Custom text in header on posts page

I need to add a custom blockquote-style blurb to the header on our home page, which is a posts page (using a child theme to Mantra).

Our site: http://www.lcnlit.org

Would like to add the blurb below the site title/tagline but above the tabbed navigation.

Thank you for answering this noob question.

via Chebli Mohamed