See AmMin's special collections at http://ammin.geoscienceworld.org/site/misc/specialissuelist.xhtml. Special collection papers are identified in each issue by a specific heading and footnote in the issue of publication, as well as on the Table of Contents. Additionally, the GSW site has a classification tag found on the right-hand side of the article that is a link to all the collection papers.
Authors, submit your paper as normal (http://minsocam.allentrack.net). In the screen asking about Special Collections, please select from the pull-down menu. The help on that screen provides details about open collections and invitation only (you can always correspond with the special collection associate editor if need be). [Associate Editor contact data is available via http://www.minsocam.org/MSA/AmMin/aes/aelist.html (on the main MSA web site).]
To propose a special collection please contact Editor Keith D. Putirka.
All special collection papers go through the same peer review and editorial process as any other paper. They are published when ready and not held up waiting for other papers to finish. Instead the collection also grows virtually over time via the web. The virtual collection (as it grows) will be available for easy selection of papers and each year collections that have a "quorum" are available via MinPubs as a course packet or for other uses.
Our special collection Associate Editors: