"Graham has chosen to refer to this forgotten genesis of humanity’s extended link with the cosmos as the “lost civilisation,” something reflected in the title of his book. Greg and I refer to it as the “shamanic civilisation,” since it is not so much a civilisation of roads, rivers, city states and writing, but one of a universal expanded mindset reflected in religious and magical ideas and practices, along with the building and design of geometric, liminal structures, and a universal cosmic journey of the soul centred around a perceived place of origin and place in the afterlife among the stars."
So, you are suggesting that "shamanism" may have been The unifying impetus?
Do you envision gatherings based on getting high on substances then? The way shamisim gets thrown around these days, maybe fuller clarification would be a good idea.