The Blade – vertical beds of sandstone

Gustave-Émile Haug. Now, there’s a name you don’t hear everyday. Unless you specialize in the obscure. But everyone has a birthday, today would have been Haug’s, so let us remember the French geologist for his role in helping to develop the failed geosynclinal theory of mountain building. Born in 1861, his 1907 Traité de géologie was “an invaluable reference” to those who valued it. It spoke of the way seaside synclines – actually massive trenches – fill with continental sedimentary runoff, then mysteriously rebound as mountain ranges. Haug’s playground was the Provence Region of the Alps. This photograph of the 50-metre inclined  sandstone blade, variously known as the Lame (Blade) de Facibelle or L’homme (The Man) de Tanaron is emblematic of Haug’s research. It is as near to 90 degrees and as well-exposed as one might ever hope to see a synclinal structure. Haug worked this landmark into his Treatise of Geology and the old blade has been part of geological story-telling ever since.

The Americans originally developed the idea of geosynclines as the forging pit for mountains. It became the early-20th-century’s best solution to the problem of mountains.  Contraction, the more popular idea of mountain-formation as a result of Earth’s cooling and shrinking, did not have many followers in America. Instead, geosynclinal rebound was the American answer to mountain existence. The idea was that eroded material accumulated in offshore trenches to enormous thicknesses. Some calculated that the thickness of sediment passed 12,000 metres. Geologists assumed that heat and pressure forced the material to eventually rebound as mountains – like toothpaste squeezed from a tube.

One of the main champions of this idea was James Dana, head of geology at Yale for 42 years. Dana had a stellar career. He graduated from Yale at age 20. By 24, he had written a 1,430-page crystallography and mineralogy book, System of Mineralogy. That was in 1837. Until Dana, no one had ever written such an in-depth analysis of the shapes, sides, angles, and facets of mineral crystals. Tackling the geometry that describes crystallography is daunting. It is not a science for the timid. Dana’s geology was brilliant. Almost everything geological caught his attention. His last paper, written in his 70s involved volcanology.

This mountain-building theory of Dana, built upon by Haug and others, was a clever idea and gathered advocates who were rather certain the idea would work. It had followers well into the 20th century – most Americans dismissed Wegener’s drift idea and championed geosynclinal theory instead. It was a convincing theory. A good idea. Mountains, somehow rising from the destruction of continents. But it had a major weakness. There were no known examples of geosynclinal mountain-building at work anywhere in the world. Ultimately, it gave way to plate tectonics as the explanation for mountain building.

Read the book,  The Mountain Mystery.