I've reported before [1 - 2] on the on-going discoveries in the Tjust area of NE SmÃ¥land province. Here Joakim Goldhahn is employing the country's best rock-art surveyors to work through an area that is turning out to be extraordinarily rich and diverse in Bronze Age petroglyphs. These years will be remembered as a time when the Swedish rock art map was redrawn in a dramatic fashion.
Here are two fresh finds from last week, pics courtesy of my friend Roger Wikell. Some of this rock art is pecked on quartzite, a material so hard that Roger compares it to bullet-proof glass. The cool thing about such images (the motif, apart from cupmarks as below, is usually boats) is that though they hardly scratch the surface of the rock, the pecking has caused microscopic fractures that change the quartzite's colour. And so you can see these images clearly without filling them in even after 3000 years of weathering.
Also cool and unusual is the placement of this particular image panel: it's on the vertical face of an erratic block instead of on the standard softly sloping ice-ground bedrock surface. Roger points out that the shards that can be seen to have flaked from the block may still be under the turf at its foot, and possibly bearing images. Myself, I wonder if the flaking is due to a (ritual) bonfire lit there.
Doctors h.c. Sven Gunnar BrostrÃ¶m and Kenneth Ihrestam paint one of their most recently found cupmark panels with non-intrusive chalk powder + water prior to documentation with permanent marker on plastic film.
While on the subject of Roger Wikell's activities, let me mention that he kindly classified the lithics from my NykÃ¶ping site the other day. It turned out that out of about 25 collected fragments, most were clearly naturally fractured and only three were clearly modified by people. Damn quartz.
I recall Rabbe SjÃ¶berg did some work on dating by rings of lichen on stones -can something similar be used to date petroglyphs?
(OT) "The Consequences of Irrationality" -Howard Camping's claim that the world will end on May 20 is causing misery. Time for the skeptics to change into their superhero costumes!
Yes, lichenometry could give a TAQ date for a petroglyph covered by lichen. But we already have a good typo-chronology for the ships thanks to the fact that similar ships are also found incised on bronze abjects of types found in closely datable graves. Also, in order to see a petroglyph clearly, you have to remove the lichen.
Since the rock carvings by their nature are so sketchy, I hope we may one day find a broze-age vessel preserved under the silt of a freshwater lake somewhere.
Long-baseline sonar mapping (with computers processing the echoes to gain maximum detail) could in theory pick out objects the size of cups, but the military (UK, US have the resources) have been keeping this technology to themselves. Fat chance some institute of marine archaeology can cough up the necessary $$$.
The Hjortspring bog boat from SW Denmark dates from the mid-300s BC, ~150 years after the end of the Bronze Age. It looks just like the boats depicted in late rock carvings. And it was found filled with the weaponry of the warriors who had arrived with it to attack the locals, including the world's oldest chain mail.
If I saw cup-marks like that I'd assume they were natural erosion.
Limestone sometimes erodes in a way that sort of resembles cupmarks. But this is gneiss or granite.