The first generally recognised piece of artwork is abstract in the extreme: a worked piece of hematite with a complex linear pattern etched into it. It comes from Blombos Cave in South Africa, together with similarly engraved bone, shell ornaments and advances in stone tool kits.
Artifacts from Blombos Cave, South Africa (credit: Wikipedia; copyright held by Chris Henshilwood)
Dated at 100 ka, the Blombos culture is regarded by many palaeoanthropologists as the start of the ‘First Human Revolution’. Yet most believe that such a massive cultural shift only properly manifested itself around 40 ka in Europe shortly after its colonisation by anatomically modern humans. It was then that lifelike pictures of animals began to appear on the walls of caves, such as those discovered in Chauvet Cave in France and radiocarbon dated to between 35.5 to 38.8 ka.
Drawing of horses in the Chauvet cave. (credit: Wikipedia)
Such a Eurocentric view is based on the lack of evidence for precedent art of this kind from elsewhere. The adage that 'absence of evidence is not evidence of absence' - attributed to Carl Sagan - recently popped up with sophisticated dating of cave art in the Indonesian island of Sulawesi. The cave-riddled limestones of southern Sulawesi have long been known for artwork on the roofs of caves and in some of their darker recesses, including sketches of local animals, humans and a great many stencils made by blowing a spray of pigment over a hand placed on a rock face. The pictures were thought to be relatively recent.
Painting of a dwarf water buffalo and stencils of human hands from a cave in SW Sulawesi (credit: Maxim Aubert, Griffith University, Australia)
A joint Australian-Indonesian group of Archaeologists used a specialist technique to date them (Aubert, M. and 9 others 2014. Pleistocene cave art from Sulawesi, Indonesia. Nature
, v. 514
, p. 223-227. See also Roebroeks, W. 2014. Art on the move. Nature (News & Views)
, v. 514
, p. 170-171). Like many paintings in limestone caves, with time they become coated with calcite film deposited from water flowing over the rock surface, known as flowstone or speleothem. It is possible to date the film layers using the uranium-series method to derive a maximum age for the encased pigment from speleothem beneath it and a minimum age from the layer immediately overlaying it. One of the hand stencils proved to be the oldest found anywhere, with a minimum age of 39.9 ka, while sketches of animals ranged from 35.4 to 35.7 ka. To see more images and view an interactive video about the Sulawesi finds click here
The discovery by Maxime Auberts and his colleagues has set the cat among the pigeons as regards the origin of visual art. The paintings’ roughly coincident age with the earliest in Europe raises three possibilities: the artistic muse struck simultaneously with people widely separated since their ancestors’ emergence from Africa; somehow the skills were quickly carried a third of the way around the world from one place to the other; the original migrants from Africa took artistic ability of this kind with them to Eurasia, perhaps as early as 125 ka ago
Three points need to be considered: whether in Europe or eastern Indonesia, cave art is preserved either on the roofs or in the deep recesses of caves, where it is more likely to survive then in more exposed sites; preservation by speleothem enhances longevity and the oldest works are in limestone caves; many more archaeologists have researched caves in Europe than in the far larger areas of Asia and Africa. A view worth considering is that art may have begun outdoors, in a well-lit site on whatever ‘canvas’ presented itself. The artists’ choice of cave walls in Europe and Indonesia may have resulted from the need for shelter from rain and/or cold, whereas much of Africa and Australia poses little need for ‘interior design’. Besides, what if art began on the most easily available canvas of all – human skin! My guess is that the record will widen in space and deepen in time.
Petroglyphs in desert varnish near Las Vegas, Nevada, USA. Image via Wikipedia
Early occupants of semi-arid areas found a cultural use for what is one of geology’s greatest annoyances: desert varnish. Annoying because once developed it leaves an extremely durable brownish to black, shiny coating over rock surfaces: be they dunite, marble or quartzite, sandstone or granite, desert outcrops all look very much the same. You have to bash them unmercifully to see the true texture and mineralogy, and, except on images of thermally emitted infrared, remote sensing doesn’t help as the varnish has the same reflectance whatever the wavelength of radiation. Yet to the former inhabitants of dry lands – and latter day ‘taggers’ – desert varnish has been irresistible for millennia. Lightly peck away with a sharp pebble – and some ability to depict your thoughts – and you can leave an almost indelible sign that you and your ideas were at that very rock face: a petroglyph, picked out for all time in the manner of chalk on a blackboard. Even more spectacular, given an oversight of a varnished cobbly plain and it is possible to magnify your tag, or whatever petroglyphs once signified, a hundredfold or more. That happened on the famous Nazca Plain of Peru and continues to do so in especially dry places in the south-western US, as around Lake Havasu City in Arizona. Varnish forms only on the exposed face of cobbles, the downward side remaining more or less the original rock’s colour; generally lighter. Turn over the cobbles in an organised way, with a degree of persistence as well as talent and you too can make your mark on Google Earth! (Do not pass this on to Banksy – it doesn’t hurt the ecosystem, but will annoy the authorities immensely).
Ancient art depicting a hummingbird on the Nazca Plain, Peru. Image via Wikipedia
For all this period of artistic endeavour, stretching back in some places to the Palaeolithic, it now seems that desert varnish also records how environments have changed as well as the religiosity, humour or downright egotism of its inhabitants (Dickerson, R. 2011. Desert varnish – nature’s smallest sedimentary formation. Geology Today, v. 27 (November-December issue), p. 216-219). As well as reviewing how the varnish forms (see also Desert varnish in EPN May 2008, in Subjects: GIS and Remote Sensing)., Dickerson flags-up the little-known fact that the minute layers produced as varnish imperceptibly develops record changes in environmental conditions – wet, dry and middling – and, moreover they can be dated precisely despite being extremely thin (e.g. Liu, T. & Broeker, W.S. 2008. Rock varnish microlamination dating of late Quaternary geomorphic features in the dry lands of wester USA. Geomorphology, v. 93, p. 501-523). Liu and Broeker were able to match variations in the colour of varnish layers with important climatic episodes of the Northern Hemisphere, such as the Younger Dryas and other warming-cooling, dry-wet shifts as far back as the Last Glacial Maximum. Their approach offers a chance of dating petroglyphs and thereby cultural changes during critical stages in the history of modern human migrations, occupations and abandonments, even when no artefacts or bones remain. That is because once made, petroglyphs gradually become varnished themselves.
- Oldest North African rock art (dienekes.blogspot.com)
- Sloan Canyon (hikercarl.wordpress.com) Highly recommended for petroglyph images