In short, Armitage pioneered research (see: Journal of the British Interplanetary Society, vol. 30, pp. 466-9, 1976) that was quite nearly lost to the sands of time until rescued by Steve Wilson and posted on his blog. The research included a breakdown of hypothetical astro-paleontology considerations that admittedly overlap xenoarchaeology and were decades ahead of their time, (directly overlapping research I’m currently pursuing.)
Be sure the check out both the Space Archaeology posts.
(Simply being able to rebroadcast information like this is proof to me of the infinite utility of our global information superstructure! One person can now make a discovery, which can trickle outward through the internet as post/page/tweet dominos…)
Amongst the more interesting contents of the 1976 paper is Armitage’s proposition of a discretized “remains” continuum. With it, he essentially breaks down what planetary and interstellar explorers could expect to find and what consequent mode of study or detection the remains would require. Specifically, I suggest that his proposed differences between “metazoan grade (non-intelligent)” and “metazoan grade (intelligent)” are deserving of the greatest renewed investigation or development, as our concept of intelligence is quite arbitrary here on Earth where the differences between “archaeology,” “anthropology,” “biology,” and, “paleontology” are concerned.
Food for thought.