A French term, used directly in English publications, that has
been defined as follows: The intentional action of breaking a
block of raw material (hard rock) in order to use the products
(flakes, blades, bladelets) as they are, or to convert these into
tools by retouch. ´Debitage´ also comprises the results
of this action (Tixier 1974,
14).
It has also been defined as:
Residual lithic material resulting from tool manufacture. Useful
to determine techniques and for showing technological traits.
Represents intentional and unintentional breakage of artifacts
either through manufacture or function. Debitage flakes usually
represent the various stages of progress of the raw material from
the original form to the finished stage. (Crabtree
1982., 32).
Blank
Blank is a term used to describe a usable piece of lithic material
of adequate size and form for making a lithic artifact, such as
unmodified flakes of a size larger than the proposed artifact,
bearing little or no waste material, and suitable for assorted
lithic artifact styles. The shape or form of the final product
is not disclosed in the blank (Crabtree
1982 27). It is possible to have a number of blanks in the
early stages in the manufacturing process before the stage of
being converted to a preform is reached. index
Preform
A preform is the term used to denote a piece in the initial shaping
stages for the formation of a tool. A preform is an unfinished,
unused form of the proposed artifact. It is larger than, and without
the refinement of, the completed tool. It is thick, with deep
bulbar scars, has irregular edges, and no means of hafting. Generally
made by direct percussion. Not to be confused with a blank (Crabtree 1982, 49). index
Debris are the waste
materials such as are found in quarrying or mining waste, which
have little or no definitive characteristics (Crabtree
1982, 32). Debris is also commonly used to describe materials
from a site which are considered to be waste materials from a
production process. For example, materials found in a dump could
be considered to be debris. index
Detritus is the waste
of disintegrated rocks, such as accumulated waste at a natural
exposure, having little or no diagnostic value (Crabtree
1982, 32). An accumulation or the remains of broken and natural
(i.e. unworked) rock. This is not a term normally used in connection
with humanly struck material. index
Any piece of stone removed from a larger mass by the application
of force, either intentionally, accidentally, or by nature. A
portion of isotropic (homogenous) material having a striking platform
and bulb of force (or bulb of percussion) at the proximal end.
The flake may be of any size or dimension, depending on which
technique was used for detachment (Crabtree
1982, 36).
A fragment of hard rock intentionally detached from:
- a core in the course of preparing or rejuvenating it: which
is then called a core preparation or core rejuvenation flake
- a core with the intention of later turning it into a tool by
retouch it: a
- a tool in the course of shaping it by retouch: then called a
retouched flake (Crabtree 1982.
14).
Flakes have two faces: a dorsal and a ventral. The dorsal surface
can be partly or totally covered by cortex, but normally shows
the scars from removals which were made before this flake was
removed from the core. The ventral surface contains only the features
related to the detachment of this particular flake.
Flakes also have two ends: a proximal and a distal. The proximal
end contains the features of the point of impact and detachment
or the point of percussion. Opposite this is the distal end.
Flakes and blades are oriented with the dorsal surface up and
the proximal end (which can only be determined from the ventral
surface) down. The left and right edges of the artifact are set
from this orientation and remain as such, regardless of which
way the piece is turned.
It is common for the dorsal surface to bear traces of negative
scars from previous removals. These are called dorsal scars and
are separated by a ridge which is created at the junction between
two removals.
The ventral surface contains virtually all information pertaining
to the detachment of this particular artifact from the core. The
small section of platform retained from the core is now called
the butt. The main surface of this face shows a swelling, or bulb,
arising from a point just below the striking platform or point
of percussion. Other features include concentric ripples, or lines
of force, which show the direction of percussion, and irregular
straight fissures, both of which radiate from the point of percussion.
A particularly important feature which can occur on the ventral
surface is the bulbar scar, or érrailure. This is a small
negative (concave) scar of irregular shape on the bulb marking
the place from which a small chip springs away at fracture. As
this feature is very common on humanly struck materials and is
rare on naturally produced flakes it is a useful guideline to
use when examining stray specimens which could be natural (see
Patterson 1983, 300).
A chip is a small
flake. The exact measurable limits for this artifact vary, depending
on the typology in use in the area of investigation, but are normally
less than 20 mm. A chip is considered to be too small to have
been selected as a possible blank for tool production. index
Blades are flakes with
more or less parallel lateral edges which, when complete, would
have been at least twice as long as wide (Owen
1982, 2).
Specialized flake with parallel or sub-parallel lateral edges;
the length is equal to, or more than, twice the width. Cross sections
are plano convex, triangulate, sub triangulate, rectangular, or
trapezoidal. Some have more than two crests or ridges. Associated
with prepared cores and blade technique; not a random flake (Crabtree 1982,, 16).
