Draft of 7-17-02
Variously known as "cupstones," "anvil stones," "pitted
cobbles" and "nutting stones," among other names, these roughly discoidal
or amorphous groundstone artifacts are among the most common lithic remains
of Native American culture, especially in the Midwest, in Early Archaic
contexts. They have received little study, perhaps because edged tools
and weapons have more intrinsic interest to collectors, but closer study
of them might reveal something of domestic practices and toolmaking technology.
The use of these items is unknown -- although the
ad hoc terminology implies function(s). Professor Betsy Delmonico of Truman
State University has pointed out that very similar artifacts are known
from the Indian subcontinent, often incorporated into clearly decorative
and cultic objects, and the phenomenon has been observed in Celtic Europe
and even in Australia and Israel. Some insist the items are "false" artifacts,
that is, their form results from natural processes rather than human activity.
However, no one has yet described processes that might both produce such
effects and also explain the distribution of the effects and the objects.
Certainly air-bubbles in stone, broken open and eroded, could produce some
of these phenomena. The objects are familiar in Illinois, Ohio, Indiana,
Arkansas, Kentucky, Tennessee, the Carolinas, Alabama and Mississippi,
and occur elsewhere as well. Often they have been collected as oddities,
and are found in residential rock-gardens. All of the stones pictured here
were recovered from Adair County MO by Adam Brooke Davis, from private
land, with permission, and none were in association with burials or sites
of archaeological value.
When not carried by natural forces into creekbeds,
these objects are frequently surface-found on ridge-lines and at apparently
random sites in the woods, frequently near streams and rock-shelters, suggesting
a possible link to hunting, or with the combined activities of a seasonal
hunting/gathering camp. Excavated specimens are associated with food-processing,
including potsherds and food-remains. The author has found several near
the remains of small and single-use fires, but the number of sites is insufficient
to make a compelling case for the association. If used for mast-processing,
one would expect the objects to be associated with relatively long-term
occupation-sites. A camp-midden on the Chattahoochee River (http://www.cr.nps.gov/seac/benning-book/ch04.htm)
yielded twelve specimens, along with grinding slabs and the hulls of acorns
and hickory nuts, which were known in historic times to be prepared either
as gruel or used to thicken soups. The pits may be adaptations for additional
uses to implements primarily classifiable as other types, for example manos
and metates. Interestingly, the only test using contemporary immunological
analysis, carried out on a specimen from California, gave a positive result
for trout residue alone (http://www.californiaprehistory.com/reports01/rep0015.html#anchorapp).
Specimens found near Arkansas petroglyphs lead George Sabo III and Deborah
Rowland Sabo of the Arkansas Archeological Survey to suggest the impressions
were used to grind pigments for coloring rock art (http://rockart.uark.edu/whatisrockart.html).
Two uses not yet discussed include making fire by
the bow and drill method, in which case a stone might have been used to
anchor the upper end of the shaft, while a string, held taut with a bow
and wrapped around the shaft, would provide rotary motion to create friction
on a slab of wood on top of which tinder had been piled. Amateurish experiments
have failed to demonstrate the principle, but the author makes no claim
to fire-making skill under any circumstances. A few specimens show fire-marking,
which may indicate that they served as the base-socket for the fire-drill,
with tinder piled around the rotating shaft -- or they may have found their
way simply and accidentally into a fire. A much more comprehensive study,
carefully correlating the closely observed features of these objects, is
Another possibility might be that the impressions
provided a socket to hold the butt end of a shaft steady during peeling
and straightening. The author has tested this hypothesis with a shaft-straightener
or abrader found near one of the cupstones--
and the method is at least practical. Larger indentations
might have been used to steady spear-shafts. Multiple impressions might
suggest communal, industrial manufacture of implements and weapons. Stones
with multiple impressions of similar size, yet which would not be simultaneously
accessible are difficult to explain. Most of the objects are of a size
to be held in the hand, some as small as a walnut, but the writer has discovered
one, left in situ in a streambed, roughly a cubic meter of black
rock entirely unlike any surrounding boulders, and weighing many hundreds
of pounds. This is likely to be a cultic object of the sort discussed by
U-MN anthropologist Kevin
L. Callahan: Petroglyph Boulders and Sacred Stones of the
Upper Midwest (http://www.geocities.com/Athens/Acropolis/5579/midwestboulders.html
-- the site includes a map of the distribution of these boulders throughout
The pattern, size and number of concavities is not
predictable, nor is material -- impressions are found in soft sandstone
and hard granite. Cupstones may exhibit a mixture of large and small indentations,
perhaps indicating multiple uses over a considerable span of time. Indentations
range from barely visible (1/16" -- much too small for any use thus far
hypothesized) to 6". In most cases the circumference of the impression
will be roughly equal to the depth. Examination under magnification suggests
the impressions were at least in some cases formed by rotary grinding.
Typical impressions are of the simple pit type, though some cavities have
been excavated to produce an opened-sphere type of pocket, by means and
for reasons unknown -- as in the specimen immediately below (4.5" x 4"x3";
opening shown is .75" across, widening to 1" within). The object has another
impression of equal width but only .25" deep. It also shows signs of use
on two faces for grinding against a slab, the scratches indicating both
linear and rotary motions.
