lag is a general term applied to coarse grained (> 2 mm), hard, but partially weathered rockfragments, which are concentrated at the surface through attrition of finer materials. based on morphology,mineralogy and the origin of lag from the cobar region of australia, lag may be conveniently grouped intothree broad morpho-mineralogical categories; (a) those with a rough, blocky, lithic morpholog...