Flaking properties, petrology and use of Polish flint.

Flaking properties, petrology and use of Polish flint. Introduction From the Middle Palaeolithic to Early Bronze Age Bronze Age,period in the development of technology when metals were first used regularly in the manufacture of tools and weapons. Pure copper and bronze, an alloy of copper and tin, were used indiscriminately at first; this early period is sometimes called the , flint was usedextensively in Poland for stone tool manufacture (Lech Lech(lĕkh), river, c.175 mi (280 km) long, rising in Vorarlberg, W Austria, and flowing NE into S Germany past Augsburg to the Danube River. The Wertach River is its chief tributary. 1981; Balcer1983). Three different flint types were mined around the Holy CrossMountains of southeastern Poland (FIGURE 1) (chocolate, greywhite-spotted and banded flint), each for a different purpose (short orlong blades and partly polished or polished axes). The reasons for theseparate usage for each flint type relate to both mechanical andphysical properties and aesthetic appearance. [Figure 1 ILLUSTRATION OMITTED] Recent experimental studies (Domanski & Webb 1992; Domanski etal. 1994) have used mechanical properties, particularly fracturetoughness In materials science, fracture toughness is a property which describes the ability of a material containing a crack to resist fracture, and is one of the most important properties of any material for virtually all design applications. , to define the flaking properties of stone artefact See artifact. materials.These studies showed that fracture toughness, which measures theresistance of a material to catastrophic fracture propagation, is themost objective and important measure of the quality of stone toolmaterials. Lithic lith��ic?1?adj.Consisting of or relating to stone or rock.Adj. 1. lithic - of or containing lithium2. lithic - relating to or composed of stone; "lithic sandstone" materials most amenable to blade manufacture andpressure flaking (obsidian) have low values of fracture toughness,whereas those shaped into axes by pecking and grinding (greenstone green��stone?n.Any of various altered basic igneous rocks colored green by chlorite, hornblende, or epidote.greenstoneNounNZ a type of green jade used for Maori carvings and ornaments ) havevery high values (FIGURE 2) (Domanski et al. 1994: 203, figure 5). [Figure 2 ILLUSTRATION OMITTED] These results are here applied to the three different types ofPolish flint from the Holy Cross Mountains, in order to relate thedifferent uses to which these flints were put to their fracturetoughness and petrology petrology,branch of geology specifically concerned with the origin, composition, structure, and properties of rocks, primarily igneous and metamorphic, and secondarily sedimentary. . However, before discussing the Polish flints indetail, it is first necessary to review the general characteristics ofartefact materials used for blade and ground tool technology, and thedifferences between them. Flaking properties of raw materials used in blade technology For blade manufacture, the lithic materials normally favoured werehomogenous homogenous - homogeneous and isotropic Refers to properties that do not differ no matter which direction is measured. For example, an isotropic antenna radiates almost the same power in all directions. In practice, antennas cannot be 100% isotropic. microcrystalline microcrystalline/mi��cro��crys��tal��line/ (-kris��tah-lin) made up of minute crystals. microcrystallinemade up of minute crystals. siliceous siliceousrelating to or made of silica or a silicate. lithologies. Inthese rock types, the lack of direction-dependent properties means thatflake detachment is determined only by the stress distribution duringthe flaking event, and is more readily controlled by the knapper(Cotterell & Kamminga 1987; Crabtree 1968: 457-9). Raw materials amenable to blade manufacture and pressure flakinghave low values of fracture toughness and high rankings of macroscopic macroscopic/mac��ro��scop��ic/ (mak?ro-skop��ik) gross (2). mac��ro��scop��icor mac��ro��scop��i��caladj.1. Large enough to be perceived or examined by the unaided eye.2. uniformity (Domanski et al. 1994: 203, tables 4 & 5). Obsidian isgenerally regarded as the easiest material to work for flaked stonetools (Bordes 1969: 14; Callahan 1979: table 3), because it requiresless force than other lithologies to detach flakes, and it has a lowfracture toughness (median 24-27 MPa.[mm.sup.1/2]) and high macroscopicuniformity (Domanski et al. 1994: table 5). Glass Buttes obsidian ofcentral Oregon Central Oregon is a geographical region lying near the center of the U.S. state of Oregon. It is commonly considered to include Deschutes, Jefferson, and Crook counties. Primary cities in Central Oregon are La Pine, Sunriver, Bend, Redmond, Madras, and Prineville. was graded at 1.0 on Callahan's scale of `ease ofworkability' (Callahan 1979: table 3), and has a fracture toughnessof about 26 MPa.