Ooyurka - unique T-shaped stone tool of the Wet
What is an Ooyurka?
It is an Ooyurka if it is found in the far north Queensland
region. It is a stone tool unique to the rainforest region. An
Ooyurka needs to have some kind of shoulder waisting, the orientation of
the face has to be perpendicular, and there needs to be some residue of
polish, or organic material in the working face. There is a narrowness of
the working face and it should be a slate (there are some schists, and 2
basalt ones found but the rest are argillaceous or spotted hornsfels
slate). The working face may be convex, concave or flat.
What were Ooyurkas used for?
80-90% of Ooyurkas have been discovered. them have been dug up
by ploughs while planting Sugar Cane. None have been carbon dated.
It is suggested that they are no older then 5,000 year old(but there is no
solid evidence to support this claim), yet no one from the Dyirbal or
Yidin clans know how to use the Ooyurka nor know what they are for.
Also, Ooyurka is not a word from the language of these two rainforest
Kennedy in 1949 suggested the stones were used to smooth the modern
Aboriginal tools. It appears the Rainforest Aboriginal made wooden swords.
During the wet season, the people of the rainforest were quite
sedentary and would spend their time based in the one location. They built
substantial large huts up to 9m long and 3m high that connected to other
large huts via internal doorways.
The case against them being used as "nutcrackers"
When the green cicada called they knew the bush turkey would be laying
it's eggs and the mountain rainforest "nut" trees would be bearing fruit.
They went to areas in the rainforest where there were nut trees, often
farmed by removing unwanted saplings), harvest the nuts and storing them
in the ground under "climate controlled" conditions (damp pits) until they
were ready for use.
There were four kinds of nuts generally harvested (listed least toxic to
most toxic) Black
Walnut(Endiandra palmerstonii) --> Hairy Walnut ( Endiandra insignis
) --> Black Bean (Castanospermum australe) --> Beilschmieda
bancroftii (yellow walnut)
The black walnut (due to it's appeal to local animals) needed to be
harvested by climbing
up in the rainforest canopy using lawyer vine
Other sources include: Kuranda quandong (Elaeocarpus bancroftii), Black
Pine(Sundacarpus amarus), Macadamia whelani (macadamia nut).
It is said that the ooyurka was left behind in their shelters and used by
others or used by themselves when they returned back to the area at
commencement of the next wet so the tools was used primarily during the "wet
They became more mobile and got into hunting once the drier season
started. This could entail a journey from the mountains to the coast where
they built substantial , complex fish traps along the river flatlands.
These fish traps needed to be re-constructed on an annual basis to to
Nuts are very hard and the working edge of the ooyurka was often less than
15mm wide and this is less than these nuts, so often the working edge
would bounce/slide off the nut and hit the anvil surface, often causing
damage to the (pretty soft) edge of the Ooyurka. These kind of slates have
a Mohs scale rating of 3 at the hardest! None of the original ooyurkas
showed this kind of damage.
Besides the rainforest people had excellent two piece nutcrackers. - a
flat rock with incised pits, just the size of the nuts and a hefty hammer
Geology and surface features
Ooyurkas are made from
coarse Crystalline Basalt,
(The choice of these rock types is significant and will be covered
in detail as this web site develops)
weighed between 50g and 1060g with the mean weight being
majority were between 100-300gms.
65% had a flat working surface,
working surface highly polished from use through movement along the
23% concave and 12% convex.
striations coming over the shoulders and into a V pattern at the
42% show signs of initial hammer dressing
25% show signs of surface grinding (using a sand medium as an
abrasive) particularly around the shoulders
grinding process was used to excavate the face.in addition to the
sand polishing (outcrops of sandpaper-like coarse quartzite found in
the local metamorphics)
no evidence that the ooyurka was a hinged tool and that one end of
it was placed in a socket.
lacking evidence of specific tool grinding sites where grooves show
that grinding was practised for a very long time on each site.
Wet season use.
Ooyurka could also be used to pare bark away from stems or tree
trunks to make rope, twine, thread for bark blankets from the inner bark
of the Red Tulip Oak(Argyrodendron sp.)
and could have been used in wooden tool making from spear shafts to,
boomerangs to shields. Most likely nothing to do with food at all.
(April 2017 webmaster pers comm.with traditional owner)
(All ooyurka held by the webmaster clearly fit best in the right
hand only) Female use Ooyurka
(The following is an abridged version of a paper about starchy residues on
Grindstones from Australia are known to be used for a variety of functions
including plant processing, preparation of ochre and also for the
maceration of foods such as lizards and cats (Gould 1980; Mitchell 1848).
