SCUFFING (microseizure)

This type of failure - caused by the local breakdown of oil film as the surfaces slide over each other during mating and disengaging 
With oil film breakdown, very high tempo are generated and welding of local high spots occurs Similar to that occurring with microseizure). These are then torn apart.
It is most prevalent at the tips and the root were relative sliding is at its greatest .

Scuffing is definitely due to failure of the oil film to carry the load, either because the operating conditions are abnormally severe, or because of incorrect oil selection.