Continue our look at the earth's crust
Discussed last time how crust is composed of 2 types of rocks
Basalt and Granite
Understanding the WHY and HOW of this has been a problem since the beginning of geological studies
Introduce concept of plate tectonics
Crust is not rigid, but broken into sections, called "plates"
These are moving around on top of the mantle
Plate boundaries are the site of most global tectonic processes and events (earthquakes, volcanos, etc.)
Development of the theory was hard in coming
Anybody here ever have a good idea?
The idea that the earth's crust is not completely stable is not new
As far back as 1620, Sir Francis Bacon noted the similarity of the coastlines of Africa and South America
1658 - François Placet agreed with Bacon
Proposed that they were "Separated in the Biblical flood"
Mid-1800's: Antonio Snider-Pelligrini
Similar fossil plants in coal beds of Europe and North America
Reconstructed a 'supercontinent'
1908 - Taylor & Baker
Correlation of global mountain chains
All these early ideas were pretty casual
And ran counter to existing dogma: Continents permanent and fixed
Alfred Wegener - 1910
Instructor of Meteorology
Noted trans-Atlantic similarities - seems everyone started here
And took note of the observations of earlier workers
1915 - published his theory of Continental Drift with supporting evidence
Basically said that the continents had been joined into a supercontinent he called "Pangea"
Split apart in the Jurassic along what is now the Atlantic Ocean
Initial response less than overwhelming
Developed into a full fledged battle by 1924
R.T. Chamberlain (American) - "Can we call geology a science when there exists such differences of opinion on fundamental matters as to make it possible for such a theory as this to run wild."
Baily Willis (American, 1944) - Wegener's theory is a fairly tale and should be ignored due to its deleterious effect on students
Wegener was an easy target
Just a weatherman - not an "expert" in any of the fields he was leaning on for support
Easy for opponents to pick holes in specifics
Same old regional vs. local problem
I'm sure Wegener would have loved Strickler's 1st Law of GeoFantasy
In any event, his opponents severely took him to task!
They stirred up a Religious fervor against his work
200 years earlier he would have been toast
They plead for "open-mindedness"
They claimed to be the guardians of the truth against idiotic speculation
Pointed to the lack of a mechanism
Sufficient deficiency to significantly discount Wegener's work
Wegener did have supporters
Carried on his work after he disappeared in 1930