Grindstones are common in the tropical rainforests of far North Queensland
and have often been found by farmers ploughing paddocks (Woolston &
One particular type of grindstone, referred to as the morah stone, comes
from a well defined area from Tully in the south, to Cairns in the north
and west to the Ravenshoe area on the Atherton Tablelands (Woolston and
Morah stones (sometimes referred to as graters by locals) are made
from grey slate, a soft and brittle stone that is available locally.
They are distinguished from other grindstones by a series of incised
grooves running perpendicular to the axis of the artefact.
Maisie Barlow, a Jirrbal elder from Ravenshoe, relates that the incised
grooves were made with quartz pieces, though bone points have also been
suggested as tools for this purpose.
(Webmasters personal opinion is that the morah stones were the ideal
surface with which to remove and collect the thin flesh of the
ubiquitous and long fruiting varieties of widely available quandong.
In addition there are other fruits in the rainforest with large seeds
surrounded by a thin but edible layer of flesh that would be suitable.
You simple roll the ripe quandong across the surface with the palm of
your hand and the skin and flesh come off onto the surface and into the
The flat morah could also be used as a "plate" to keep crushed
nuts out of the dirt - hence the starchy residue.
As with the Ooyurka there is no reason other than "Western thinking" to
think that a stone tool requiring great labour to produce would be
limited to a single purpose.)
Morah stones occur in a region where the processing of toxic starchy
plants is common (see Pedley 1993), and their use may be tied to the
extended processing of these economically important foods.
Morah stones are described by an unidentified Nutjen (Ngatjin) woman to be
used in a ‘rolling crushing’ motion rather than grinding (Woolston &
Colliver 1973). These were said to be used to crush zamia and walnuts.
The upper stones are known as ‘moogi’, the name given by the same
informant describing the use of morahs referred to by Woolston and
Colliver (1973:118) and are documented in the Australian and Queensland
Museum collections. Moogi are usually a granite raw material, which are much harder
than the slate of the morah stones. Horsfall (1987:209-211) measured over
58 morahs (22 whole and 36 fragments) and found that none of them were
more than 65 mm thick, though in this study the thickness of the
grindstones did not exceed 30 mm.
The thickness of the grinding stones is argued to be a function of the
local slate raw material, which tends to cleave into relatively thin
plates. Some of the morahs examined by Horsfall had incised grooves on
both surfaces but most had incisions on only one surface. Used surfaces
tend to be flat to concave, consistent with documented grindstone wear
patterns (see Field & Fullagar 1998; Smith 1985).
Very few complete morahs are known and the largest morah we have observed
was nearly 50 cm in length, and while broken, was mostly complete and in a
private collection near Innisfail. Morahs are known from the
Combined with overall morphology and related use-wear studies, the
function of morah stones will be discussed. Unused surfaces were smooth
and featureless and not incised.
Ethnographic observations of the processing of starchy foods indicate that
all surfaces of the grindstone will generally become covered in starchy
material and any flaws, or incised surfaces are likely to act as residue
Combined with residue studies and morphological analyses, use-wear
analysis is an informative adjunct for identifying patterns of wear and
probable tasks (Fullagar et al. 1996).
Of the eleven morahs that were sampled for this analysis, one grindstone
yielded no starch at all, while the remainder produced variable amounts of
starch. Some starch grains are very distinctive and require very few
grains in order to estimate the likely species of origin - for example
tubers and some grasses - however for the species likely to be represented
here such as Cycas media and Beilschmieda bancroftii (yellow
walnut) the overlap in size and similarities in morphology demand a
larger sample for examination.
except perhaps for far North Queensland rainforests where the morah or
incised grinding stone is a common feature of the archaeological record
(Cosgrove 1996; Cosgrove et al. 2007).
Combined with the morphology and associated use-wear patterns described
below, there is compelling evidence to suggest that morah stones were used
as grinding stones. On similar artefacts examined by Richard Fullagar,
fine striations were found to occur at right angles to the incisions on
the surface; they exhibit abrasive smoothing from grinding; and develop
limited polish (polishes appear to develop on hard quartz grains within
the stone matrix) - this is consistent with plant working.
It has also been noted that undertaking use-wear studies on this
type of stone is problematic as the raw material is very soft and residue
films obscure the surface. Nonetheless, taken together, the morphology,
residues and information about use-wear on similar implements are
consistent with plant processing, in this case toxic starchy plants, most
probably dominated by the Yellow Walnut ( B. bancroftii ) and also
Hairy Walnut ( E. insignis ).
