James Crossley offers an interesting glimpse into his scheme for dating the Gospels.
While I like his radically early dating of Mark (late 30s CE!), I feel that that’s a bit too early. I do think, however, that the predictions in Mark 9:1 and 13:30 place this document before 70 CE and the destruction of the Temple.
Dating these things is always a bit of a mind puzzle—evidence X jives with theory Y, but evidence Z does not. What to do? Do your best, I guess.