 Arkose-hosted SedEx deposits are known in some cases, associated with arkosic strata adjacent to faults which feed heavy brines into the porous sands, filling the matrix with sulfides, or deposited within a predominantly arkosic layer as a distinct chemical sediment layer usually associated with a shale interbed or at the lowermost levels of a shale formation directly overlying arkosic sands (for example, copper deposits near Maun, Botswana).Occasionally, mineralization is developed in faults and feeder conduits which fed the mineralizing system.For instance, the Sullivan orebody in south-eastern British Columbia was developed within an interformational diatreme, caused by overpressuring of a lower sedimentary unit and eruption of the fluids through another unit en route to the seafloor.