[mm.sup.1/2] (FIGURE 2). Flaking properties of lithologies used in ground tool technology Raw materials used for ground stone cutting tools are shaped bypecking and grinding. During pecking hundreds of sharp blows aredelivered to the blank, which must be very tough, resistant to fractureand free of cracks and other flaws (Fenton 1984: 223). Fine- tomedium-grained rocks with strongly interlocking textures or strongintergranular bonds are preferred (Fenton 1984: 231), e.g. metamorphosedbasic volcanics (greenstones). The low quartz content of greenstonesalso makes them softer and easy to grind (Dickson 1981: 106-7). Forexample, Mount William greenstone of southeastern Australia was widelyused to make ground-edge axes (McBryde 1978: 355-6). This lithology li��thol��o��gy?n.1. The gross physical character of a rock or rock formation.2. The microscopic study, description, and classification of rock. is afine-grained metabasalt composed of interlocking, randomly orientedactinolite actinolite(ăktĭn`əlīt): see amphibole. actinoliteColourless to green amphibole mineral, darkening with increased iron content from green to black. crystals, and has very high values of fracture toughness(median 105-130 MPa.[mm.sup.1/2]) (FIGURE 2) and high rankings ofmacroscopic uniformity (Domafiski et al. 1994: 193,197, table 6),explaining its mechanical superiority in the manufacture of ground-edgeaxes. Polish flint During the Palaeolithic, Mesolithic, Neolithic and early BronzeAge, more than 10 different flint types were used extensively in Polandfor stone tool manufacture (Balcer 1983: 46-52). Most flint productionwas based on five flint types: Cracow-Wielun Jurassic flint from theCracow region, Volhynian flint imported from the Volhynian Upland in thewestern part of the Ukrainian Republic, chocolate flint from the Radomarea, grey white-spotted (Swieciechow) flint from the Annopol area andbanded (Krzemionki) flint from the Ostrowiec Swietokrzyski region. Thelatter three (chocolate, grey white-spotted and banded flints) wereselected for detailed study because archaeological records show thatthey were extensively mined at separate mining complexes, used fordifferent tool types and for different reduction strategies, and oftentransported over long distances. Occurrence and usage Chocolate flint occurs in the Upper Jurassic (Lower Kimmeridgian)limestone and overlying overlyingsuffocation of piglets by the sow. The piglets may be weak from illness or malnutrition, the sow may be clumsy or ill, the pen may be inadequate in size or poorly designed so that piglets cannot escape. residual karstic clays on the northeasternfootslopes of the Holy Cross Mountains in central Poland (FIGURE 1). Thechocolate flint deposits form a northwest-southeast belt some 50 km longand 3-6 km wide between the Radomka and Kamienna Rivers (Schild 1987:137-9). Chocolate flint occurs as rounded or flat nodules and thin tomedium-thick slabs, usually less than 20 cm in length and 10 cm inthickness. It has uniform macroscopic structure and excellent flakingproperties, and was used to make small and medium-sized blade tools, butnot polished axes (Schild 1987: 142-7). Grey white-spotted (Swieciechow) flint occurs in mid-Cretaceous(Lower Turonian) limestones of the Rachow Anticline along the middleVistula River Vistula RiverPolish WislaRiver, Poland. It rises on the northern slope of the Carpathian Mountains in southwestern Poland, flows in a curve through Warsaw and Torun, then empties into the Baltic Sea at Gdansk. Most of its 651 mi (1,047 km) are navigable. between Annopol, Swieciechow and Goscieradow (FIGURE 1).Weathering of the limestone during the Tertiary formed a residual soil Noun 1. residual soil - the soil that is remaining after the soluble elements have been dissolvedresidual claydirt, soil - the part of the earth's surface consisting of humus and disintegrated rock containing abundant flint concretions; this material was largely washeddown into the Vistula valley in the Pleistocene (Balcer 1976: 179-82).At Swieciechow-Lasek, on the eastern slope of the Vistula valley, flintconcretions up to 46 cm across were extensively mined from thetransported soil and rubble. Swieciechow flint has good flakingproperties and was used to make long blades and large partly polishedaxes (Balcer 1976: 190-6; 1988: 67). Banded flint occurs in the Upper Jurassic (Upper Oxfordian)limestone outcropping on the northeastern perimeter of the Holy CrossMountains (FIGURE 1), in the vicinity of the chocolate flint sources butat a stratigraphically slightly lower horizon (Borkowski et al. 1991:608,611; Budziszewski & Michniak 1984: 158-70). It occurs as bigrounded concretions up to 90 cm in diameter. The concretions are oftencracked, and the entire formation is crisscrossed by faults andfissures. Banded flint has poor flaking properties (Balcer 1983: 50;Balcer & Kowalski 1978: 132), and it was preferentially used for themanufacture of completely polished axes, smaller than the Swieciechowflint axes (Borkowski et al. 1991: 607). It was extensively mined in theKrzemionki Opatowskie area (FIGURE 1). Petrology Chocolate flint is a uniform brown (10 YR 4/4) colour with a paleyellow (2.5 Y 8/3) cortex 2-5 mm thick, typical conchoidal fracture Conchoidal fracture describes the way that brittle materials break when they do not follow any natural planes of separation. Materials that break in this way include flint and other fine-grained minerals, as well as most amorphous solids, such as obsidian and other types of glass. andno visible macroscopic defects (FIGURE 3A). It has a relativelynon-uniform microstructure