This post from Near Emmaus contains an intriguing reference to the work of J. G. Crossley who dates the writing of the Gospel of Mark in the 40’s C.E. The context is a notice about a new Craig Evans’ book on the Gospel of Matthew.
This leads [Dr. Craig A. Evans] to mention the work of J.G. Crossley who dates the Gospel of Mark to the 40′s. He proposes that it is possible that the Evangelist used Mark since it may have been in circulation for about twenty years already. As a side note he mentions that the Book of Acts ends rather abruptly with the narrative coming “to an end no later that 62 A.D., before the death of James, the brother of the Lord.” (p. 5) Since Acts follows Luke this leads to the proposal that, “…we see reasonable arguments for the writing and circulation of all three Synoptic Gospels sometime prior to the war of 66-70 A.D.” This is quite the claim!