Please add example games/lines, or referances to books/articles to support your opinion if possible.

Hiya, the title says it all.  I'm looking examples of white playing a d5 pawn thrust in the caro-kann pawn structure, and reasons why he would do it.  I'm also curious to know what the preconditions are (Must white have already played c4 for example)

I would guess the point is to either trade off the somewhat weak d pawn (c3 is the only way to defend it with pawns, and that's awkward), or to open files when blacks pieces/king is vulnerable.

Eric: Thank you for summerizing all the reasons why I thought white would never play d5 =).  But unfortunately he occasionally does, and I'm no closer to figuring out why =(.

Um, how exactly does White gain control of the d5 square in the Caro-Kann in the first place? I suppose in the mainline, after 3. dxe4 by Black, White could gain control of d5.

White controlling d5 could come in handy in a specific position, but by the looks of the opening, I doubt if that's very useful most of the time. White doesn't gain much space or open new lines of development. Moreover, the d-pawn isn't weak since it is still connected to the larger island of Queenside pawns. It's not like the Tarrasch where you have an isolated Queen pawn.

Black has firm control of the d5 square with c6, Queen on the file, and Nf6. I think that's kind of the point of the opening.