Center entire markup block

[Christopher Meredith]

I have a couple of markup blocks which are currently left aligned
which I would like to be centered on the page. The following snippet
is the section in question and it contains solutions from the LSR as
well as other projects. In other words, I know it works but I don't
know exactly how.

http://pastebin.com/FTinRLWx

I've tried everything I can think of. Can someone point out what I
would need to do to center this? Thanks.