$1 authorizations are commonly used by merchants to confirm the validity of a credit card without actually placing a charge on it. Since these are from a week ago, I'm almost certain that this is what they are. If I'm correct, then no charges will actually ever post to your credit card account, and the $1 that's been taken out of your available credit will be restored based on whatever time limit for such things with your bank expires (typically, 1-4 weeks).

When these authorizations were made, were you by chance making a reservation on co.com? I would imagine that it makes a $1 authorization when you place a reservation on hold, in order to prevent people making phantom reservations all day long.