**Caution this page may contain images of persons now deceased**
Geology of Rainforest Aboriginal Stone Tools
source pers comm rainforest people Ngadjonji, Yidinji and Mamu
Peter E Siegel, Lithic Technology Vol 14 No2 (August 1985, pp90-94) Edge
Angle As A Functional Indicator: A Test
Patrick Kooyan, Understanding Stone Tools and Archaeology Sites,
University of Mexico Press 2000 pp90-94
J. Jeffrey Flenniken and J. Peter White 1985, Australian Flaked Stones,
Records of Australian Museum 36 pp131-151
R. V. S. Wright, STONE IMPLEMENTS Department of Anthropology,University of
http://www.awrana.com/index.php?value=wear-residues , Summary of
Peter Hiscock, hiscockinpress.pdf, Looking the Other Way
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. Rocks include schist, basalt and quartzite but most are
hornfels. The working face may be convex, concave or flat.
What were Ooyurkas used for?
80-90% of Ooyurkas that have been discovered have been dug up by
ploughs while planting Sugar Cane. None have been radioactive carbon
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 such as rainforest aboriginal 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
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. 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 or the natural pits in vesicular basalt., just
the size of the nuts and a hefty hammer stone.
Geology and surface features
Ooyurkas are made from
coarse Crystalline Basalt (only two known of this material)
Quartzite(only two known both from RussellRiver area)
Hornfels (the most common rock used)
(The choice of these rock types is significant and is covered in
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.A
all ooyurka held by the webmaster clearly fit best in the
right hand only
Conclusions on uses of Ooyurka
Wet season use. Most likely nothing to do with food at all. Men and
women used the same tool for different purposes. (April 2017 webmaster pers comm.with traditional owner) Female use Ooyurka
to strip thorns off lawyer cane stems,
thread making bark blankets for example from the inner
bark of theRed Tulip Oak(Argyrodendron sp.) and
rope making from lawyer cane
very fine grinding of for example medicinal materials
Male use Ooyurka:
fine smoothing, shaping and polishing of the surfaces of
wooden shields, spears and boomerangs
(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.
Grindstones are common in the tropical rainforests of far North Queensland
and have often been found by farmers ploughing paddocks.
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.
Residue analysis has become a frequently applied method for identifying
prehistoric stone tool use. Residues adhering to the stone tool with
varying frequencies are interpreted as being the result of an intentional
contact with the worked material during use. Yet, other processes during
the life cycle of a stone tool or after deposition may leave residues and
these residues may potentially lead to misinterpretations. Production,
retouch, prehension, hafting, various incidental contacts during use and
deposition may lead to residue depositions that significantly affect the
accurateness of identifications of tool-use. Closer attention is required
regarding the interaction with independent wear studies and a step-wise
procedure in which a low magnification of wear traces is used as a first
step for selecting potentially used flakes in archaeological contexts. In
addition, residue concentrations on a tool’s edge should be sufficiently
dense before linking them with use.
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 such as the quandong.
another use is as a "plate" that is as a flat surface out of the
dirt to put plant and animal foods on either pre-processing
and post-processing hence this the presence of such a
variety of plant and animal residues.
no doubt they were used for grinding softer materials like fine
grinding ochres or medicinal materials but the slate just isn't
robust or thick enough for heavy duty work and no need to use a
softer imported rock when so many local robust flat surfaces are
available (basalt, granite, quaertzite, hornfels, dolerite to name
just a few)
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
simply roll the ripe quandong across the surface with the palm of your
hand and the skin and flesh comes off onto the surface and into the
grooves. This low pressure would leave little residue. Rainforest
nuts are pretty hard, if morah stones were used for crushing nuts you
would expect some impact points in the soft rock where the user misses
the nut from time to time. Morah stones are thin
(65mm) - for crushing nuts a thicker, more robust base seems both
warranted and obtainable. The flat morah could also be used as a "plate" to keep crushed
nuts out of the dirt - hence the starchy residue in some studies
and the indications of the presence of meat. It will be
interesting to see if future studies indicate the presence of
haemoglobin. Why would you place meat / fish / eel in the dirt if a
morah is handy? 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. It is likely the morah would be used for other tasks such as final
grinding or holding of ochres.)
Morah stones occur in a region where the processing of toxic starchy
plants is common, 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. These were said
to be used to crush zamia and walnuts.
The upper stones are known as ‘mugaa’.. (webmaster note: mugaa
is the term in the Ngadjon language "moogi" is used in other languages) Mugaa 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
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
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.
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. 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
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. 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). 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.
Residues are examined visually by microscopic analysis of extracted
residues, several samples were selected for staining so that any highly
degraded, fragmented or amorphous residues could be identified.
Chemical analysis of resudues used as follows...
Methylene Blue (C16H18N3SCI) was used to highlight non-lignified
cell walls such as cellulose fibres within plant material. The stain,
which is a water soluble dye, binds to the acidic pectins on the
cellulose cell wall that become stained with various shades of
Orange G (C16H10N2Na2O7S2)–an acidophilic dye, was used to identify
animal fibres such as collagen and keratin by binding with proteins in
the target material, typically staining them orange
THemastix® testing strips indicate the presence of haemoglobin (and
other iron containing materials). Tools that were presumed to be in
contact with animal material (as implied by the presence of collagen
fibres or the visual appearance of other tool-use residues) If colour
change had not occurred after one minute, the sample was deemed
negative for haemoglobin.
how an ancient waisted axe is re-united with its lawyer cane handle,
by a Yidinji elder (now deceased - used with permission), using
traditional materials and methods... A waisted axe has one doubly ground edge and a pecked or ground groove
to facilitate a handle.
The waisted axe was a universal stone tool. Fitted with a lawyer can
handle, it is the main tool / weapon carried by men as they traveled from
place to place.
If traveling to new territory, the remaining stone tools were carried by
the wives in baskets.
If traveling to an annual camp, often a set of tools would be left, easily
found, amongst the large buttress roots of a rainforest giant.
The waisted axe has a medium angle ground edge so it can be re-sharpened
periodically. So while the initial making of the axe was time intensive,
unlike a pecked axe it could be re-furbished with a new edge.The medium
edge could be used for...
light cutting and felling
breaking open nuts / fruit breaking
to quickly chip off a razor sharp flake of quartz or quartzite
to open old logs for grubs and game
opening holes in trees to collect honey
dispatching snakes amongst epiphytes in the canopy
dispatching edible wildlife
as a weapon for informal protection (but not for formal combat)
some waisted axes, show virtually no wear, were highly polished and
made of exotic stone from distant trading - these may have been
prestige items, for show (equivalent to a bloke today having an exotic
The majority of stone tools were ground edge axes in varying sizes with
medium to blunt double ground edges.
As with all stone tools, they would be used for a multitude of purposes.
Women would be the main users and the preparation of food the main area of
use.This use would involve, breaking, stripping, crushing. Digging was
done with a hardwood stick sharpened at one end and around 1.25 m in
You can tell how an axe was held by manipulating in the hand. There is
only one position where holding it feels entirely comfortable.
Smaller ground axes were used in the right hand (I know of no examples of
left-handed stone tools). The heavier the work the bigger and blunter the
Pecked axes had the sharpest edge and hence the shortest useful lifetime.
They could only be re-sharpened by making the new tool considerably
smaller and it probably wasn't worth the effort. Often a hastily broken of
piece of quarts or quarzite could be chipped off.
Their main uses were:
stripping thorns off vines
splitting lawyer cane
to skin an animal
pecked tools to scrape skins have a distinctly curved edge
to gut a fish
to finely sharpen an object
note:ritual cutting would entail the use of a razor sharp flake of
The large broadaxe may have a single or double, equal or unequal very
blunt ground edges. It is used with two hands for very heavy work.The
blunt edge facilitates brutal work. The tool is difficult to damage.
A flattish piece of basalt lava with appropriately placed natural gas
vesicle pits could be enhanced by further grinding out the pits to make a
much prized nut cracking stone.
The rainforest provided a ready supply of nuts which were eaten by all in
the "Wet Season" and by the women for a good portion of the year.
As mention previously... There were four kinds of nuts generally harvested
(listed least toxic to most toxic)
The nuts are large and have a tenacious outer cover and a hard inner nut.
The nuts are placed in the pits and struck with a hammer stone.
Vast quantities of nuts would have been harvested and stored in damp pits
(climate controlled conditions to prevent cracking)and where they could be
kept intact for several months. In order to get the Black Walnut before
the animals did (being the least toxic this nut was a favourite of animals
and humans) , the rainforest people would climb into the canopy using
lawyer cane straps in order to harvest these nuts.
The hammer stone is used primarily for cracking nuts in the pitted nut
rock shown above. The hammerstone, in larger sizes, would also be
used as a hammer for driving in objects, to assist in splitting The
cylindrical grinding stone could be used for a variety of grinding
purposes. On the morah stone it could have been used to finely grind
ochres for ceremonial purposes. On a harder platen it could have been used
to grind seeds or refine the grinding of crushed nuts in the preparation
of a nut based "bread".
The "Missing" Rock - Obsidian - volcanic glass?
Small patches of poor quality obsidian rock (volcanic glass) are found on
the Atherton Tableland, McBride basalt province and near Chillagoe, all
easily otainable by trade. Good quality obsidian should be obtainable
along ancient trade routes
(determined by terrain analysis) extending as far as Mount Isa.
Obsidian glass can be easily chipped into razor sharp surfaces -- so why
are obsidian tools missing from the suite of tool rock types ?
One needs to avoid the Western misconception of "one tool / one
use". The same tool could be used to several tasks
for example a medium size ground edge axe could be used as a hammer, a
scraper, a plane, a knife, an axe, a crusher
a pointed tools might function as a scraper, cutter, gouger, plant
shredder ... it all depends on what is at hand at the time
the same tool may have a particular ranges of uses by men and a
different range of uses by women
some items or objects may be gender specific or taboo for
particular individuals / at particular times
The best guide on tools use is "comfort of holding". If in a certain
orientation the tools fits well in the hand then that is likely the
position its was held in during use.The writer has never come across a
Following on from "2" it is likely that in the process of hunting
and gathering, an individual would come across a a piece of the right
kind of rock that fit well in the hand and fashion a tool from it. The
collection of suitable rocks was probably more "opportunistic" than
"deliberate". The exception to the rule would be "prestige" axes as
described below in "4"
Each campsite would have the complete set of tools to match the
particular food sources exploited. The existence of some exceptionally
finely worked virtually unused axes using rock from distant locations
These exceptional axes would be carried from site to site - most show
little or no wear and their purpose may have been to impress others
met on route.
The People of the Rainforest appear to have few complex "flaked"
tools at best they could be described as "pecked" tools, that is some
basic edge flaking.The main reason being a lack of suitable rock.
The paucity of complex "flaked tools" is more than compensated by
the sophisticated range of ground edge tools
Factors from western culture that need to be taken into account in
order to select the right stone for a tool...
sharpness of fragments
strength in2 -3 planes
ability to "flake"
ability to hold a ground edge
amenity to be re-tooled / re-sharpened/ repaired
will "glue" for lawyer can handle adhere
Through experience and learning the Rainforest People just know which rock
is the best for a given task.
Why Metamorphic Rocks?
Metamorphic rocks predominate in larger stone tools.
Metamorphic rocks are derived from pre-existing rocks that are cooked and
squeezed in the solid state. These conditions, which take place without
melting, cause the rock to recrystalise forming larger denser
interlocking crystals. The resultant rock may have more uniform hardness
and be stronger in either two or three directions depending on the
rock. As a result theses rocks can be more reliably shaped and
flaked that either some sedimentary rocks (too soft) or some crystalline
igneous rocks (too friable). In the tropics, a region of intense
weathering rock some metamorphic rocks being less permeable to water due
to their higher density and interlocking crystal structure suffer less
Phyllite and slate, are associated with grinding technology and occur
mainly in the form of ground and incised tools such as axe bevels and
incised grinding stones.
It has been suggested that their presence in the rainforest indicates
interaction and some form of trade.
Hornfels is a contact metamorphic rock formed when mudstone /
shale, or other clay-rich rock, and are intruded by a hot igneous body
(usually granite), and represents a heat-altered equivalent of the
original rock dominantly composed of silicate + oxide minerals in varying
proportions. Because pressure is not a factor in the formation of
hornfels, it lacks the foliation seen in many metamorphic rocks formed
under high pressure and temperature regimes. Pre-existing bedding and
structure of the parent rock is generally destroyed during the formation
it is useful as raw material for stone tools as it exhibits no
directional planes of weakness.
it's horny appearance and conchoidal to subconchoidal fracture
mean it will take and hold an "edge" by hammering or grinding
as a stone tool it has a uniform hardness which means it will have
it is water resistant so it is not weakened by immersion nor
subject to exploding in a fire
It is often difficult to identify hornfels without microscopic
observation, or knowledge of its association with a magma body, as it is
typically non-descript in hand specimen. Under a microscope the structure
of hornfels is very distinctive, with small, generally equigranular,
mineral grains fitting closely together like the fragments of a mosaic or
a rough pavement.
Quartzite a metamorphic rock formed when quartz-rich sandstone or
chert has been exposed to high temperatures and pressures. Such conditions
fuse the quartz grains together forming a dense, hard, equigranular rock
of incredible strength.
makes hard durable stone tools though time consuming to
work with due to it's hardness
make good "impact" tools for shaping / creating "chipped edges"
it is useful as it displays no directional planes of weakness
can be polished to a high degree so useful for making tools used
for smoothing and polishing things like spear shafts and shields
in an unpolished form useful for crushing and grinding tools and
bases as its is less likely to impart stone grains / chips /
fragments to the food as compared to for example: sandstone
some quartzite has a conchoidal fracture so an "edge" may be made
by less labour intensive hammering but edges are not as good as
those of other rocks like hornfels and crystalline quartz
outcrops are very likely used a site for grinding and shaping
tools made of softer rocks like hornfels and greywacke - no clear
permanent grinding site has been identified though logic suggests
thier existence. The challenge is that many quartzite outcrops are
in deep canyons, in extreme terrain within dense rainforest and have
probably not been recognised for what they are.
impact between two quartzite cobbles will produce sparks but
evidence of it's use in fire-making is lacking and sparks are a poor
alternative to the wooden bow and block method
Greywacke is a variety of indurated sandstone generally
characterised by its hardness, dark color, and poorly sorted angular
grains of quartz, feldspar, and small rock fragments or lithic fragments
set in a compact, 15% clay-fine matrix. The hardening is caused by heat or
baking near the end of the rock cycle processes of erosion, transport of
eroded material by rivers, deposition onto the sea floor and then pushing
up by plate tectonic movement. It remains a sedimentary rock as the heat
and baking are not sufficient for the minerals to recrystallise and become
a metamorphic rock, nevertheless it is hard enough to be used for ground
retains bedding planes and it's relative softness mean it will
form abundant flat shapes suitable for ground edge axes that require
a thick "wedge edge"
softness means it can easily be "re-edged" and won't be destroyed
by heavy use so it is useful for heavy duty tasks such as tree
water, scratch, stain resistant, gritty surface so it can be used
as a flat surface for shaping wood / bone or cutting, grinding
and crushing food materials or for rolling fibres out to make rope
for nets and line for fishing
Slate is created by the alteration of shale or mudstone by
low-grade regional metamorphism. It has a medium hardness. Bedding is well
developed and slate breaks into very flat smooth sheets.Easily incised by
- for example a flake of crystalline quartz
most commonly used as a morah stone (often found fragmented -
destroyed after ceremonial use? or just not very robust?)
most often incised with sub-parallel grooves to facilitate
the fine grinding of relatively soft materials for example:
ochres and medicinal materials. As a "base" using a top
"mugaa" stone made of lightly abrasive granite. Some morah
stones show rounded central wear
possibly used to roll and remove , through the use of the
palm, the thin edible surface off abundant fruits like
use as a "plate" - the flat surface and large surface area is
useful for keeping food items off the ground for example: cut meat
or crushed nuts thus "residue studies" may misinterpret actual it's
use use as a plate. The slate is simple too soft and too thin
(maximum thickness 65mm) to survive the forces involved in cutting
meat or slicing / crushing large hard rainforest nuts
may be marked with symbols of unknown meaning - perhaps
spiritual / "men or womens business", maybe a map or message
Tools may also made from fine grainedigneous rocks such as
dolerite, rhyolite and basalt (sometimes metamorphosed basalt)
Crystalline quartz , due to chonchoidal fracture resulting in very sharp
edges are available throughout the rainforest area. "Milky" "bull"
quartz though not as sharp as crystalline quartz is
ubiquitious and can be fractured to form useful sharp fragments.
