Blix again – help needed on archives

I have nearly finished customizing the Blix theme on my WP blog (www.bioteka.lv), and there is one last issue remaining that I can’t seem to solve myself.

When I press Archives by month OR Categories (with some subcategories), I get the posts that were created on that month or in that category. However, I get full post text. If I have dozens of posts, the page gets really long!

What I need to change so that I would get only the excerpts (created with more tag) instead + Read more option (just like on first page)?

Hope there are any Blix fans out there who can help with advise. Thank you!