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 southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring countri ...
and an early supporter of
Alfred Wegener
Alfred Lothar Wegener (; ; 1 November 1880 – November 1930) was a German climatologist, geologist, geophysicist, meteorologist, and polar researcher.
During his lifetime he was primarily known for his achievements in meteorology and ...
's theory of
continental drift
Continental drift is the hypothesis that the Earth's continents have moved over geologic time relative to each other, thus appearing to have "drifted" across the ocean bed. The idea of continental drift has been subsumed into the science of pla ...
.
Early life and education
Du Toit was born in
Newlands, Cape Town
Newlands (Nuweland) is an upmarket suburb of Cape Town, South Africa.
It is located at the foot of Table Mountain in the Southern Suburbs of Cape Town, and is the wettest suburb in South Africa due to its high winter rainfall. The neighborhood ...
in 1878, and educated at the
Diocesan College
The Diocesan College (commonly known as Bishops) is a private, English medium, boarding and day high school for boys situated in the suburb of Rondebosch in Cape Town in the Western Cape province of South Africa. The school was established on ...
in
Rondebosch
Rondebosch is one of the Southern Suburbs of Cape Town, South Africa. It is primarily a residential suburb, with shopping and business districts as well as the main campus of the University of Cape Town.
History
Four years after the first Dutch s ...
and the
University of the Cape of Good Hope
The University of the Cape of Good Hope, renamed the University of South Africa in 1916, was created when the Molteno government passed Act 16 of 1873 in the Cape of Good Hope Parliament. Modelled on the University of London, it offered examinati ...
. Encouraged by his grandfather, Captain Alexander Logie, he graduated in 1899 in
mining engineering
Mining in the engineering discipline is the extraction of minerals from underneath, open pit, above or on the ground. Mining engineering is associated with many other disciplines, such as mineral processing, exploration, excavation, geology, and ...
at the
Royal Technical College
The Royal College of Science and Technology was a higher education college that existed in Glasgow, Scotland between 1887 and 1964, and is the predecessor institution of the University of Strathclyde. Its main building on George Street now serve ...
in
Glasgow
Glasgow ( ; sco, Glesca or ; gd, Glaschu ) is the most populous city in Scotland and the fourth-most populous city in the United Kingdom, as well as being the 27th largest city by population in Europe. In 2020, it had an estimated popul ...
. After a short period studying geology at the
Royal College of Science
The Royal College of Science was a higher education institution located in South Kensington; it was a constituent college of Imperial College London from 1907 until it was wholly absorbed by Imperial in 2002. Still to this day, graduates from th ...
in London, he returned to Glasgow to lecture in geology, mining and surveying at the
University of Glasgow
, image = UofG Coat of Arms.png
, image_size = 150px
, caption = Coat of arms
Flag
, latin_name = Universitas Glasguensis
, motto = la, Via, Veritas, Vita
, ...
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 !Orakobab or Khoemana word ''ǃ’Aukarob'' "Hardveld") is a semi-desert natural region of South Africa. No exact definition of what constitutes the Karoo is available, so its ext ...
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-grained ...
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 (Afrikaans: Drakensberge, Zulu: uKhahlambha, Sotho: Maluti) is the eastern portion of the Great Escarpment, which encloses the central Southern African plateau. The Great Escarpment reaches its greatest elevation – within th ...
. He worked at a furious rate but was known for his painstaking meticulousness, as reflected in his 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
De Beers Group is an international corporation that specializes in diamond mining, diamond exploitation, diamond retail, diamond trading and industrial diamond manufacturing sectors. The company is active in open-pit, large-scale alluvial and ...
until his retirement in 1941.
In 1923, he received a
grant
Grant or Grants may refer to:
Places
*Grant County (disambiguation)
Australia
* Grant, Queensland, a locality in the Barcaldine Region, Queensland, Australia
United Kingdom
*Castle Grant
United States
* Grant, Alabama
*Grant, Inyo County, C ...
from the
Carnegie Institution of Washington
The Carnegie Institution of Washington (the organization's legal name), known also for public purposes as the Carnegie Institution for Science (CIS), is an organization in the United States established to fund and perform scientific research. Th ...
, and used this to travel to eastern South America to study the geology of Argentina,
Paraguay
Paraguay (; ), officially the Republic of Paraguay ( es, República del Paraguay, links=no; gn, Tavakuairetã Paraguái, links=si), is a landlocked country in South America. It is bordered by Argentina to the south and southwest, Brazil to th ...
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 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: lithostra ...
and
radioisotope
A radionuclide (radioactive nuclide, radioisotope or radioactive isotope) is a nuclide that has excess nuclear energy, making it unstable. This excess energy can be used in one of three ways: emitted from the nucleus as gamma radiation; transferr ...
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 ( el, Τηθύς ''Tēthús''), also called the Tethys Sea or the Neo-Tethys, was a prehistoric ocean that covered most of the Earth during much of the Mesozoic Era and early Cenozoic Era, located between the ancient continents ...
, a
northern/
equator
The equator is a circle of latitude, about in circumference, that divides Earth into the Northern and Southern hemispheres. It is an imaginary line located at 0 degrees latitude, halfway between the North and South poles. The term can als ...
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 Pan ...
and a
southern/
polar
Polar may refer to:
Geography
Polar may refer to:
* Geographical pole, either of two fixed points on the surface of a rotating body or planet, at 90 degrees from the equator, based on the axis around which a body rotates
* Polar climate, the c ...
Gondwanaland
Gondwana () was a large landmass, often referred to as a supercontinent, that formed during the late Neoproterozoic (about 550 million years ago) and began to break up during the Jurassic period (about 180 million years ago). The final stages ...
.
Awards and honours
In 1933, du Toit was awarded the
Murchison Medal
The Murchison Medal is an academic award established by Roderick Murchison, who died in 1871. First awarded in 1873, it is normally given to people who have made a significant contribution to geology by means of a substantial body of research and ...
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 judges 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
The Geological Society of South Africa (GSSA) is a learned society for geological science that was founded in 1895, making it one of the oldest such societies in Africa. The GSSA publishes the peer-reviewed scientific journal, the ''South Afri ...
inaugurated a biennial lecture series in his honour that continues to the present day.
In 1973, a 75 km
crater on
Mars
Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, only being larger than Mercury (planet), Mercury. In the English language, Mars is named for the Mars (mythology), Roman god of war. Mars is a terr ...
(71.8°S, 49.7°W) was named "Du Toit" in recognition of his work.
Du Toit crater
Google Mars
Google Earth is a computer program that renders a 3D computer graphics, 3D representation of Earth based primarily on satellite imagery. The program maps the Earth by superimposition, superimposing satellite images, aerial photography, and geog ...
, 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 is a public university in Bowling Green, Kentucky. It was founded by the Commonwealth of Kentucky in 1906, though its roots reach back a quarter-century earlier. It operates regional campuses in Glasgow, Elizabethtow ...
)
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, Gauteng, South Africa, about 50 km west of Johannes ...
)
Alexander du Toit papers and letters archive
(University of Cape Town
The University of Cape Town (UCT) ( af, Universiteit van Kaapstad, xh, Yunibesithi ya yaseKapa) is a public research university in Cape Town, South Africa. Established in 1829 as the South African College, it was granted full university statu ...
)
{{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