Establishing the use of morahs for the processing of toxic starchy plants
has implications for our understanding of the timing and nature of
permanent settlement of rainforest environments. Long term use of
rainforest environments by people may hinge on access to a suite of toxic
starchy plants (see Cosgrove et al. 2007). The development of the
technologies for processing plants such as the Black Walnut(Endiandra
palmerstonii) , Yellow Walnut and Black Pine(Sundacarpus
amarus)may have been transferred from the known methods for
processing cycads, the antiquity of which has been reported as 13,000
years in Western Australia (Smith 1982, 1996). Method of toxic food processing:
Cycas media is a common feature of the vegetation in the dry country on
the margins of the rainforest, and the methods for processing these and
the rainforest species are essentially the same – baking the starchy
kernels for c. 6 hours followed by pounding to a paste, then leaching in
running water for several days. The second step in this process, pounding
to a paste, can also be achieved by grating with a shell (Pedley 1993).
In these studies, three separate lines of evidence are used to determine
function (see Fullagar et al. 1996).
Firstly, a technological study indicating that the
morphology of morahs is typical of grinding stones – they are flat,
with one or both surfaces showing evidence of use. The used surface is
identified by the presence of concave areas where the surface has been
worn down by continuous grinding. Peculiar to morahs are the incised
parallel lines that run perpendicular to the maximum length of the
Use-wear studies, the second stage in the functional
analysis, indicate that these may have been made by quartz flakes as
evidenced, by the sharp angular cuts and cross sectional
characteristics. The raw material, slate, is a very soft stone and as
such the incisions would have been relatively easy to produce. The
incisions in the slate grindstones may serve the same purpose as the
pecked surfaces observed on sandstone grindstones. In the latter case
it is a method used to rejuvenate the grindstone surface to facilitate
the breaking up of grass seed husks. The incised surfaces are always
the used surfaces on the morahs.
The residue study which was the focus of this research has
shown that the incised surfaces provided ideal locations for
preservation/recovery of starch. Most of the artefacts sampled
produced starch grains, though in greatly varying quantities. The
variations may relate to the storage conditions of the morahs which
were different in each case. Nonetheless the starch recovered has
provided a clear indication of target species on the basis of maximum
dimension measurements (see Lance et al. in press). While these stones
appear to have been used for the processing of Yellow Walnuts and
Hairy Walnuts, it is also clear that they were used to process other
toxic nuts, perhaps as they became seasonally available. It is likely
that these residues represent a record of the last use of the stones.
An interesting find is that the one stone, was used to process a different
set of plants to the other grindstones examined here, as indicated by the
small sample of starch granules present on the stone surface. One of the
species that may be present on this grindstone is Macadamia whelani
(macadamia nut). Pedley (1993:139) reports that no information was
found in relation to the processing of M. whelani by Jirrbal-Girramay
informants, nor from Murray Upper, near Tully, and it may not have been
processed uniformly across the region where the morah stones are found.
The identification of this plant as part of the assemblage on this
grindstone may be an indicator of detoxification closer to Babinda.
A second species possibly identified on this stone, the Polynesian
Arrowroot ( Tacca leontopetaloides ) is found on the coast in ‘open
forests and extends into rainforest behind sandy beaches’ (Pedley
1993:117) and as such may act as an indicator of the location from which
the stones are derived (i.e. coast as opposed to tablelands).
Morah stones are used in the processing of toxic starchy nuts. Comparison
with modern reference materials indicates that these plants are likely to
B. bancroftii (Yellow Walnut) and
Hairy Walnut ( E. insignis ).
Other economic species may have contributed to the residue
assemblage as it appears that these artefacts are unlikely to be
single use and are of a size that is easily portable.
We would like to thank Maisie Barlow (Jirrbal), Pat and Alverio Croatto,
Ned Maxwell, Deanna and Ron Stager for access to their private collections
of morah stones. The Atherton Tropical Herbarium staff, especially Rebel
Elick and Bruce Gray, helped us compile the plant/starch reference
collections. Thanks to Don Page, Bernadette McCall and Anna Charlton for
technical assistance. We are also grateful to Ernie Raymont (Ngatjin) for
advice and support. The project was funded by an Australian Research
Council Discovery Project grant, La Trobe University and the University of
Sydney. We appreciated the constructive comments of Alison Crowther and
Catherine Westcott. The authors acknowledge the facilities as well as
scientific and technical assistance from the staff in the Australian
Microscopy and Microanalysis Research Facility (AMMRF) and at the
Australian Key Centre for Microscopy and Microanalysis at the University
of Sydney. Barton, H. 2007. Starch residues on museum artefacts:
implications for determining tool use. Journal of Archaeological Science