His features contort with obvious pain as he tells his story, his memories of Caroline clearly something he holds precious.
What makes the bolded section dependent? What's it missing to form a clause. Is it a type of supplemental clause.?
His features contort with obvious pain as he tells his story, his memories of Caroline clearly something he holds precious.
What makes the bolded section dependent? What's it missing to form a clause. Is it a type of supplemental clause.?
his memories of Caroline clearly something he holds precious
Thus phrase is a nominative absolute (see Wikipedia). A nominative absolute consists of a noun phrase ("his memories of Caroline") followed by a predicate, which here is also a noun phrase ("something he holds precious"); here it is modified by the adverb "clearly."
A nominative absolute essentially serves as a parenthetical remark that contextualizes or explains the rest of the sentence. To turn it into a separate sentence, we would need to add in a finite form of to be:
His memories of Caroline are clearly something he holds precious.
The dependent clause is not a clause at all. The subject of the phrase is not taking any action. To consider if something is a clause, try to separate it out from the rest of the sentence and see if it makes sense as a sentence. "His memories of Caroline clearly something he holds precious," doesn't make any sense because the phrase contains an apparent subject "memories" but lacks a verb.
Rather, the part after the comma is just a plain old phrase and serves to elaborate on the sentence's primary clause. This construction is relatively uncommon in English. Consider similar sentences like, "He crept, afraid that his pursuers may spot him, to the place he had been told was safe," or, "Fed up with their behavior, she slammed the encyclopedia down on the table." These two sentences use a phrase for elaboration in the same way as your example sentence, though both place the elaborating phrase in different places of the sentence than your example.