Plant Impressions (Morocco)

[painshill]

I acquired this item from an artefact dealer who believed it to be a Neolithic “shaft abrader”. These artefacts are usually from coarse/abrasive stones (this is silicified sandstone, bordering on quartzite) and were used to smooth arrow shafts and wooden spindles for other uses. There are also similar artefacts used for making tubular stone beads.

Unfortunately, I don’t have a precise locality apart from Moroccan Sahara but in any case it was found in an artefact-rich area and may well have been manuported to where it was found. It fits neatly in the hand for such a purpose but I didn’t believe it to be an abrader, although I purchased it anyway.

Although such artefacts often have multiple hemispherical grooves, the arrangement of a pair of grooves so close together wouldn’t be usual (or practical) and I was even more suspicious that there are two identical pairings on the rock. Closer examination of the interior of the grooves also doesn’t show the typical parallel scratching that arises from such abrasion.

It has to be a plant impression, but does anyone know what plant, or even what portion of the plant might have this kind of double-barrelled structure? It’s sufficiently distinctive that I hope someone recognises it. There are also a couple of surface patches that might be from leaf or larger stem impression (to the left and above the grooves on the right of the first picture). They have shallow striations.

Sorry about the poor focus on that last picture but it should give you some idea that the grooves are symmetrically hemispherical. The combined width of each pair of grooves is about 10mm.

Edited November 5, 2014 by painshill

[tmaier]

Wow, it has what appears to be grooves in it like a calamites stem.

And the other resemblance to a calamites is that they are commonly found collapsed, creating that double groove.

Calamites with ridges and double groove...

(not saying it IS calamites, but maybe a similar plant)

[painshill]

Might these even be ridges from a fragmented larger stem of something (such as Calamites) which are just coincidentally grouped in pairs?

The additional groove accompanying the top pair is just another singleton laying across the pair. It's not connected as a side stem or offshoot.

Edited November 5, 2014 by painshill

[tmaier]

In nature walks, I've seen reeds and other hollow stem plants pucker in like that.

Off hand, I don't know of any plants that have paired stems like that.

The "V" shape is very much like a pucker of a hollow stem.