Heavily fractured artefacts comprise of between zero (Level III, spits 4 and
5) and 57% (surface) of the analysed artefact assemblage for each level.
However as the small number of artefacts from the surface could have
been subjected to damage from site disturbance these results should be
treated with caution.
93 D isco u n tin g th e surface level, Level II, S p it 1 h ad th e h ig h est
p e rc en ta g e of h e av ily fra c tu re d designed tools (29.3%), suggesting th a t h ig h e r n u m b e rs of u se d a rte fa c ts h a d been discarded d u rin g th is period th a n d u rin g an y o th e r (M cBryde, 1974:236). Level II. 1 h a s a sim ilar d a te to t h a t of Level I of T rench 2 in GB1, w hich also contains th e h ig h est p e rc en ta g e of h eav ily frac tu re d a rtefacts in th a t site. T herefore it a p p ea rs t h a t th e p e ak period of tool use activity occurred in bo th sites a t a sim ila r tim e. Level II, sp it 1 also contained th e h ig h est percen tag es of heavily fra c tu re d reto u c h ed scrap ers an d u tilise d flakes. The h ig h est p ercen tag e of h eav ily fra c tu re d backed blades occurred in Level III, sp it 1 (if the sm all sam ple from th e su rface is discounted). A lthough it ap p ears t h a t backed b lad e u tilis a tio n p e ak e d a t th is level, slightly e arlie r th a n th e p eak u sage of sc rap e rs a n d u tilise d flakes, the figures are only re p re se n ta tiv e of zones (e) a n d (f), n o t th e w hole site (the backed blades exam ined w ere sam pled p re d o m in a n tly from th e s e two zones).
In th e oldest occupation layers, Level III sp its 2-5, few heavily fra c tu re d a rte fa c ts w ere found, in d icatin g a low incidence of tool use d u rin g th e e a rlie s t occupation of th e site. A t th e top of Level III (spit 1) h eav ily edge fra c tu re d a rte fa c ts reached a slig h t p eak re p re se n tin g 21% of th e flak ed designed tools. T he figure d ecreased ag ain a t th e bottom of Level II (sp its 2 a n d 3) w here th e level of heavy fra c tu rin g rem ain ed stead y
a t a ro u n d 13%. T his suggests th a t tool use activity in creased over th a t of e a rlie r occupation la y e rs b u t still rem ain ed a t a fairly low level. A t Level II sp it 1 th e p e rc en ta g e of heavy frac tu rin g in creased su b s ta n tia lly to j u s t u n d e r 30%, th e h ig h e s t p ercen tag e of heavily frac tu re d a rte fac ts for any level. T his p eak probably re p re se n ts th e period of g re a te s t tool use activity a t th e site, as th e a m o u n t of edge frac tu rin g declined in h ig h er levels. By Level I th e a m o u n t of h eav y fra c tu rin g h ad declined by m ore th a n te n p e r cen t a n d as su ch it a p p e a rs th a t less tool use activity occurred d u rin g th is occupation period th a n w as th e case as early as Level III sp it 1.
In site GB4 th e g re a te s t am o u n t of stone tool use a p p ears to have occurred d u rin g th e p erio d in w hich Level II, sp it 1 w as lain down, ap p ro x im ately 2000 to 2400 y ears ago. H ow ever th e g re a te s t am o u n t of u sed backed b lad e d iscard in th e site ap p ears to have occurred slightly e a rlie r a t Level III, sp it 1 app ro x im ately 3800 y ears ago (Level III, sp it 4, 3830 ± 100, Level II, spit 3, 3820 ± 110, (McBryde, 1974:375-6)).
94
V ariations in use of various forms of artefacts - GB1 and GB4 Backed blades
In both sites the pattern of backed blade distribution mirrors th a t of the distribution of all artefacts examined except for Level III.5 which contained no backed blades. The first dated level in which backed blades occurred a t GB4 is Level HE, Spit 4 a t 3830 ± 100 BP (Gak 1533). However in GB1 backed blades were present, both heavily fractured and less so, at the basal level of Level H, spit 2 and Trench 2 dated to 3900 BP and the basal level of Trench 1 dated to 5400 BP.
Although backed blades were manufactured at GB1 earlier th an at GB4, very few used examples were discarded at GB1 during early
occupation of the site. In contrast, at GB4 large numbers of utilised
backed blades were discarded between approximately 3800 BP and 3200 BP. By 2400 BP backed blade production and use appears to have declined at GB4. At GB1 discard of utilised backed blades reached a peak between 2700 and 2000 BP.
Despite their different time scales, both sites exhibit similar
discard patterns for backed blades. At both GB1 and GB4 the main areas w ithin the site where such activitity appears to have been concentrated were in or near the overhang areas of the sites, although in GB1 there is a change in production/use/discard zones for backed blades.
In Trench 2 a t GB1 backed blade production, utilisation and
discard areas dating between 3900 and 2700 BP were concentrated in zone (c) which is bisected by the edge of the shelter overhang. By 2000 BP, backed blade production, utilisation and discard appears to have shifted further away from the overhang to zone (d), completely outside the shelter. U tilised flakes
At GB1 utilised flakes were present from the lowest dated levels (3900 BP in Trench 2, 5400 BP in Trench 1) through to Level I dated to 2000 BP. No utilised flakes were found in the surface level. The peak period of flake use in GB1 occurred around 2000 BP. In GB4, heavily utilised flakes were absent in the lowest level, but peaked in number at around 2400 BP. They were present in the site from Level III spit 1 at approximately 3800
95 BP to the surface level, and whilst they did not appear as early as they did
in GB1, the peak discard period occurred earlier at GB4.
D istribution of use and discard areas for utilised flakes varied temporally at both sites. In Trench 2 of GB1 these areas changed from zone (d) at 3900 BP to zone (c) at 2700 BP and to zone (e) at 2000 BP.
However all of these zones are situated under or outside the shelter overhang. Utilised flakes occurred only rarely in areas within the overhang of the shelter.
At GB4 utilised flake utilisation and discard areas also changed from zone (e) at 3800 BP to zone (f) at 3200 BP, back to zone (e) at 2400 to 2000 BP and to zone (c) at the surface levels (post 1700 BP). Each of these zones, with the exception of zone (c), lie adjacent to or outside the overhang of the shelter.
At GB1 utilised flake discard rates peaked at the same period as th a t for backed blades, however at GB4 utilised flake discard peaked at a period when backed blade manufacture and use was in decline a t around 2400 BP.
Retouched scrapers
Retouched scrapers were the only artefacts to have been produced, used and discarded at all dated levels of both sites. Scrapers were present in GB1 from 5400 to 2000 BP and in GB4 between 3800 and 1700 BP.
However heavily fractured scrapers only occurred in GB1 between 2700 and 2000 BP and in GB4 between 3820 and 1700 BP. The peak period of used scraper discard at GB1 was 2700 BP and at GB4 3800 BP. The GB1 scraper production,use and discard peak occurred earlier for scrapers th an for any other major tool type, but at GB4 the peak conformed with th a t of other artefact forms except for backed blades and utilised flakes. The m ain production/use/discard area for scrapers in GB1 rem ained in zone (c) throughout all levels of the deposit with the exception of the surface where most scrapers were located in zones (a) of both trenches. In GB4 scraper production, use and discard remained concentrated in zone (e) at all levels of the site.