University of Minnesota
Department of Anthropology


Making and Using Projectile Points

In looking at your projectile points, it is helpful to know how they were made and how their appearance has been changed though use and resharpening. Since Minnesota‚Äôs stone projectile points were used with three different kinds of delivery systems, it is useful to know, too, which of your points were used with which kind of delivery system —spear, atlatl, or bow and arrow. Each of these systems has its own aerodynamic requirements, which affect the size and shape of a point.

Projectile Point Manufacture

Projectile points are formed by a series of flintknapping activities intended to reduce flakable stone from a larger flake or core into a smaller completed tool. Projectile points are best viewed within the context of manufacturing, maintaining, rejuvenating, and recycling a variety of chipped stone tools.

Like all chipped stone tools, projectile points begin with flakable raw materials. Chipped stone raw materials have certain qualities, foremost of which is the characteristic of being conchoidally fractured. The classic example of a conchoidal fracture occurs when a BB hits a glass window, producing a Hertzian cone. Stone that fractures conchoidally is homogeneous, brittle, and elastic. The list of materials used in the production of stone tools in Minnesota is long (see Lithic Raw Materials in Minnesota: A Summary). Heat treating most stone types makes them easier to flake, perhaps by making the stone more homogeneous and creating micro fractures. In the process, the tensile strength of the stone is reduced by as much as one-half.

Reduction Systems

There are two main reduction systems of flaking stone into projectile points in Minnesota: flake-core and core-biface. These systems have been proposed by numerous archaeologists who try not only to replicate the actual projectile points and other tools found at the numerous campsites, villages, towns, and quarries throughout North America, but also the by-products or debris from these activities. Flintknapping results in large quantities of usable and unusable flakes, the latter termed chipped stone debris or debitage.

The most common approach used by past Native Americans in Minnesota is the flake-core system whereby flakes are struck from cores. This system can be subdivided into three separate subsystems depending on the shape of the core: biface-core, conical flake core, and multidirectional flake core. The biface-core subsystem requires relatively large pieces of raw material for the production of a core flake blank which is shaped into a bifacial flake core (Reduction Sequence A). As the biface is reduced, flake blanks are produced which in turn serve as point blanks and preforms for finished points. Additional maintenance and rejuvenation activities eventually result in a discarded point. Archaeologists sometimes assign these somewhat arbitrary stages a series of numbers (Callahan 1996). Reduction systems can also be broken down into primary, secondary, and tertiary stages (not to be confused with flaking debris of the same names). Flake blanks produced from a conical flake core (i.e., a core with a single platform from which flakes are removed in one direction) are more rare in Minnesota since few exhausted cores of this type have been recovered. Although the flake blanks have a different morphology than those produced from a bifacial core, the two flake blanks are impossible to distinguish once they have been made into completed points. Multidirectional cores, those that have flakes removed from a number of platforms and directions, are more common in Minnesota than conical cores (Reduction Sequence C). Heat treatment probably occurred early in the reduction sequence of all of these systems, probably at the biface core stage or the flake blank stage.

reduction systems

The core-biface reduction system involves removing flakes from a core with the intention to create a completed bifacial tool such as a projectile point from the core itself rather than have it serve only as a source of flake blanks (Reduction Sequence B). Unlike projectile points made from flake blanks that frequently retain their original detachment ventral flake scar, points made from the reduction of a core do not possess this characteristic.

Reduction Techniques

There are three major techniques used in reducing stone into its desirable shape: hard hammer, soft hammer, and pressure flaking. Hard hammer direct percussion is usually involved in the early reduction stages and consists of striking the stone to be flaked with a hand-held hammerstone. Some flintknappers use hammerstones up until the time of final thinning and edging of a projectile point by pressure flaking. Hammerstones are usually hand-sized, relatively flat cobbles of medium-grained tough stone, such as basalt or quartzite, that can withstand numerous direct blows to the more brittle stone being flaked. The actual working end of a hammerstone is along its more rounded or convex edges. Hard hammer percussion usually is done on platforms or edges of rock with angles less than 90 degrees. In cases where the raw material to be flaked is relatively small in size and/or has no edges less than 90 degrees to flake (e.g., a cobble or pebble), bipolar percussion is frequently used to split the material by placing it on a large rock and striking it with a hammerstone.

Soft hammer direct percussion involves striking the stone with a tool made from some object less hard than stone. The most common types of soft hammer materials include antler, bone, and wood percussors, billets, or batons. Although some flintknappers feel that soft hammer percussion is the most effective technique for making bifaces or point blanks (Whittaker 1994:178), hard hammer percussion can also be effectively employed. Another knapping technique is indirect percussion, where a punch made from antler, wood, or other material is placed against the stone and hit with a hammerstone or baton. These flaking techniques are similar in the sense that they require striking platforms less than 90 degrees and considerable edge or platform preparation prior to flaking.

Pressure flaking involves the removal of flakes by placing a pointed flaking tool made from wood, bone, or antler, or a copper rod, against a stone and applying force. When manufacturing projectile points, this technique is most commonly used in the final bifacial thinning and shaping of a point and the creation of any notches or flutes. Again, platform preparation is important in controlling flaking at this stage (Whittaker 1994:140-147).

Maintenance, Rejuvenation, and Recycling

The major criterion used by archaeologists and amateurs alike in assigning most projectile points to types is their form. Other criteria include technological characteristics, such as basal and haft grinding and flaking style. As points are used, they are frequently fractured, resulting in their discard or rejuvenation. Occasionally, they are recycled into other tool forms. Maintenance or rejuvenation frequently results in points that are shorter than their newly completed counterparts while retaining their basic form (Hoffman 1985). Some archaeologists argue that some projectile points have been so altered in form during rejuvenation that the early and late phases in their life cycle are unwittingly assigned to different point types (Flenniken 1985; Flenniken and Wilke 1989; Flenniken and Raymond 1986; Thomas 1986). Although it is beyond the scope of this brief discussion, everyone should be aware of the ways projectile points can change over their life cycles so that point typologies, like the one presented in this book, do not make temporal distinctions between forms where they do not exist.

Projectile Point Use

Most projectile points are believed to have been hafted to wooden shafts by sinew, cordage, and/or naturally occurring adhesives. These weapon systems were used to hunt game. In some cases, projectile points also served as cutting tools (Ahler 1971) or ceremonial objects sometimes included with human burials. The thrusting spear tipped with a chipped stone point was one of the earliest weapons. In North America, it was used on mammoth, mastodon, bison, and other large mammals at close quarters once the animals became trapped or incapacitated. Thrusting spears were probably also used in later periods as weapons to dispatch wounded animals no longer able to elude their human predators. Throwing spears or darts were tipped with points on removable foreshafts. A throwing stick or atlatl with a hook on one end to hold the shaft provided an extension to the arm for more force. Once embedded in the animal, the foreshaft separated from the main shaft, continuing to aggravate and draw blood from the animal. This may have occurred over a number of days until the animal either died or could be approached for the final kill. With the advent of the bow-and-arrow about 1500 years ago, points became relatively small, thin, and light. The emphasis was on speed to penetrate the vital organs of large and small mammals alike.