A. approx. 13.5" x 8" x 6", 28 lbs., 32 impressions
of various depth, ranging from 1/16" to1/2"
-- shows an incised trench leading to or from the
cavity (1.75"), suggesting that some sort of fluid was channeled into or
out of the cavity. Incised lines are not uncommon; a spedimen recovered
from the Big Eddy site had over 300 such lines, perhaps for drainage and
drying of wet material.
D. A large, irregular block of weathered sandstone,
very subject to fracture (though observation of edge-wear indicates none
of the breaks are modern), 7" x 7" x 4", 10 lbs. The dark spots to
the left and right are connected in a sort of tunnel of varying width,
incorporating a bend of about 100 degrees (the central dark spot is a trick
of the light). The author speculates that it may have been used as a weight,
perhaps to suspend provisions from a tree limb, out of reach of animals.
It would make a practical anchor, though it was not found in a position
likely ever to have been near water. The edges of the openings may show
some slight degree of wear consistent with cordage. Below, the same stone
shows a cluster of much smaller indentations (each about 1/4"). There is
no reason but co-occurrence to assume a functional connection between the
larger and smaller indentations.
E. This object, broken on the side away from the camera
in relatively recent times from some larger body (unrecovered), could well
have been used for grinding nuts or pigments -- the aperture is 1 7/8"
wide and a full inch in depth. It might well be a mortar.
However, the breakage did not necessarily end the
object's useful life. The specimen below (G) is similarly broken at some
layer of material weakness from a larger body, and on the smooth, upper
side, there is a single impression. But on the opposite side, the rough
portion originally inside the stone, later activity has added a second
cavity, connected at a tangent with the first so as to make some sort of
straining activity possible (shown a second time with contrast enhanced);
a very small pit (1/8") is visible in the lower left quadrant, and a yet
smaller one (1/32") about 1/4" inch to the right of the largest hole, in
a line with the other two:
Both of the large indentations are of the spheroid
type. On the side away from the camera, the rim of the single large opening
is worn, and within the worn orbit are a number of pits so small as to
be visible only under oblique light, and near the edge of the stone, another
pit, drilled from a different direction, of 1/4".
Conclusion: function and terminology
The most likely interpretation seems that these artifacts
represent a single technique of shaping or adapting stone for multiple
purposes, some unguessed (for instance, the function of the smallest pits)
and that the objects could be used by single or multiple individuals over
long periods of time, and for various purposes. Indeed, the apparent randomness
of their distribution may indicate that they were left lying as modified
natural resources, whether with benevolent intent or because they did not
represent a sufficient investment of time and labor to justify transporting
them ("opportunistic" tools). More simply, perhaps the users intended to
return to the same area during the next year's mast-gathering period. The
now traditional term "nutting stone" may be justified, as may "straightening
stone" or "shaft-anchor" within a larger class we might call "poculoliths,"
(<L. poculus, "small pocket," "cup"). While an equivalent to
"pitted stone," the proposed term has the advantage of wider comprehensibility
among international scholars as the worldwide distribution of the form
becomes increasingly evident.
Links and information on poculoliths:
Publications and scholarship:
A professional study of coastal California specimens: http://www.californiaprehistory.com/reports01/rep0015.html
Fountain. "Cupped or Pitted Stones" The Archaeological Society of
New Jersey Bulletin #52 1997 (113 pp.) — $10.00 at http://home.earthlink.net/~glattanzi/asnj/back-issues.html
Peacock, Evan 1989 "Microdebitage from Cached Pitted Stones."
Pyle, Robert L., "Mysterious Cupstones: A Secret of the Past," Wonderful
West Virginia, July 1985
Ritchie, William A. Hammerstones, Anvils and Certain Pitted Stones
(1929). Rpt. From Coyote Press (http://www.coyotepress.com/page27.html)
Watts, Steve. "The Nutting Stone" The Bulletin
of Primitive Technology Spring 1997 (The Society of Primitive Technology:
SPT Bulletin #13: Foods and Cooking). Available at http://www.primitive.org/backissues.htm
J. Witthoft. "Pitted Stones and Cup-Shaped Markings."
of the Archaeological Society of Maryland. Volume 5, #2 (September
Images and commentary on the web:
A specimen found in Caithness, Scotland: http://www.caithness.org/caithnessfieldclub/outings/broubsteraug2000/
Discussion of a find near Jerusalem, with commentary on the possibility -- highly controversial -- that chimpanzees also engage in such activity, maintaining toolkits of suitable nutting stones over time.
See also Goren-Inbar, N., et al. 2002.
"Nuts, nut cracking, and pitted stones at Gesher Benot, Ya'aqov, Israel."
of the National Academy of Sciences 99(Feb. 19):2455-2460. Abstract
available at http://www.pnas.org/cgi/content/abstract/99/4/2455.
Examples of central Texas stones associated with pestles. Dealer/owner believes the pattern of impressions on some of these stones is explained by gripping-points for fingers and thumb.
An impressive multi-pitted specimen from Indiana.
Diagram of a Connecticut specimen.
"In many parts of the world this type of artifact
is usually associated with fall occupations."
Photo of a Massachusetts specimen: http://www.memorialhall.mass.edu/collection/itempage.jsp?itemid=5243&img=0
An unusual, squared specimen from Madison Co. MS:http://home.att.net/~wjvd3/artpage25.html#Nutting stone