Turton means "Thor/Þor's village", from the Old Norse personal name Thor/Þor and Old Englishtun "farm, village". It was recorded as Thirtun in 1185Billington, W.D. (1982). From Affetside to Yarrow : Bolton place names and their history, Ross Anderson Publications (ISBN 0-86360-003-4).
The Scandinavian etymology would seem to fit, considering that there are other place-names in the area of this origin.