Its overall appearance is reminiscent of the comic book character "X-Men" insignia (a cross within a circle); less recently, of a religious symbol. Wikipedia's article on religious symbols provided the first pointer (below right) but symbols.com provided clear confirmation of this symbol's place within our overall field of investigation:
The wheel cross, sun cross, Odin's cross or Woden's cross. Nordic Odin and Teutonic Wotan or Woden was the supreme god of the Nordic religion before Christianity. Odin was the god of art, culture, warfare, and the dead; depicted as an old, one-eyed man with two ravens as his intelligence agents and messengers.
The structure is one of the first non-pictorial graphs to appear when humankind was on the threshold of the Bronze Age. It is common on rock carvings. It appears in ancient Egypt, China, pre-Columbian America, and the Near East. From the facts available it seems as if is associated with the wheel, not so much with its invention as with its revolutionary effect on the existing society. In ancient China this sign was associated with thunder, power, energy, head, and respect.
This figure is also known as the gamma cross, as the Greek letter 'gamma' appears four times within the circle, radially rotated. It is shown to play a prominent role in the Norse, Egyptian, Chinese, and pre-Columbian culture. Perhaps excepting the Egyptian, this observation is consistent with our thesis that the religion of these cultures is based on representations the Tree of Life.
The sun cross embodies several notable features: the circle, the right angle, the line segment, and the point. These figures are all associated with measurement, surveying, mathematics, Platonic geometry, and Freemasonry. Another feature is the fact that the sun cross can be reassembled into the Ankh cross, by remaking the Greek cross into a Tau cross, and placing the circle atop.
Crichton Miller's research on the Celtic cross convincingly demonstrates its use in antiquity as an instrument of spherical/nautical navigation based on the impeccably-supported theory that working models of the true Celtic cross embody a weighted rotating wheel. as the circular portion. Moreover, the Celtic cross was used as a tool of determining longitude and latitude. That Wotan's wheel cross and the Celtic cross bear both a figurative and literal resemblance is worthy of remark.