Thanks for your insight Lar. I am trying to understand the meaning of your "rind" analogy. Are you suggesting that there is a pronounced diorite cap on the newly exposed surface at the 88 zones that has been (presumably) eroded away at T1? How would we know whether erosion had previously occurred at 88 (or not) prior to the emplacement of the current sediments/overburden?

Looking forward to seeing you at the show,

Scott