If this blog had a tagline it would be "an ongoing conversation with myself."
It was an idea formulated by Venkatesh Rao at Ribbon Farm.
An Elder blog is one which has been around for a while and has "significant history" (i.e. a decent amount of content) such that it can be viewed holistically rather than on a per post basis, teasing threads woven into its fabric.
I've described the blog as this ongoing conversation on numerous occasions over the years, often referring to earlier posts but think I fall down on turning those references into full threads, building on previous ideas. I tend to blog more in "batches" with a series of posts on the same topic in quick succession (I've mentioned this before but can't find it) but this isn't really the same as a blog chain.
The elder-blog is a direct contrast to the idea of truly blogging for now where posts are of the moment, disposable.
This blog is now around eleven and a half years old (the first five years of my blogging life have been lost except for scattered instances on the Internet Archive) but it's not quite prime elder-blog real estate yet due to my taking various, often protracted, breaks.
Still, as much as I'm curious about how a "blog for now" would really work (even to the point of removing old posts, just as with tweets) it is the potential for continuity, for themes, and for talking to myself - past and future - that makes the blog what it is.
It's just need to do more of it.