A blade is technically defined as any flake that is more than
twice as long as it is wide, with more or less parallel edges.
Whittaker 1994, 33
Blades may be produced with hard hammer technique, but most often
soft hammer and indirect percussion is used. The exact measurable
limits for a blade vary widely. These are normally defined by
whichever typology is currently in use in the area of investigation.
There is general agreement on the length/width ratio of > 2,
however, the maximum width can be set anywhere between 8mm (Helskog et al 1976.), 10mm (Hahn 1977, 44 and Hahn
1982, 26-27), 11mm (Taylor
1962, 425-426), and 12mm (Tixier
1974 7). There are normally no maximum length measurements
for blades.
Blades are oriented exactly the same as flakes, with the bulb
of percussion down and the dorsal surface up.
bladelet
Simply stated microblades are small blades (Owen
1982, 2). These artifacts, which are also called bladelets,
suffer the same problems regarding varying size restrictions as
blades.
The minimum width limit for a blade is the maximum acceptable
width for a bladelet or microblade. This is between 8-12mm, depending
on the typology in use. However, in some instances the maximum
permissible length for this group has also been subject to discussion
(see Tixier 1974 , 7-8).
N.B. in Norway a blade is a bladelet (mikroflekker) if it is less
than 8mm. in width. The standard maximum width for a bladelet
is 12 mm.
knapping fragment
A knapping fragment a product of the knapping process which has
identifiable negative scars and is irregular in shape. The distinguishing
feature is that it is impossible to determine the final plane
of detachment from the core (i.e. its ventral surface). Terms
such as splinter or chunk are also used to describe this artifact,
however, as these are general descriptions, and are used in other
connections, their use is not recommended.
A knapping fragment is not a section of an artifact, such as a
flake, which still has an identifiable dorsal and ventral surface
even when it is incomplete or fragmentary. This would be called
a broken flake as opposed to a knapping fragment.
platform rejuvenation
flake
A platform rejuvenation tablet (or core rejuvenation flake) is
the result of the process by which the exhausted or ruined core
platform would be removed as a tabular flake thereby establishing
a new platform (Crabtree 1982,,
50). (Also see Owen 1982,
219). The removals around part or all of the edge of these artifacts
often causes them to be mistaken for scrapers. It should be noted
that the origin of these abrupt negative scars is from the dorsal
surface and has been executed before the piece was removed from
the core.
flake from a polished
axe
A flake from a polished axe is a flake which has retained a portion
of the surface of an intentionally polished tool on part or all
of its dorsal surface. These flakes can be the result of damage
to a polished axe or can occur from the reduction of the damaged
tool (for example, when it is used as a core to extract the remaining
usable raw material). When examining flakes detached from a polished
tool it is imperative to check that the polish is intentional
(i.e. smooth, flat, and with characteristic polish striations)
and is not simply the gloss from agents such as plant deposits
or the natural weathered outer surfaces of the raw material. These
forms of gloss are distinguishable in that the supposed ´polish´
often fills surface concavities (something that is not possible
with intentional polish). index
crested blade (click
here to see sequence)
A straight ridge is necessary to guide the removal of the first
blade from a core. If a natural ridge is not present, one can
be produced by flaking on the core face. Such a ridge is created
by extensive flaking perpendicular to the length axis of the core.
The removal of this primary ridge blade, or crested blade, leaves
straight scars on the core face which serve as guides for further
blades (see Owen 1982, 3).
Crested blades have also been described as follows:
First blade removed from a core. Bears bi-directional flake scars
on the dorsal surface, the result of the worker preparing a ridge
to guide the blade (Crabtree 1982,,
41).
Parts of debitage
Parts are broken or fragmentary flakes and blades which can be
classified into three parts: the proximal part, medial part (or
middle) and distal part sections.
The proximal part is the proximal end of a flake or a blade
and is the section containing the bulbar end of the fragment,
or the part that received the blow which detached it from the
core. This often includes all or parts of the butt, bulb of percussion
and the initial lines of force or ripples radiating from the point
of impact.
The medial part is the medial, or middle, section of a
flake or a blade can be in many fragments or parts. These fragments
can be oriented by identifying the direction of percussion by
the lines of force, or the ripples, and the fissures on the ventral
surface.
The distal part is the distal portion of a flake or blade
is opposite to the proximal, or bulbar section, and is the end
of a piece. It can terminate in a number of ways (see feathering,
step and snap fracture,
hinge and plunge).
It is possible to correctly orient these fragments from the ventral
surface by identifying the direction of percussion, by the lines
of force, or ripples and by the fissures.
