A few blog owners become concerned about how their blogs are indexed - and why the search hit lists, that point to their posts, point to archive or main pages - instead of the individual post pages.
"www.mydomain.com/2015_01_01_archive.html" , "www.mydomain.com/2014_12_01_archive.html", and similar URLs are part of the same URL structure as "www.mydomain.com" - and as "www.mydomain.com/2015/02/whatever.html". They aren't harmful to the blog search engine reputation.
They are annoying, though. When I setup this blog, long ago - and would find my posts listed in index pages, they used to annoy me, too.
Archive and main page indexing is a normal result of Blogger blog structure.
If you publish your blog, with the complete post visible on the main page, the complete post will also be visible on an archive index page.
People will read your blog - and read the posts - from the main page. And search engines will index the blog, from the main page content.
As the posts get old, and newer posts displace older posts into the archive pages, the posts get indexed as part of the archive pages.
The archive and main pages contain multiple posts, so they are larger - and they have more weight with the search engines. More weight makes main and archive indexes show up ahead of, or instead of, the individual post pages, in a search hit list.
The answer, to that confusion, is to use Jump Break. Make your readers click once, to read a complete article.
The search engines will index less content on main and archive pages - and more content on the post pages. And the post pages will come in ahead of, or instead of, archive and main page indexes.
Also, if you want your blog read reliably, add search descriptions to the blog and to the posts, to attract more readers from the search engine result lists.
An Important Update
If you did not use a Blogger / Google account when you Followed this blog, years ago, you are probably not Following now . During the past...