Skip to 0 minutes and 11 secondsWe can look at assemblages of stone artifacts. We can find out how they're made-- the stone materials they've come from-- sometimes track the source of the stone-- how far it's actually come. And we can look at the methods of manufacture. The life of an artifact-- even one that hasn't been used-- they'll accumulate various kinds of wear on the surface. And residues can be transferred. That is, small bits of organic and inorganic material can get transferred onto the stone. Of course, some of them are actually used. And they're particularly exciting, because they give you access to the kinds of resources that people were using in the past.
Skip to 0 minutes and 51 secondsAnd so, if we can actually identify some plant material or wear that indicates plant processing and then find out what species it is, then we can get a handle on what particular resources were being used and what was available at the time. I use the term "tool" to refer to something that's actually been used. And by that I mean it's got evidence of use. And the evidence that I'd be looking for would be either wear or residues or some other indication of use. But the particular stuff that I've been interested in is microscopic wear. So, if we look at the artifact under a microscope, then you'll get different kinds of wear.
Skip to 1 minute and 30 secondsAnd the main forms that we look at are fractures or scarring of the edge-- edge rounding-- there's scratch marks or striations which show you the orientation of use. If they're going in a certain way, then-- indicates that's the mode of use-- the motion of use. Sometimes edges get worn in a very specific way. They get smoothed and reshaped, to form a kind of bevel. Sometimes you develop a polish from use. And the polishes can often indicate classes of materials. So, if you are scraping a piece of wood or skin or shell or bone or antler or other materials, if you have the same edge angles and the same kind of action, all of it will develop the very distinctive polish.
Skip to 2 minutes and 17 secondsBut fortunately, now, in the last 30 years or so, people have been looking at these tiny traces of organic and inorganic material-- what we call "residues"-- usually microresidues. And so the techniques for looking at microorganic material and identifying them taxonomically has improved just enormously. And that's where the other work of the archaeochemists come in. Here at Liang Bua, there's a fairly continuous record of stone tools, from the late Pleistocene all the way through to the Holocene. Yeah. [SPEAKING INDONESIAN]
Skip to 2 minutes and 57 secondsYeah. All of these, again, are Holocene in age and made by modern humans-- our species. They differ from the stone tools that are found in the lower layer, from the Pleistocene, that were made by Homo floresiensis. One of the areas where there appears to be a difference between modern humans and Homo floresiensis, in the tools, is the selection of particular raw materials. In the Pleistocene layers, the preferred material-- the majority of the stone tools are made from silicified tuff, which is very common in the area. Whereas in the Holocene layers and modern humans, we see a preference for chert, as well as other materials that are probably more rare on the landscape.
Skip to 3 minutes and 42 secondsAnd so that's the only distinction, so far, that we can see-- a possible difference, in terms of at least the use of materials on the landscape. In terms of knowing the age of the stone tools, well, that's based on the stratigraphic context and the evidence that we receive from other experts, such as Burt Roberts and others, who have dated the sediments. Sometimes we use charcoal dating or carbon dating. Another case, we're using luminescence and other OSL techniques and also trying to date the tephras using other isotopic methods. [SPEAKING INDONESIAN] This is a big-- a really big flake that has been retouched. Several flakes have been taken off this piece.
Skip to 4 minutes and 31 secondsAnd then they've sharpened the edge and been using it more than once. It's made from silicified tuff. This material is very good for making stone tools. It's easy to work, but yet it's very, very hard. And so it really makes great stone tools. This is a radial core that shows several classic signs that we find on stone tools, such as the bulb of percussion, the striking platform, as well as the fine, sharp edges on the flake. Jatmiko's just described that this side is the ventral surface of the tool, and this is the dorsal surface. And on the dorsal surface, we can see many additional flakes that have been taken off.
Skip to 5 minutes and 6 secondsThis is a very fairly common finding here at Liang Bua. And we not only find the cores, but we find the flakes that were taken off. So what Jatmiko is showing here is that on one side is a flake from the stone-tool-making process. In this case, it's silicified tuff-- of a greenish color. But on the other side we have a jaw of a giant rat, cemented to it. It's very common in the layers, here at Liang Bua, that we find many stone tools as well as many faunal remains. In some cases, being in the ground together for a long time, they've become cemented together like this, again.
Skip to 5 minutes and 42 secondsBut it shows us the association between modern human behavior with the surrounding animals. In this case, it's likely a species of Papagomys, which are the giant rats that still live here on Flores today. Homo floresiensis, sadly, has gone extinct. And it would be interesting to try and find out why. Maybe it had something to do with the kinds of resources they had access to, perhaps what was available to them, and, alternatively, what made modern humans-- Homo sapiens-- especially good at inhabiting that environment. Liang Bua is one of many really fantastic archeological sites throughout Indonesia. But it's special and known to the world because of the discovery of Homo floresiensis.
Skip to 6 minutes and 29 secondsAnd, in that respect, the research that is ongoing here at Liang Bua is very important for understanding the past. And, as humans, we're very curious about our past. And we have many questions surrounding human evolution in general, and also many questions about Homo floresiensis. What is its relationship to us? How did it get here? What other fossil species is it closely related to? The discovery, especially initially, was very controversial. And so the ongoing work here is an attempt to try and resolve and answer some of those questions that weren't answerable at the time of the discovery and build up the evidence so we better understand this.
Skip to 7 minutes and 8 secondsBecause Liang Bua is clearly a site where two different species of hominins have been in the past 100,000 years.
Stone artefacts (also known as “lithics”) are tools that are partially or completely made from stone and show evidence of human use.
Stone tools accumulate various kinds of use-wear and residues that provide information about their design and function. This evidence sheds light on the resources exploited by humans in the past, and can provide information on the evolving interactions of humans and their surroundings over time.
A great deal can be determined from examining stone tools with the naked eye (e.g. the method of tool manufacture and use-wear). Nevertheless, the work of archaeochemists plays a significant role in extracting additional evidence from stone tools (e.g. microscopic residues and ancient biomolecules).
Stone Tools at Liang Bua
The stone artefacts used by Homo floresiensis at Liang Bua and excavated from the Late Pleistocene layers are technologically similar to those used by modern humans (from the Holocene epoch) in terms of the knapping techniques used to make them. Nevertheless, the Homo floresiensis and modern human assemblages vary in terms of raw materials. For example, the most prominent raw material used by Homo floresiensis is silicified tuff, whereas the stone tools used by modern humans were made primarily from chert.
What information can be extracted from stone tools and what role does archaeochemistry play?
How might stone tools shed light on why Homo floresiensis went extinct?
© University of Wollongong; National Research Centre for Archaeology (ARKENAS); Lakehead University