This polychromic pictograph is that of an archaic style stupa (Tibetan = chorten) as typified by the small midsection (bumpa), short spire, long streamers and horn-like finale. The counterclockwise swastika (yungdrung) painted in the same red ochre pigment identifies this as a Bon composition. Polychromic rock paintings seem to be rare in Tibet (for reference to another example see my Divine Dyads, p.262, Library of Tibetan Works and Archives: 1997). Probably early Buddhist period to 1300.