Please look at these two sentences:
- It is serene, this piece of the Old World.
- Word has reached my ears of this Aragorn, son of Arathorn, and I tell you now, I will not bow to this Ranger from the North, last of a ragged house long bereft of lordship! (LOTR)
In sentence 1, the phrase "this piece of the Old World" is the deferred subject of the anticipatory "It".
In sentence 2, "last of a ragged house long bereft of lordship" modifies "this Ranger from the North".
In both cases, the phrases do not contain a non-finite verb or a preposition. What kind of construction is it? Sentence 1 is very close to a cleft sentence, but in the reference material there is not a single example where a phrase has been used separated from the main clause by a comma. They are all subordinate clauses.
Could someone clarify what kind of construction this is?
Edit: Reading the comments, I think it is safe to assume that appositives can take the place of subordinate clauses which act as a delayed subject. These are both appositives, then, serving different functions?