Brownlands is a term used for lands changed by contact with the earthen aspects of Granitoid. The Brownlands are unstable and subject to change with very little warning. The source of this instability comes from things like the Earth Callers and the Togomud Sink.
The Greenland Alliance blames Geb for the landscaping of Gebs Chosen and Rilirthad; their master plan to terraform the world around them. As such, the Greenland Alliance mockingly refers to the Brownlands as Geb's Stain.
The Brownlands are an aspect of the Karnegmoth Cataclysm.