Off-the-cuff analysis:
"The Lord of the Rings" is Fourth Turning - huge war, big changes, nothing quite the same after.
"The Hobbit" is Third Turning - individuals in search of riches, minimal government initiative, notable wars that don't much change the balance of power, and minor subplots that later turn out to be a much bigger deal.
Haven't read "The Silmarillion" although it sounds like it covers a couple of them, perhaps a Golden Age First Turning corrupted by Sauron leading to the rebellious attempt by Men to set foot on the lands to the West. But don't quote me in that.
