It looked to be a routine excavation of what was thought to be a burial mound. But beneath the mound, archaeologists from the Norwegian University of Science and Technology's Museum of Natural History and Archaeology found something more: unusual Bronze Age petroglyphs.
     At first, the museum researchers dedicated just three weeks to the excavation in Stjørdal. Then came the surprises. First, it turned out that mound builders had used an existing hill as a starting point - which of course saved them time and effort. The hill itself made the burial mound even larger and more monumental than it might have otherwise been.
     But researchers suspected there might be another reason for the choice of the hilltop when they uncovered the remains of two cremations, or rather a fire layer that also contained bits of bone. Underneath they found many petroglyphs, including eight drawings showing the soles of feet, with cross hatching. There were also five shallow depressions, says museum researcher and project manager Anne Haug. Two boat drawings and several other drawings of feet soles with toes were also found just south of the burial mound.
     "The tomb might have been deliberately constructed over the petroglyphs, probably as part of funeral ritual. Based on the type of characters and especially the drawings of the foot soles, we have dated the artwork to the Bronze Age, about 1800-500 BCE," says Haug. "Why there are foot sole drawings beneath the tomb is a puzzle. But if we interpret the find in terms of a fertility cult, it may be that the soles represent God and life-giving power," she adds.
     There was a similar discovery in an area called Jong in Bærum, where petroglyphs depicting foot soles were found under a tomb that dates back to the Bronze Age. In a Nordic context, this phenomenon is common, and there are several examples where burials were combined with rock art, particularly petroglyphs of foot soles from Bohuslän, a World Heritage site in Sweden.
     It's not yet clear if the grave was put in place the same time as the petroglyphs, Haug says, but the analysis is still ongoing. The scientists have found about 900 grams of burned bone; they hope to be able to carry out C-14 dating of the material so to find the gender and the age of the individuals in the grave. "Currently, we have found several human teeth, as well as what may be remains of human ribs. We also found an animal tooth that suggests that one or more animals may have been laid in the tomb along with whoever is buried there," Haug says. A flat corroded metal object was among the very few objects found in the burnt layer of the tomb, and the object will be X-rayed for analysis.
     A burial ground in the area was first described in 1818 by Lorentz D. Klüwer, and archaeologist Karl Rygh also described the site in 1879. It is likely that the graves that have been excavated in the most recent dig are the last remains of this burial ground. The rock art found at the site is a type called South Scandinadivan agriculture carving and is dated to the Bronze Age, and the tomb probably dates to the transition between the Bronze Age and Iron Age, from 500 BCE up to the year 0.

Edited from Norwegian University of Science and Technology (31 January 2011)