Google Structured Data Issues

I noticed recently that in Google SERPS, my photo isn’t showing up next to my posts even though I have the site linked to my Google+ account.

I’ve checked the Structured Data page and it says there are 383 items with errors:

* 383 due to ‘Missing: updated’
* 6 due to ‘Missing: author’

I’ve tried looking at the error information, but I’ve no idea what the correct info should be, so there’s no way for me to tell what’s incorrect.

It looks like it’s a site-wide problem, so I’m not sure if it’s a plugin issue, theme issue or something else.

Site is http://scavenger-hunt.org/