The Earth Mother is always chthonic and is occasionally related to the moon, either through the blood-sacrifice already mentioned, or through a child-sacrifice, or else because she is adorned with a sickle moon.
Jung defines the Earth Mother’s essential character as chthonic and lunar, identified by dark or red colouration, archaic bodily form, and ritual blood association.
, The Archetypes and the Collective Unconscious, 1959thesis