What punctuation mark separates two independent clauses joined by a conjunctive adverb such as however or furthermore?

The punctuation mark that separates two independent clauses joined by a conjunctive adverb like "however" or "furthermore" is a semicolon (;).

Here's why:

* Independent clauses: These are complete sentences that can stand alone.

* Conjunctive adverbs: These words (like however, furthermore, therefore, etc.) connect two independent clauses and show a relationship between them.

* Semicolon: The semicolon is used to show a stronger separation between the clauses than a comma would provide.

Example:

* Incorrect: The weather was terrible, however, the game went on.

* Correct: The weather was terrible; however, the game went on.

Let me know if you'd like more examples!