Crop of a derivative of Robert Plant's Led Zeppelin sigil of a feather inside a circle, likely a simple merging of two symbols from the "Feather Symbol of Truth" illustration on page 105 of James Churchward's 1933 book The Sacred Symbols of Mu (Churchward died in 1936). The original symbol was used in Led Zeppelin IV.
This file was derived from: Zoso.svg
freakofnurture (derived source); unknown (creator of original)