"bull" quartz (opaque) - core from which flakes have been removed
Chert is a micro-crystalline sedimentary rock found at some
distance inthe Chillagoe area that creates when fractured or flaked
very sharp chonchoidal edges, while chert is present , probably due to
trade, rainforest crystalline quartz appears more commonly used as
it is local. Evidence of local trading. On the Atherton Tablelands there
is likely a small local patch of poor quallity obsidian evidenced from a
few sharp fragments scattered in the rainforest that may or may not be
tools. Crystalline Quartz and "Bull" Quartz - the majority of
small "artefacts" (small sharp fragments and flakes) are made of
quartz. It is extremely difficult to establish whether edge modifications
represent deliberate retouch or use-wear damage, especially on the edges
of inferred ‘scraping implements’. The raw materials are easy to find and
sharp edges are easy to make, so much so that it is probably easier to
create a new "artefact" that to retouch an old one. Quartz artefacts are
found scattered everywhere in the rainforest as if when hunting /
gathering they are taken along as a sort of "pocket knife" and readily
discarded when carrying them is no longer convenient.
"crystalline" quartz(semi-transparent - makes sharper flakes
easily found and easily chipped to a sharp edge ... quartz
fragments are scattered throughout the rainforest and act as "pocket
knives" . It is difficult to say which fragments are natural and
which deliberate unless there is evidence of a clear hammer impact
Dolerite is a mafic, holocrystalline, subvolcanic rock equivalent
to volcanic basalt or plutonic gabbro. Also known as diabase it forms
dikes and sills from typically shallow intrusive bodies and often exhibits
fine grained to aphanitic chilled margins. So it is dark coloured and very
fine grained. It is a very hard rock, difficult to drill, shape or quarry.
the very fine grains make this rock strong in all planes
not amenable to "chipping" only useful as a ground edge tool
it can be ground to a smooth fine edge and an example traded from
the Kalkadoon people in the Mount Isa region 1200km away
appears to be a "prestige item". While dolerite is found locally
within the rainforest it does not appear to have been chosen for
tools - preference seems to be for imported material reasons unknown.(see Axe #4)
tools made from this material would be very time consuming to
produce as starting from angular equidimensional source material the
axe would have to be entirely ground to it's final flatish shape
the relatively sharp edge means the tool would be used to chop or
cut softer materials (this may initially appear counter intuitive
but thick durable "wedge edges" are better able to with stand
the immense forces of chopping harder materials and keener / sharper
edges are only up to the task of chopping softer materials)
when wet it loses about 1/3rd of its strength
Basalt is black volcanic lava. It is found in three states in the
Massive basalt from flows.
Vesicular basalt - porous with natural "vesicles" and pits(from gas
Columnar basalt formed by hexagonal shrinkage cracking in slow cooling ash
buried lava flows
some ookurya are made from what appears to be a unique source
of a particular coarse crystalline basalt, the quarry location
unknown, however, massive basalt in general is not
particularly useful in tool making other than for crushing things
like nuts and making lawyer vine into fibre. The flow-bands create
difficult to see zones of weakness so the rock is tricky to shape or
sharpen but it will retain heat so is handy for pit ovens.
vesicular basalt creates tools in it's natural form as rounded
cobbles or boulders. The material is ubiquitous in the local region.
Large pits are ideal to; hold large rainforest nuts while they are
cracked and open - the pits are ubiquitous in the local
volcanic region. Elsewhere sandstone is used and uniform pits are
ground out using a larger version of a fire bow , water and sand.
Fine vesicles as found in locally available scoria could make ideal
sandpaper or wood shaping tools but there is no clear evidence of
columnar basalt forms hexgonal shaped columns up to about a half
metre across that split horizontally to form flat hexagonal surfaces
that may be useful near the source but are too bulky to carry any
distance. There is no clear evidence of their use.
Gneiss is a layered metamorphic rock. The light layers are bands
It is fairly easy to cleave a block into flattened layers. Stone tools
made of gneiss appear rudimentary and show significant wear
gneiss Imports: Rhyolite and fine-grained raw materials
Rhyolite, chert, and other fine-grained raw materials were possibly
transported to the site from drier areas with different geology located to
the west of the rainforest region, where these raw materials are available
. No known local outcrops or exposures of rhyolite are found. The closest
known source is in the drier sclerophyll area located to the west of the
Evelyn Tableland. Few rhyolite tools are found. In the tools found the
stone material appears to be retained and reused but perhaps because of
it's hardness, hence difficulty to work, rhyolite may just have been
and unpopular material. Both options may be a result of the distance
rhyolite had to be transported. It is possible that quartz was not only
locally available but also the raw material favoured for use in stone
working by Aboriginal rainforest people.