Something that has not been mentioned are intrusions. Intrusions are very much a part of geologic columns worldwide.
Indeed, I don't think that igneous intrusives and metamorphic rock have ever much been covered at . BUT, I think such areas of geology are rather remote to the real theme of this topic. They are seemingly doomed to be lost in "yet another geological column topic".
Perhaps roxrkool could propose a new "Igneous and Metamorphic Rocks" topic, before such discussion goes to far in this topic. If so, please link back to a good spot in this topic.
The non-admin mode is too feeble to himself pull off starting the topic.
New Members should start HERE to get an understanding of what makes great posts.
Re: Need a new "Igneous and Metamorphic Rocks" topic
I think that "Geologic Column" topics have rightly been intended to be focused on the themes of sedimentation and stratigraphy. I find no problem with including volcanism (eg. Siberian Traps and other) in this.
Certainly, all of the Earth's geology ties together. Igneous and metamorphic rocks can be part of the discussion.
But I think that the more specific other aspects of the Earth's composition and structure are deserving of having their own more specific topics. This would include such things as stress/strain analysis of folding and faulting, and such things as igneous and metamorphic petrology.
Why a pegamite is very coarse grained, and why an obsidian is glass does not belong in a sedimentation and stratigraphy topic. Why you get the various grades of contact and regional metamophism do not belong in a sedimentation and stratigraphy topic. They are wothy of their own topics.