Welcome codemon. I recognise the argumentative manoeuvre you describe. It is not a fallacy since there is no strict error in reasoning (as e.g. in 'If p then q; q; therefore p - the fallacy of affirming the consequent) but it is intellectually sub-standard.
It is close to the argumentum ad verecundiam, appeal to authority. Though I don't agree that the appeal to authority is necessarily fallacious or in any other way objectionable since the authority appealed to may be as reliable at one can get in the present state of knowledge. Whatever else it may be, it is not fallacious to appeal to Einstein as a relevant authority when I claim that E = MC-squared.
In contrast, it is a dubious procedure when I say something such as:
Google it. I'm not going to do your homework for you.
Two things are wrong : (1) Google is not an authority in the way in which an Ivy League paleontologist is [unproved authority]; and (2) precisely where in Google am I to find the most reliable information [vague appeal]? (1) and (2) combine in what one might term a vague appeal to unproved authority. I'm sure there's a better label but this might serve for the present.