of the bipolar frag- ments have fatigue traces on both platforms. Such abundance of fatigue wear is due to the sum of two reduction processes (slab fragmentation and fragment shaping) carried out by the bipolar technique. As a result, both platforms are progressively reduced, the longitudinal or oblique fractures of the detachments increase and thus the planes of fracture become more irregular (Fig. 6). Regarding the morphology of the fracture planes, the difference between both kinds of fragments is more attenuated. We have assessed the morphology of the length (longitudinal axis) and the width (transversal axis) of each fracture plane (Fig. 6). In both axes, the straight morphology reaches the highest values in both bipolar and ground fragments. However, in the former the values are slightly higher because the bipolar technique is characterized by wedge fracturing.
Fig. 5. Bipolar slabs broken into fragments (BS) and bipolar slab fragments (BSF). Platform A (dot). Platform B (cross). The bipolar technique was also employed to shape 11 fragments (10 bipolar fragments and 1 ground fragment) in order to adapt their shape and size to percussion tasks, enhancing their grip and handling. Comparing the bipolar fragments, use-wear traces are more abundant in both platforms and almost in the same proportion on their surfaces and ridges (Table 6). In terms of density and distribution, fatigue wear traces are loose or covered and connected. 87.5% of the bipolar frag- ments have fatigue traces on both platforms. Such abundance of fatigue wear is due to the sum of two reduction processes (slab fragmentation and fragment shaping) carried out by the bipolar technique. As a result, both platforms are progressively reduced, the longitudinal or oblique fractures of the detachments increase and thus the planes of fracture become more irregular (Fig. 6). Regarding the morphology of the fracture planes, the difference between both kinds of fragments is more attenuated. We have assessed the morphology of the length (longitudinal axis) and the width (transversal axis) of each fracture plane (Fig. 6). In both axes, the straight morphology reaches the highest values in both bipolar and ground fragments. However, in the former the values are slightly higher because the bipolar technique is characterized by wedge fracturing.
Fig. 6. Morphology of the fracture planes sorted by axis.
Fig. 6. Morphology of the fracture planes sorted by axis.
Mean size (mm) and weight (g) of the cuboid-shaped percussion tools used, sorted by blank and activity. Table 7
Mean size (mm) and weight (g) of the cuboid-shaped percussion tools used, sorted by blank and activity. Table 7
Fig. 7. Anvils: AV-7C, used for nut cracking; AV-27A and AV-36 used in multiple activities. Note that AV-36 does not present detached by-products (>20 mm) after use.
Fig. 7. Anvils: AV-7C, used for nut cracking; AV-27A and AV-36 used in multiple activities. Note that AV-36 does not present detached by-products (>20 mm) after use.
Count of direct active elements sorted by type of activity and type of damage. Table 8
Count of direct active elements sorted by type of activity and type of damage. Table 8
Fig. 8. Direct active elements of basalt cobbles (DAEs): DAE-86, used for ground breakage, Type 4 damage; DAE-2 used for bipolar breakage, Type 4 damage; DAE-61 for Flaking, Type 1 damage; DAE-80 used for bipolar, Type 1 damage; DAE-55 used for bipolar and ground breakage, Type 4 damage; and DAE-42 used for ground, Type 4 damage.
Fig. 8. Direct active elements of basalt cobbles (DAEs): DAE-86, used for ground breakage, Type 4 damage; DAE-2 used for bipolar breakage, Type 4 damage; DAE-61 for Flaking, Type 1 damage; DAE-80 used for bipolar, Type 1 damage; DAE-55 used for bipolar and ground breakage, Type 4 damage; and DAE-42 used for ground, Type 4 damage.
Fig. 9. Direct active elements made of quartz cobbles (DAEs): DAE-100 used for flaking, Type 8 damage; DAE-6 used for flaking, Type 8 damage; and DAE-67 and DAE-89 used for flaking, Type 5 damage.
Fig. 9. Direct active elements made of quartz cobbles (DAEs): DAE-100 used for flaking, Type 8 damage; DAE-6 used for flaking, Type 8 damage; and DAE-67 and DAE-89 used for flaking, Type 5 damage.
Mean size (mm) and weight (g) of the used cobbles sorted by activities. Table 9
Mean size (mm) and weight (g) of the used cobbles sorted by activities. Table 9
Fig. 11. Indirect active element (IAE): IAE-93 used for nut cracking and wood chopping, Type 8 damage; IAE-13C used for wood chopping, Type 2 damage; and IAE-43C used for nut cracking, Type 5 damage.
Fig. 11. Indirect active element (IAE): IAE-93 used for nut cracking and wood chopping, Type 8 damage; IAE-13C used for wood chopping, Type 2 damage; and IAE-43C used for nut cracking, Type 5 damage.
Fig. 12. Used dihedral angles: DAE-17A used for plant processing, the dihedral used show fatigue wears (frosted appearance); IPE 7B used for nut cracking, the dihedral used does not show fatigue wears.
Fig. 12. Used dihedral angles: DAE-17A used for plant processing, the dihedral used show fatigue wears (frosted appearance); IPE 7B used for nut cracking, the dihedral used does not show fatigue wears.
Fig. 13. Used dihedral angles: MPE-9B used for nut cracking and wood chopping. It shows broad areas with a high density of percussion marks (frosted appearance) due to its use as indirect active element and intermediate passive element. Type 8 damage. The used dihedral angle (highlighted in red) does not show fatigue traces; IPE-21B used for nut cracking and wood chopping. The used dihedral angle (marked in red) does not show fatigue traces, and in the opposite region there is a broad and round-shaped area with high density of fatigue wear (frosted appearance). (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)
Fig. 13. Used dihedral angles: MPE-9B used for nut cracking and wood chopping. It shows broad areas with a high density of percussion marks (frosted appearance) due to its use as indirect active element and intermediate passive element. Type 8 damage. The used dihedral angle (highlighted in red) does not show fatigue traces; IPE-21B used for nut cracking and wood chopping. The used dihedral angle (marked in red) does not show fatigue traces, and in the opposite region there is a broad and round-shaped area with high density of fatigue wear (frosted appearance). (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)
Fig. 14. Sub-spheroids made of quartz slab fragments: According to their shape, the experimental percussion tool (DAE-10A) and two of the archaeological percussion tools unearthed in SHK MS at Olduvai Gorge (SHK-239 and SHK-673) could be classified as sub-spheroids. In all of them the percussion marks show a covered distribution and connected density (Type 9), generating few areas with frosted appearance.
Fig. 14. Sub-spheroids made of quartz slab fragments: According to their shape, the experimental percussion tool (DAE-10A) and two of the archaeological percussion tools unearthed in SHK MS at Olduvai Gorge (SHK-239 and SHK-673) could be classified as sub-spheroids. In all of them the percussion marks show a covered distribution and connected density (Type 9), generating few areas with frosted appearance.
Related topics:
Experimental ArchaeologyLower PaleolithicEvolution and Human BehaviorStone toolsAfrican Early Stone AgePercussive Technology
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