Initiation, African fractals and Sand Divination.
Here briefly, is the Bamana Sand Divination process. Now whilst Geomancy may be familiar, the actual significance is made lucid in this TED talk, By Ron Eglash.
4) The two newly generated symbols, now placed below the original four, are again
paired off to generate a seventh symbol.
5) After this, the original four are read sideways to create four more symbols, and the entire process is repeated, producing another group of seven. In the final step, the first and last from each group of seven are paired off to generate the final two symbols.
Eglash In his TED Talk, describes how he was initiated into a Priesthood,

Eglash further explains the complex underpinnings of the Bamana Oracle system, which is based on mathematical recursion. Like a tree, a simple symbol (representing an Archetype)) is recycled many times, issuing 16 expressions, all representing the complexity captured in the the moment. The Art of The diviner is then to interpret the 16 newly generated Archetypes.
Agrippa has written of a very similar Geomantic system, where each of the symbols is given a house, much the same as in Astrology.
Each Archetype has a House, but rarely appears in it’s own house. So, symbol 16 “Desire” may align with the House of “Health” or “Profit”.
Further information about Eglash’s Journay in Africa, can be found here:
Bamana Sand Divination: Recursion in Ethnomathematics
This may explain in part some of the strange symbols I have been seeing in cave art recently.
Could Mesolithic peoples have had a complex system of mathematics?
Mathematics deals with patterns, and the patterns I have seen in places like Lascoix suggests they have an equivalent.
Something like this perhaps Alex?
I don’t know to be honest, I noted images in your post that looked like patterns I saw in the Lascoix cave art. As the method you mentioned deals with initiation, archetypes, divination and is african, there may be a similar form at Lascoix.
How cool is that?! I knew of many divinatory systems, but not of sand one! Thank you for sharing!