Alexander Logie du Toit FRS ( ; 14 March 1878 – 25 February 1948) was a geologist from

South Africa South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. Its Provinces of South Africa, nine provinces are bounded to the south by of coastline that stretches along the Atlantic O ...

and an early supporter of Alfred Wegener's theory of

continental drift Continental drift is a highly supported scientific theory, originating in the early 20th century, that Earth's continents move or drift relative to each other over geologic time. The theory of continental drift has since been validated and inc ...

Early life and education

Du Toit was born in Newlands, Cape Town in 1878, and educated at the Diocesan College in Rondebosch and the University of the Cape of Good Hope. Encouraged by his grandfather, Captain Alexander Logie, he graduated in 1899 in

mining engineering Mining engineering is the extraction of minerals from the ground. It is associated with many other disciplines, such as mineral processing, exploration, excavation, geology, metallurgy, geotechnical engineering and surveying. A mining engineer m ...

at the Royal Technical College in

Glasgow Glasgow is the Cities of Scotland, most populous city in Scotland, located on the banks of the River Clyde in Strathclyde, west central Scotland. It is the List of cities in the United Kingdom, third-most-populous city in the United Kingdom ...

. After a short period studying geology at the Royal College of Science in London, he returned to Glasgow to lecture in geology, mining and surveying at the

University of Glasgow The University of Glasgow (abbreviated as ''Glas.'' in Post-nominal letters, post-nominals; ) is a Public university, public research university in Glasgow, Scotland. Founded by papal bull in , it is the List of oldest universities in continuous ...

and the Royal Technical College.

Career

In 1903, du Toit was appointed as a geologist within the Geological Commission of the Cape of Good Hope, and he began to develop an extensive knowledge of the geology of southern Africa by mapping large portions of the

Karoo The Karoo ( ; from the Afrikaans borrowing of the South Khoekhoe Khoemana (also known as !Orakobab or Korana) word is a semidesert natural region of South Africa. No exact definition of what constitutes the Karoo is available, so its extent is ...

and its

dolerite Diabase (), also called dolerite () or microgabbro, is a mafic, holocrystalline, subvolcanic rock equivalent to volcanic basalt or plutonic gabbro. Diabase dikes and sills are typically shallow intrusive bodies and often exhibit fine-grain ...

intrusions, publishing numerous papers on the subject. Subsequently, he mapped the entire Karoo System through the complete stratigraphy from Dwyka

tillite image:Geschiebemergel.JPG, Closeup of glacial till. Note that the larger grains (pebbles and gravel) in the till are completely surrounded by the matrix of finer material (silt and sand), and this characteristic, known as ''matrix support'', is d ...

to the

basalt Basalt (; ) is an aphanite, aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the planetary surface, surface of a terrestrial ...

of the

Drakensberg The Drakensberg (Zulu language, Zulu: uKhahlamba, Sotho language, Sotho: Maloti, Afrikaans: Drakensberge) is the eastern portion of the Great Escarpment, Southern Africa, Great Escarpment, which encloses the central South Africa#Geography, Sout ...

. He worked at a furious rate but was known for his painstaking meticulousness, as reflected in his 1937 book ''Our Wandering Continents''. It still bears reading for its creative and closely argued theses in the light of the geology of the day, and is soberingly consistent with modern principles of plate tectonics. In 1920, du Toit joined the Union Irrigation Department as water geologist, and in 1927, he became chief consulting geologist to De Beers Consolidated Mines until his retirement in 1941. In 1923, he received a grant from the

Carnegie Institution of Washington The Carnegie Institution for Science, also known as Carnegie Science and the Carnegie Institution of Washington, is an organization established to fund and perform scientific research in the United States. This institution is headquartered in W ...

, and used this to travel to eastern South America to study the geology of Argentina,

Paraguay Paraguay, officially the Republic of Paraguay, is a landlocked country in South America. It is bordered by Argentina to the Argentina–Paraguay border, south and southwest, Brazil to the Brazil–Paraguay border, east and northeast, and Boli ...

and Brazil. As is apparent from his remarks in "Our Wandering Continents", he had requested support for the expedition not on a whim but specifically to test his predictions of correspondences between the geology of both continents. In the event, he was able to demonstrate and follow the predicted continuation of specific features that he had already documented in Southern Africa, into the continent of South America. Although it might perhaps seem less impressive to the layman, that evidence was far more convincing to the geologist than was the matching of continental shelves. In the light of his research, du Toit published a review of the

stratigraphic Stratigraphy is a branch of geology concerned with the study of rock layers (strata) and layering (stratification). It is primarily used in the study of sedimentary and layered volcanic rocks. Stratigraphy has three related subfields: lithost ...

