Extensive stratified deposits of very fine grained, highly plastic blue clay are reported to occur on the north shore of the Fraser River, opposite Seabird Island. In general, this blue clay cracks badly in drying and has a very short firing range. However, this type of clay was used successfully for many years by the Port Haney Brick Company, particularly for the manufacture of structural and drain tile.

Analysis of the same type of clay from the Haney area yielded 58.5 per cent SiO2, 21 per cent Al2O3, 8.6 per cent Fe2O3, 6.5 per cent CaO, 0.5 per cent MgO, 46 per cent water and 4.8 per cent ignition loss.