mi��cro��struc��ture?n.The structure of an organism or object as revealed through microscopic examination.microstructureNouna structure on a microscopic scale, such as that of a metal or a cell . The fine-grained groundmass groundmass:see porphyry. (85-90%),composed of quartz crystals averaging 5-10 [micro]m across, containsscattered small patches (up to 2 mm in diameter) of chalcedonic chal��ced��o��nyalso cal��ced��o��ny ?n. pl. chal��ced��o��niesA translucent to transparent milky or grayish quartz with distinctive microscopic crystals arranged in slender fibers in parallel bands. silica(10-15%). These represent replaced fossils, e.g. bryozoans, or infilledmicrofossil mi��cro��fos��sil?n.A microscopic fossil, as of a pollen grain or unicellular organism.microfossil?A microscopic fossil, as of a pollen grain or unicellular organism.Noun 1. cavities (FIGURE 4A), and comprise fibrous grains averaging25 [micro]m across. There are also occasional larger cavity infillscomposed of a thin chalcedonic rim surrounding a mosaic ofinclusion-rich quartz crystals averaging 40 [micro]m across. [Figures 3-4 ILLUSTRATION OMITTED] Grey white-spotted (Swieciechow) flint is a greyish brown Noun 1. greyish brown - a color or pigment varying around a light grey-brown color; "she wore dun"fawn, grayish brown, dunlight brown - a brown that is light but unsaturated (7.5 YR4/2) colour with a light grey (2.5 Y 8/2) cortex reaching 8 mm inthickness. It has a typical conchoidal fracture and contains abundantlight grey (2.5 Y 8/2) spots up to 3 mm across (FIGURE 3B). There are novisible macroscopic defects. It has a relatively non-uniform microstructure, comprising afine-grained groundmass (70%) of quartz crystals (up to 5 [micro]macross) with scattered abundant small chalcedonic areas (25%), calcite calcite(kăl`sīt), very widely distributed mineral, commonly white or colorless, but appearing in a great variety of colors owing to impurities. crystals (4%) and tiny opaque minerals (1%) (FIGURES 5A & 5B). Thecalcite crystals and chalcedonic areas are 20 [micro]m-0.1 mm across;the latter represent replacements of microfossils, mostly spongespicules and planktonic plank��ton?n.The collection of small or microscopic organisms, including algae and protozoans, that float or drift in great numbers in fresh or salt water, especially at or near the surface, and serve as food for fish and other larger organisms. forams. The opaque minerals are very small(average 5 [micro]m, but up to 0.1 mm) and probably mostly pyrite pyrite(pī`rīt)or iron pyrites(pīrī`tēz, pə–, pī`rīts), pale brass-yellow mineral, the bisulfide of iron, FeS2. . Thewhite spots visible in hand specimen are areas with a brownstainedgroundmass, so that the microfossil outlines within them stand outclearly. [Figure 5 ILLUSTRATION OMITTED] Banded flint is composed of greyish brown (7.5 YR 4/2) and brownishgrey (7.5 YR 6/2) bands in a distinctive pattern (FIGURE 3C), with avery thin ([is less than] 0.5 mm) off-white and dark greyish yellow (2.5Y 5/2) cortex. Macroscopic defects are evident in the form of shortcracks below the cortex. Banded flint has a very uniform microstructure composed of afine-grained groundmass (95%) of quartz crystals 5-20 [micro]m across,with scattered occasional patches of microquartz (3%), opaque minerals(2%) and tiny calcite crystals ([is less than] 1%). The microquartzpatches, 20-50 [micro]m across, are replaced microfossils (FIGURE 4B).There is little difference in microstructure between the dark and lightbands that are so obvious in hand specimen, and Budziszewski &Michniak (1984: 170-80) found the bands had the same mineralogy andchemical composition. Mechanical testing Methods Testing for fracture toughness and ranking of macroscopicuniformity followed the procedure outlined in Domanski et al. (1994:186-8) and Whittaker et al. (1992: 262-7), using cylinders 15 mm indiameter and 21.75 mm long. Only visually uniform specimens wereselected for testing. A statistical analysis of variability in the fracture toughness offlint samples showed that one sample of flint from a particular localityis reasonably representative of that lithology (Domanski et al. 1994:189,193). Therefore, even though it was possible to test only one sampleof one Polish flint type (chocolate flint), it is believed that thefracture toughness and ranking of macroscopic uniformity obtained arerepresentative of that lithology. Results Chocolate flint has a relatively low fracture toughness (53MPa.[mm.sup.1/2]), a small 95% confidence interval confidence interval,n a statistical device used to determine the range within which an acceptable datum would fall. Confidence intervals are usually expressed in percentages, typically 95% or 99%. (TABLE 1, FIGURE 2),and a ranking of macroscopic uniformity of 1. The fracture toughnessapproaches that of obsidian and heat-treated microcrystalline siliceousmaterials (which are ideal for blade manufacture and pressure flaking),and is less than that of most flint samples world-wide (49-83MPa.