and

radioisotope A radionuclide (radioactive nuclide, radioisotope or radioactive isotope) is a nuclide that has excess numbers of either neutrons or protons, giving it excess nuclear energy, and making it unstable. This excess energy can be used in one of three ...

evidence from those regions that supported Wegener's ideas, ''A Geological Comparison of South America with South Africa'' (1927). His best-known publication, ''Our Wandering Continents'' (1937), expanded and improved this work and, departing somewhat from Wegener, proposed two original

supercontinent In geology, a supercontinent is the assembly of most or all of Earth's continent, continental blocks or cratons to form a single large landmass. However, some geologists use a different definition, "a grouping of formerly dispersed continents", ...

s separated by the

Tethys Ocean The Tethys Ocean ( ; ), also called the Tethys Sea or the Neo-Tethys, was a prehistoric ocean during much of the Mesozoic Era and early-mid Cenozoic Era. It was the predecessor to the modern Indian Ocean, the Mediterranean Sea, and the Eurasia ...

, a northern/

equator The equator is the circle of latitude that divides Earth into the Northern Hemisphere, Northern and Southern Hemisphere, Southern Hemispheres of Earth, hemispheres. It is an imaginary line located at 0 degrees latitude, about in circumferen ...

ial

Laurasia Laurasia () was the more northern of two large landmasses that formed part of the Pangaea supercontinent from around ( Mya), the other being Gondwana. It separated from Gondwana (beginning in the late Triassic period) during the breakup of Pa ...

and a southern/ polar Gondwanaland.

Awards and honours

In 1933, du Toit was awarded the Murchison Medal by the

Geological Society of London The Geological Society of London, known commonly as the Geological Society, is a learned society based in the United Kingdom. It is the oldest national geological society in the world and the largest in Europe, with more than 12,000 Fellows. Fe ...

, and in 1943, he became a

Fellow of the Royal Society Fellowship of the Royal Society (FRS, ForMemRS and HonFRS) is an award granted by the Fellows of the Royal Society of London to individuals who have made a "substantial contribution to the improvement of natural science, natural knowledge, incl ...

. In 1949, the year after his death, the Geological Society of South Africa inaugurated a biennial lecture series in his honour that continues to the present day. In 1973, a 75 km

crater A crater is a landform consisting of a hole or depression (geology), depression on a planetary surface, usually caused either by an object hitting the surface, or by geological activity on the planet. A crater has classically been described ...

Mars Mars is the fourth planet from the Sun. It is also known as the "Red Planet", because of its orange-red appearance. Mars is a desert-like rocky planet with a tenuous carbon dioxide () atmosphere. At the average surface level the atmosph ...

(71.8°S, 49.7°W) was named "Du Toit" in recognition of his work.Du Toit crater
Google Mars, retrieved 10 July 2007

Significant works

* du Toit, A.L. (1926) ''The Geology of South Africa'', Oliver & Boyd, London, UK * du Toit, A.L. and Reed, F.R.C. (1927) ''A Geological Comparison of South America with South Africa'', Carnegie Institution of Washington, Washington, USA * du Toit, A.L. (1937) ''Our Wandering Continents; An Hypothesis of Continental Drifting'', Oliver & Boyd, London, UK

References

External links

Biography
(Charles H. Smith,

Western Kentucky University Western Kentucky University (WKU) is a public university in Bowling Green, Kentucky, United States. It was founded by the Commonwealth of Kentucky in 1906, though its roots reach back a few decades earlier. It operates regional campuses in Glas ...

)
Alexander du Toit's map of two ancient supercontinents
(more detail

Hartebeesthoek Radio Astronomy Observatory The Hartebeesthoek Radio Astronomy Observatory (HartRAO) is a radio astronomy observatory, located in a natural bowl of hills at Hartebeesthoek just south of the Magaliesberg mountain range, and about 50 km west of Johannesburg, Gauteng, Sout ...

)
Alexander du Toit papers and letters archive
(

University of Cape Town The University of Cape Town (UCT) (, ) is a public university, public research university in Cape Town, South Africa. Established in 1829 as the South African College, it was granted full university status in 1918, making it the oldest univer ...

) {{DEFAULTSORT:Du Toit, Alexander 1878 births 1948 deaths South African geologists Tectonicists University of Cape Town alumni Alumni of Diocesan College, Cape Town Fellows of the Royal Society Presidents of the South African Archaeological Society Presidents of the Geological Society of South Africa