PLATES B: Continental Drift

                       Bullard's best (computerized) fit

This is the second of a series of blogs in which I will describe how I dealt with the birth of the plate tectonics paradigm, which now of course now completely dominates geotectonics.  I was in the perfect place to observe: I was at a major university, studying geology, totally absorbed by it, old enough to be skeptical – and completely ignorant!

Well, the paradigm came about in three installments: continental drift, ocean floor spreading, and finally plate tectonics proper.  I will begin with the initial phase.  

In the late 1950s, at Stanford, here is what some of us were mulling over, concerning drift: the “fit” of the Atlantic-bordering continents, geologic “matches” on either side of that ocean, the Glossopteris flora of what came to be known as Gondwana, and evidence of Permian glaciation in those same Gondwana continents but not elsewhere.  The heroes of this stage were Alexander Dutoit, Sir Edward Bullard, and others:  and of course Alfred Wegener, who initiated the whole thing.

Wegener’s evidence basically consisted of the statement that the fit of continental outlines, as well as geologic and fossil similarities, on Atlantic-bordering continents were to exact  to be coincidental.  For instance: the geology of the Caledonian mountains of northern Europe is an excellent match to the geology of the Appalachian mountains of North America.  Moreover, a peculiar and distinctive fossil flora was known to be present, along with glacial deposits, in Africa, India, South America, and Antarctica – but not elsewhere.  The overwhelming precision of the Bullard fit (shown) should alone have proved the case but, of course, it didn’t.

In the meantime, I was tearing through my elementary classes as quickly as possible, going to all our guest lectures, and reading on my own.  By the time the next stage in the revolution rolled around I was pumped and raring to go!

If you want my guess as to why every geologist of that era didn’t welcome continental drift with open arms and a kiss on the cheek, click on: 

https://frivilousessays.blogspot.com/2020/10/s-warren-carey-part-2.html