[mm.sup.1/2]; Domanski & Webb 1992: 605-6; Domanski et al. 1994:203). The low fracture toughness and uniform macrostructure The notion of macrostructure has been used in several disciplines in order to distinguish large-scale, or 'global' structures, from small-scale, or 'local' structures, that is, microstructures. of chocolateflint explain its excellent flaking properties and preferential use forthe manufacture of blades and microblades. The low resistance totraumatic fracture was a marked advantage in blade technology. The smallsize of the nodules and slabs of chocolate flint restricted its use tothe production of relatively small and medium-sized blades (less than 10cm long). TABLE 1. Fracture toughness and ranking of macroscopic uniformityof Polish flint.Sample Collection LocalityNumber (Figure 1) 345 a flint workshop at the Rydno ochre mining complex, Radom District, central Poland 346 Swieciechow-Lasek mine, Lublin District, central Poland 347 as above 348 as above 349 Krzemionki Opatowskie mine, near Ostrowiec Swietokrzyski, central Poland 350 as above 350(*) as above350(**) as above 351 as above Fracture Toughness (MPa.[mm.sup.1/2]) No. of No. ofSample Spec. TestsNumber Flint Type Tested Valid 345 chocolate flint 12 11 346 grey white-spotted flint 12 12 347 as above 12 12 348 as above 12 12 349 banded flint 11 10 350 as above 18 16 350(*) as above 11 10350(**) as above 7 6 351 as above 7 5Sample Fracture Toughness Ranking ofNumber (MPa.[mm.sup.1/2]) Uniformity Median and 95% uncertainty +7.26 345 53.39 -1.98 1 +5.76 346 65.39 -2.52 1 +3.71 347 61.52 -1.25 1 +1.79 348 60.76 -3.66 1 +13.09 349 67.04 -5.31 5 +10.18 350 82.90 -12.35 8 +10.44 350(*) 82.64 -12.65 as above +23.07350(**) 83.20 -3.02 as above +16.23 351 81.59 -18.91 5SampleNumber Bibliographic References 345 Schild 1984, 1987 346 Balcer 1976 347 as above 348 as above 349 Budziszewski and Michniak 1984 Borkowski et al. 1991 350 as above 350(*) as above350(**) as above 351 as above Grey white-spotted flint has a fracture toughness of 60-65MPa.[mm.sup.1/2], a small 95% confidence interval, and a ranking ofmacroscopic uniformity of 1 (TABLE 1). The moderate fracture toughnessand uniform macrostructure make this flint suitable for the manufactureof both blades and polished axes. The slightly higher fracture toughnesscompared to chocolate flint indicates that more force is required todetach flakes from grey white-spotted flint (FIGURE 2; TABLE 1).However, this toughness and resistance to fracture make tools of spottedflint less likely to break during preparation, and more durable duringheavy-duty activities, so spotted flint is amenable to ground-edge axemanufacture. Compared to greenstone, flint is harder (as it is composedof quartz rather than softer minerals like feldspar feldspar(fĕl`spär, fĕld`–)or felspar(fĕl`spär), an abundant group of rock-forming minerals which constitute 60% of the earth's crust. and amphibole amphibole(ăm`fəbōl'), any of a group of widely distributed rock-forming minerals, magnesium-iron silicates, often with traces of calcium, aluminum, sodium, titanium, and other elements. ) andfiner grained. As a result, a spotted flint axe A flint axe was a tool used during prehistoric times to do a variety of tasks. These were at first just a cut piece of flint stone but later handles were attached to these axe heads. Flint axes were also used as a weapon. takes a sharper edgethan an axe made of greenstone, although it would be more difficult togrind and less durable (because of its lower fracture toughness; FIGURE2). The occurrence of spotted flint as large rounded concretions, easilyextracted from the soil and rubble, meant that large artefacts could bemanufactured; the blades and axes are typically 17.4 and 16.1 cm longrespectively (Balcer 1983:272; 1988: 70). Banded flint displays the highest fracture toughness of the Polishflint samples tested (67-83 MPa.[mm.sup.1/2], the largest 95% confidenceinterval, and a markedly lower ranking of macroscopic uniformity due tothe presence of short macroscopic cracks (TABLE 1). Mechanical tests ofone sample (no. 350), using cylinders with long axes either parallel orperpendicular to the colour banding, found no significant difference inthe fracture toughness of the two orientations (TABLE 1). The high fracture toughness of banded flint (approaching that ofgreenstone; FIGURE 2), coupled with its non-uniform macroscopicstructure, make this material difficult to flake and less suitable forblade manufacture due to difficulties in establishing core ridges,preparing core platforms and detaching long parallel-sided blades. It ismuch easier to strike off regular blades from grey white-spotted flintthan from banded flint. However, as discussed above, lithologies withhigh fracture toughness are much more suitable for axes, as they areresistant to traumatic fracture and more durable. Thus banded flint wasextensively used for axe manufacture. Banded flint concretions are up to 90 cm across, butmacroscopically mac��ro��scop��ic? also mac��ro��scop��i��caladj.1. Large enough to be perceived or examined by the unaided eye.2. Relating to observations made by the unaided eye. uniform axe blanks obtained from the concretions aremuch smaller than this because of the abundant cracks, and banded flintaxes are typically only 10.9 cm long (Balcer 1988: 84). Axe of greywhite-spotted flint were larger, because this material could beextracted as large uniform blocks. Relationship between petrology and mechanical properties To understand how the mechanical properties of Polish flint aredetermined by