April 21. Terminology -- a short rant

Today is a break from the Silurian, and a bit of a rant on my part but one that I hope is informative for you. When we recently talked about the Caledonian Orogeny, I mentioned that it is sometimes called the Acadian Orogeny in the United States. That’s just one source of potential confusion caused by geologists using different names for the same thing. I know I’ve been guilty of it too – it’s hard to put hard and fast names to things that happen over millions of years, and over somewhat different millions of years in one place versus another. Some geologists would call the Taconic Orogeny one of the early phases of the Caledonian. And the Caledonian itself might be considered to be the start of an even grander development that could be called the Appalachian Orogeny – but if we do, then the Appalachian Orogeny lasted at least 150 or 200 million years. To have reasonable conversations, you have to subdivide that into discrete parts – for the sake of discussion, if nothing else.

Still, it can be frustrating to me – and certainly to you – if I use one word for a geological event here and a different word there. Some geologists will use different names to refer to a location – Caledonian in Europe, Acadian in North America, when the cause was the same geologic process. And other geologists might use the term Caledonian to refer to something going on in China at the same time, Silurian, as the events in Europe and America, when there’s no connection to speak of in terms of events.

Sometimes there’s a style to the mountain building events – it might be one involving intense brittle deformation, breaking the continent into big blocks, or it might be more of a matter of pushing some rocks up and over other rocks. Sometimes geologists will call one style one name and the other another – and those names might be the same as the names others use for a particular place or a particular time. It can most definitely get confusing.

My goal with these podcasts is to provide technical information about earth history in an interesting and understandable way, so I will be trying diligently to avoid these sorts of pitfalls. But be aware that they are out there, part of the nature of science, and I might do it sometimes too. Please don’t hesitate to inquire, by way of a comment on the blog, or send me an email at rigibson@earthlink.net. I’ll try to clear up any confusion that I cause.

—Richard I. Gibson