punctuation - Using ellipsis to indicate a pause in conversation

Wikipedia has a sentence in its article on ellipsis:

In reported speech, the ellipsis is sometimes used to represent an intentional silence, perhaps indicating irritation, dismay, shock or disgust. This usage is more common amongst younger, Internet-savvy generations.[citation needed]

I can find plenty of random internet articles making a similar statement, but is there an actual authoritative grammar source that says this is grammatically correct? Is it just something the "Internet-savvy generations" have invented?

Here is an example from a story:

She swallowed hard. "I'm afraid, Mark. Maybe if you might... talk to him?"

Here the ellipsis is indicating a verbal hesitation in the quote rather than the typical use of indicating an omission.

Answer

According to Grammar Girl, several style guides support the use of ellipses to indicate a pause (the relevant paragraph can be found under the header The E-mail Ellipsis).

She quotes from the Chicago Manual of Style that "Ellipsis points suggest faltering or fragmented speech accompanied by confusion, insecurity, distress, or uncertainty."

I would consider such style guides to be the kind of authoritative source you were looking for.