its microstructure, it is first necessary briefly toreview the factors that determine the strength of rocks. Inmicrocrystalline rocks, cracks grow along grain boundaries(intergranular fracture An intergranular fracture is a fracture that follows the grains of the material. If the material has multiple lattice organizations, when one lattice ends and another begins, the fracture changes direction to follow the new grain. ; Kirchhof et al. 1982; Whittaker et al. 1992:301-3), and the strength of the rock is proportional to the contact areabetween the grains and inversely proportional to the grain size (Farmer1968: 13). Thus the larger the grain size, the larger the grainboundaries and therefore the intergranular cracks. For materials with alarge variation in grain size, the larger grains exert a controllinginfluence on fracture toughness (Rice et al. 1980). The resistance to fracture propagation is also determined by theenergy of the cohesive bonding between the constituent atoms ormolecules along the path of fracture (Lawn & Wilshaw 1975). Inmineralogically non-uniform flints comprising aggregates ofmicrocrystalline silica and calcite particles, the weaker calcitecrystals have a controlling influence on the fracture toughness, becausethe bonding in calcite is much weaker than the silicon-oxygen bond inquartz, which has one of the strongest bonds in common rock types(Whittaker et al. 1992: table A.1). The fracture toughness of the three types of Polish flint can bedirectly related to these factors. Banded flint has the most uniform,even-grained microstructure (FIGURE 4B), accounting for its highfracture toughness, even though the groundmass is slightly coarsergrained than in chocolate or spotted flints. Grey white-spotted flinthas a lower fracture toughness because it contains abundant smallchalcedonic inclusions and scattered calcite crystals (FIGURES 5A &5B). The relatively long grain boundaries within the chalcedonic patchesand the softness and cleavage of the calcite facilitate fracturepropagation and decrease the fracture toughness. Chocolate flintcontains less abundant chalcedonic inclusions than spotted flint andlacks calcite crystals, yet has a lower fracture toughness (FIGURE 2;TABLE 1). The controlling influence on fracture propagation in thislithology is the grain size and diameter of the inclusions, which aresubstantially larger and coarser-grained than in spotted flint (FIGURE4A). The long grain boundaries within the inclusions are responsible forthe relatively low fracture toughness of chocolate flint and itsexcellent flaking properties. Differential use of flint in blade technology in Poland Chocolate flint in the Masovian culture (Terminal Palaeolithic) The Late Palaeolithic Masovian hunters followed the seasonalmigrations of the reindeer herds through the tundra environment ofPoland and nearby areas, and applied a specialized raw material economyand advanced conservation strategies (Schild 1996: 135; 1984: 246) as anadaptive response The adaptive response is a form of direct DNA repair in E. coli that is initiated against alkylation, particularly methylation, of guanine or thymine nucleotides or phosphate groups on the sugar-phosphate backbone of DNA. to the harsh environment. The highly mobile huntersused a light portable tool kit of long thin blades and micro-blades withstraight parallel edges (Kozlowski & Kozlowski 1977: 196). Abouthalf (c. 300) of the Masovian assemblages in Poland contain chocolateflint, most of which must have been extracted by mining (Schild 1984:246). Assemblages with [is greater than] 50% chocolate flint occur asfar as 200-225 km from the mines (Schild 1976: 165-9; 1984: 246-8). Chocolate flint was chosen preferentially because its low fracturetoughness (FIGURE 3A) gives it excellent flaking properties, so it isparticularly amenable to blade production (Crabtree 1968: 451; Clark1987: 266) and fine retouching. The low fracture toughness also meansthat chocolate flint has an unusually high resharpening potential;Masovian tools were often intensively modified by repeated resharpeningto extend their use-life. Chocolate flint in the Linear Pottery (Early Neolithic) andLengyel-Polgar (Middle Neolithic A) cultures The flaking industries of the first farming communities in theEarly and early Middle Neolithic were directed towards the production ofrelatively short blades, generally 4-6 cm long (Lech 1982/83: 19). Manyof these blades were used in composite sickles, made up from 3-5 shortflint segments inserted into a bone or wooden handle (Lech 1982/83: 6-7;Balcer 1983: 40-43; 1988: 54, 57, 61). Chocolate flint was ideallysuited for the production of sickle blades, because of its excellentflaking properties and high resharpening and edge-holding potential(discussed above). It often dominates Early and early Middle Neolithiclithic assemblages as far as 300 km from the source (Balcer 1988: 57;Schild 1976: 171; 1987: 145,147). The demand for substantial quantitiesof chocolate flint could only be met by extensive underground mining,which reached its peak in the late Lengyel-Polgar complex (Schild1987:139,142; Balcer 1983: 120). The late Middle and Late Neolithic flaking industries were based onthe production of much larger flint blades (see below); such bladescould not be produced from chocolate