One item that popped into mind when thinking about Uniformitarianism vs Catastrophism was the preceding debate over the origin of the Earth's crust and its variations of bedrock (IG, SED, META). Neptunism vs Plutonism was a classic geologic debate that showed the value of field work and how direct evidence gathered from it strengthens a hypothesis. Geology and its various branches literally just don't work without field study.
|Abraham Gottlob Werner|
So although initially received with great interest and enthusiasm, Werner's ideas soon drew criticism for failing not only to properly explain many features of plutonic & volcanic origin (see below), but what had become of the immense volume of water that once covered the Earth to a depth so great that all continents were totally inundated. The amount locked in continental & alpine glaciers in the late 1700's was not sufficient explanation, given knowledge of the cryosphere in the 18th century, and the topography of the ocean floor was barely mapped (it wouldn't explain it anyways). Neptunism had to pooh-pooh anything to do with volcanism, and some of the ideas bandied about were absurd even for the day. I once read that volcanoes were vents for the expulsion of burning plant matter (coal) from within the Earth; essentially they were labeled by Neptunists as cone-shaped barbecues.
|Various volcanic features and forms, |
most of which were unexplained or
dismissed by Neptunists
Debate is good for the evolution of a scientific discipline, and though today's debates in geological academia are of a different flavor than the one I've just focused this post on, they are just as important in furthering our understanding of the spheres of our natural world, an understanding that I hope never comes to a completion. If anyone wants to check out some quoted material from early Plutonists, look no further than this page which has explanations of fractionation & igneous differentiation by English geologist George Poulett Scroupe.