flint because of the relativelysmall size of the nodules. As a result, the Middle and Late Neolithicusage of chocolate flint was relatively restricted, and its geographicaldistribution was much more limited, within 50-100 km radius of the mines(Balcer 1983: 227; Schild 1987: 145-7). Grey white-spotted (Swieciechow) flint in the Funnel Beaker culture(Middle Neolithic B) In the Middle Neolithic the composite sickle of the first farmingcommunities was gradually replaced by a sickle using one long massiveflint blade with straight parallel edges (Balcer 1983: 40-43; Lech1982/83: 6-7). A single-blade sickle is more efficient in harvestingcrops (Korobkova 1978; cited in Balcer 1983: 42), is more durable andcan be resharpened more often, decreasing the frequency of toolreplacement (Balcer 1983: 40-43; Hayden 1987: 36, 39, 41). The specialized mass production of massive flint blades 10-30 cmlong required a reliable supply of substantial quantities of flintnodules of the appropriate quality and size, and grey white-spotted(Swieciechow) flint and Volhynian flint were preferentially used forthis purpose (Balcer 1983: 50; Lech 1982/83: 25-7). In the Funnel Beakerculture Swieciechow flint reached the apogee of its importance, with theproduction of raw, utilized and retouched blades typically 17.4 cm long(Balcer 1983: 272; 1988: 68, 70). Its good flaking properties(reflecting its moderate fracture toughness, TABLE 1), uniformmacroscopic structure (FIGURE 3B), presence as large rounded concretionsand ease of extraction (Balcer 1976: 188) all contributed to itspopularity. To satisfy the demand there was major underground mining anda specialized mass production of long massive blades, probably byspecialized flint craftsmen, in the immediate vicinity of the mines(Balcer 1983: 183-5; 1995: 219; Borkowski et al. 1991: 622-5). Theseblades were distributed within a radius of 470 km from the mine (Balcer1976: 192-5, 1983: 177,179; 1988: 67). Differential use of flint in ground stone technology in Poland Early Neolithic ground stone cutting tools The transition from Masovian hunter-gatherers to sedentary EarlyNeolithic agricultural communities resulted in extremely high woodcutting requirements (Hayden 1987: 40), for clearing land, buildinglonghouses and firewood. The most efficient and durable tools inheavy-duty woodworking activities are ground stone cutting implements;they have a much longer use-life than flaked tools because they can berepeatedly resharpened (Hayden 1987: 41). In north-central Europe, Early Neolithic farming communities usedground stone cutting tools manufactured from various metamorphic andbasic igneous rock types, particularly amphibolites (greenstones)(Bakels 1987; Prinke & Skoczylas 1980: table 1). These rock typesare tough and durable (Fenton 1984: 230-31) due to their very highfracture toughness (Domanski et al. 1994: table 6). Grey white-spotted (Swieciechow) flint axes in the Funnel Beakerculture (Middle Neolithic B) Social and economic changes in the Middle Neolithic greatlyaccelerated the rate of forest clearance and woodworking, and caused agradual replacement of the greenstone axes by ones made of polishedflint. Polished flint axes are more susceptible to traumatic: fracture(because of their lower fracture toughness; FIGURE 2) but take a sharperedge (as previously discussed), so they were ideal for splitting andplaning, and were also very efficient for cutting down trees (Olausson1983: 69; Mathieu & Meyer 1997: 343). They were probably usedprimarily for carpentry work, splitting firewood, and tending coppicewoods to provide fodder for domestic cattle. The production of large numbers of polished flint axes requiredsubstantial quantities of flint nodules of good mechanical propertiesand sufficient size. Swieciechow flint was ideal because it has uniformmacroscopic structure and moderate fracture toughness (FIGURE 3B; TABLE1), making it less likely to break during preparation. In addition itoccurs as large nodules obtainable by underground mining, allowing themass production of large polished flint axes by the Middle NeolithicFunnel Beaker culture (Balcer 1983: 120; Lech 1982/83: 19, 34; Schild1987: 139,142). These axes are typically 16.1 cm long, and werecarefully polished only along the cutting edge; they were oftendistributed as far as 500 km from the mines (Balcer 1976: 192-4, 1983:179-81; 1988: 70). Banded (Krzemionki) flint axes in the Globular globularresembling a globe.globular hearta spherical cardiac silhouette, usually greatly enlarged and lacking the detailed outline of the right and left atria and apex. Characteristic of pericardial effusion and cardiomyopathy. Amphorae culture(Late Neolithic) The Middle Neolithic Funnel Beaker culture used some polished axesof banded flint as heavy woodworking tools, but banded flint reached thepeak of its popularity among the Late Neolithic Globular Amphoraecommunities, when it was intensively mined in the Krzemionki Opatowskiearea for the production of flint axes (Balcer & Kowalski 1978:129,135-7; Borkowski et al. 1991: 622; Borkowski & Budziszewski1995: 79-80). These axes are rectangular, very carefully made andcompletely polished (Balcer 1988: 84), and are considerably smaller thanthe axes in the Funnel Beaker culture, typical examples being 109 mmlong. The Globular Amphorae people apparently mined banded flint for itsaesthetic qualities rather than its utilitarian functionality (Balcer1983: 223; Balcer & Kowalski 1978: 129, 137; Borkowski et al. 1991:625; Olausson 1983: 13-18). Whereas spotted flint axes were polishedonly along the cutting edge, banded flint axes were completely polished.They have been discovered in numerous graves over the entire areaoccupied by the Globular Amphorae people; at localities as far as 600 kmfrom the mines they occur in quantities as great as places close to thesource. The axes lack any traces of use, modification or repair,indicating that they were not tools but served as symbols of prestige orhad a special religious significance. Banded flint has poor flaking properties because of its highfracture toughness (TABLE 1), although this property makes it the mostsuitable for axe manufacture of the three types of Polish flintconsidered here. It was the least suitable for blade production, andblade cores and blades of banded flint are known only from large flintworkshops producing axe preforms near the mines, and from the few largeNeolithic settlements within 50 km of the mines (Balcer & Kowalski1978). Conclusions The three types of Polish flint studied have differentmicrostructures, and this has caused their distinct flaking properties,as demonstrated by their differing values of fracture toughness. Theflaking properties of the flints, together with their physicalproperties (colour and pattern, presence of cracks, size of availableblocks), determined the tool types manufactured from the flints, andalso the way in which these tools were used by prehistoric communitiesin Poland. Fracture toughness testing, together with microscopic (thinsection) and macroscopic examination, are essential methodological stepsto understanding the flaking properties of artefact lithologies. Thestrategy we have used to study the flaking properties of Polish flintand the differential usage of the flint types is applicable to anymicrocrystalline siliceous artefact material. Acknowledgements. We would like to thank the following people forassistance: T. Ryan, A. Jacka and B. Watts (La Trobe University 1. u/r = unranked2.AsiaWeek is now discontinued. Student lifeDuring the 1970s and 1980s, La Trobe, along with Monash, was considered to have the most politically active student body of any university in Australia. ), A.Lileyman and W. Bamford (Melbourne University), Prof. R. Schild (sampleacquisition; Institute of Archaeology The Institute of Archaeology is an academic department of University College London (UCL), in the United Kingdom. The Institute is located in a separate building at the north end of Gordon Square, Bloomsbury. and Ethnology ethnology(ĕthnŏl`əjē), scientific study of the origin and functioning of human cultures. It is usually considered one of the major branches of cultural anthropology, the other two being anthropological archaeology and , Polish Academy ofScience), Prof. J. Gurba, A. Zakoscielna and J. Libera Libera may refer to: Libera (mythology), a Roman goddess of fertility and wife of Liber Libera (music), a boy choir from London Libera me, a movement of the Requiem (sampleacquisition; Institute of Archaeology, `Maria Curie Curie(kürē`), family of French scientists.Pierre Curie, 1859–1906, scientist, and his wife,Marie Sklodowska Curie, 1867–1934, chemist and physicist, b. Sklodowska'University, Lublin). The comments of three anonymous referees improvedthe manuscript substantially. References BAKELS, C.C. 1987. On the adzes of the northwesternLinearbandkeramik, Analecta an��a��lects? also an��a��lec��tapl.n.Selections from or parts of a literary work or group of works. Often used as a title.[Greek analekta, selected things, from neuter pl. Praehistorica Leidensia 20: 53-85. BALCER, B. 1976. Position and stratigraphy stratigraphy,branch of geology specifically concerned with the arrangement of layered rocks (see stratification). Stratigraphy is based on the law of superposition, which states that in a normal sequence of rock layers the youngest is on top and the oldest on the of flint deposits.Development of exploitation and importance of Swieciechow flint inprehistory prehistory,period of human evolution before writing was invented and records kept. The term was coined by Daniel Wilson in 1851. It is followed by protohistory, the period for which we have some records but must still rely largely on archaeological evidence to , Acta Archaeologica Carpathica 16: 179-99. 1983. Wytworczosc narzedzi krzemiennych w Neolicie Ziem Polskich.Wroclaw: Ossolineum. 1988. The neolithic flint industries in the Vistula and Odrabasins, Przeglad Archeologiczny 35: 49-100. 1995. The relationship between a settlement and flint mines. Apreliminary study of the Eneolithic workshop assemblages from Cmielow(southern Poland), Archaeologia Polona 33: 209-221. BALCER, B. & K. KOWALSKI. 1978. Z badan nad krzemieniempasiastym w pradziejach, Wiadomosci Archeologiczne 43: 127-45. BORDES, F. 1969. Reflections on typology typology/ty��pol��o��gy/ (ti-pol��ah-je) the study of types; the science of classifying, as bacteria according to type. typologythe study of types; the science of classifying, as bacteria according to type. and technique in thePalaeolithic, Arctic Anthropology 6: 1-29. BORKOWSKI, W. & J. BUDZISZEWSKI. 1995. The use of striped flintin prehistory, Archaeologia Polona 33: 71-87. BORKOWSKI, W., W. MIGAL, S. SALACINSKI & M. ZALEWSKI. 1991.Possibilities of investigating Neolithic flint economies as exemplifiedby the banded flint economy, Antiquity 65: 607-27. BUDZlSZEWSKI, J. & R. MICHNIAK. 1984. Z badan nadwystepowaniem, petrograficzna natura oraz prahistoryczna eksploatacjakrzemieni pasiastych w poludniowym skrzydle Niecki Magon-Folwarczysko,Wiadomosci Archeologiczne 49: 151-90. CALLAHAN, E. 1979. The basics of biface knapping in the EasternFluted Point Tradition: a manual for flintknappers and lithic analysts,Archaeology of Eastern North America 7: 1-180. CLARK, J.E. 1987. Politics, prismatic pris��mat��ic? also pris��mat��i��caladj.1. Of, relating to, resembling, or being a prism.2. Formed by refraction of light through a prism. Used of a spectrum of light.3. Brilliantly colored; iridescent. blades, and Mesoamericancivilization, in J.K. Johnson & C.A. Morrow (ed.), The organizationof core technology: 259-84. Boulder (CO): Westview Press. COTTERELL, B. & J. KAMMINGA. 1987. The formation of flakes,American Antiquity 52: 675-708. CRABTREE, D.E. 1968. Mesoamerican polyhedral polyhedral/poly��he��dral/ (-he��dril) having many sides or surfaces. polyhedralhaving many sides or surfaces. cores and prismaticblades, American Antiquity 33: 446-79. DICKSON, F.P. 1981. Australian stone hatchets. A study in designand dynamics. New York New York, state, United StatesNew York,Middle Atlantic state of the United States. It is bordered by Vermont, Massachusetts, Connecticut, and the Atlantic Ocean (E), New Jersey and Pennsylvania (S), Lakes Erie and Ontario and the Canadian province of (NY): Academic Press. DOMANSKI, M. & J.A. WEBB. 1992. Effect of heat treatment onsiliceous rocks used in prehistoric lithic technology, Journal ofArchaeological Science 19: 601-14. DOMANSKI, M., J.A. WEBB & J. BOLAND. 1994. Mechanicalproperties of stone artefact materials and the effect of heat treatment,Archaeometry 36: 177-208. FARMER, I.W. 1968. Engineering properties of rocks. London: Spoon& Spoon. FENTON, M.B. 1984. The nature and sources of the manufacture ofScottish battle axes and axe-hammers, Proceedings of the PrehistoricSociety 50: 217-43. HAYDEN, B. 1987. From chopper to celt: the evolution ofresharpening techniques, Lithic Technology 16: 33-43. KIRCHHOF, G., W. POMPE & H.A. BAHR BAHR Business and Human Rights (university class). 1982. Structure dependenceof thermally induced microcracking in porcelain studied by acousticemission, Journal of Materials Science 17: 2809-16. KOROBKOVA, G.F. 1978. Drevnejshie zhatvennye orudiia i ikhproizvoditiel'nost', Sovetskaia Arkheologiia 4: 36-52. KOZLOWSKI, J.K. & S.K. KOZLOWSKI. 1977. Epoka kamienia naZiemiach Polskich. Warszawa: Panstwowe Wydawnictwa Naukowe. LAWN, B.R. & T.R. WILSHAW. 1975. Fracture of brittle solids.Cambridge: Cambridge University Press Cambridge University Press (known colloquially as CUP) is a publisher given a Royal Charter by Henry VIII in 1534, and one of the two privileged presses (the other being Oxford University Press). . LECH, J. 1981. Flint mining among the early farming communities ofcentral Europe, Przeglad Archeologiczny 28: 5-55. 1982/1983. Flint work of the early farmers. Productive trends incentral European chipping industries from 4500-1200 b.c., ActaArchaeologica Carpathica 22: 5-63. MATHIEU, J.R. & D.A. MEYER. 1997. Comparing axe heads of stone,bronze and steel: studies in experimental archaeology, Journal of FieldArchaeology 24: 333-51. MCBRYDE, I. 1978. Wil-im-ee Moor-ing! Or, where do axes come from?,in J. Specht & P.J. White (ed.), Trade and exchange in Oceania andAustralia, Mankind 11: 354-82. OLAUSSON, D.S. 1983. Lithic technological analysis of thin-buttedflint axe, Acta Archaeologica 53. PRINKE, A. & J. SKOCZYLAS. 1980. Stone raw material economy inthe Neolithic of the Polish lowlands, Przegla d Archeologiczny 27:53-85. RICE, R.W., S.W. FREIMAN & J.J. MECHOLSKY, JR. 1980. Thedevelopment of strength-controlled fracture energy on the flaw-size tograin size ratio, Journal of the American Ceramic Society 63: 129-36. SCHILD, R. 1976. Flint mining and trade in Polish prehistory asseen from the perspective of the chocolate flint of central Poland. Asecond approach, Acta Archaeologica Carpathica 16: 147-77. 1984. Terminal Paleolithic of the North European Plain: a review oflost chances, potential, and hopes, Advances in World Archaeology 3:193-272. 1987. The exploitation of chocolate flint in central Poland, in G.de G. Sieveking & M.H. Newcomer (ed.), The human uses of flint andchert chert:see flint. : 147-77. Cambridge: Cambridge University Press. 1996. The North European Plain and Eastern Sub-Balticum between12,700 and 8,000 BP, in L.G. Straus, B.V. Eriksen, J.M. Erlandson &D.R. Yesner (ed.), Humans at the end of the Ice Age: the archaeology ofthe Pleistocene-Holocene transition: 129-57. New York (NY): Plenum. WHITTAKER, B.N., R.N. SINGH & G. SUN. 1992. Rock fracturemechanics. Principles, design and application. Amsterdam: Elsevier. MARIAN DOMANSKI & JOHN A. WEBB, Department of Earth Sciences,La Trobe University, Victoria 3083, Australia. john.webb@latrobe.edu au Received 3 December 1999, accepted 8 February 2000, revised 26 July2000.