(Otto Carl) Siegfried Passarge, German geographer and ethnographer, studied physics, chemistry and geology at the University of Berlin for a year from 1886 with a view to becoming an African explorer. He continued his studies at Freiburg and later at Jena, where he was awarded a doctorate in geology in 1890 and qualified in medicine in 1892. During 1893-1894 he conducted geographical and geological studies in Cameroon, part of which was then a German colony. In 1896 he was approached by the British West Charterland Company to prospect for minerals in the region that is now northern Botswana. After brief visits to the Cape Colony and the South African Republic (Transvaal) he travelled to the Kalahari and studied the region for the next three years. He made observations relating to the physical geography, climate and inhabitants of the region, did geological mapping, and collected some plants. As a result of his sound academic background and influential publications he can be regarded as the pioneer earth scientist of the Kalahari.
Passarge's physiographic description of the Kalahari, Die Kalahari: versuch einer physisch-geographischen Darstellung der Sandfelder des suedafrikanischen Beckens (Berlin, 1904, 2 vols), became a classic. He was the first to classify the Kalahari sands and other young deposits as a distinct geological succession, which he called the Kalahari System (now the Kalahari Group). From his observations on these deposits and the geomorphological features of the region he deduced the climatic changes that had occurred during the Tertiary and later periods. His map in a paper on the Okavango swampland and its inhabitants (1905) added important information on the river system of the Okavango, showing for the first time the vague shape of a delta. In this paper he also described the drying up of Lake Ngami and the blocking up of the Taoghe channel which used to feed the lake. However, his map, reproduced on a scale of 1: 4 000 000, was too small to show much of the detail in the earlier map of J.A.A. Schulz* and A. Hammar* (1897).
Passarge was the first person to describe and interpret inselbergs ("island mountains" - steep-sided granite hills standing out on extensive plains) and his views have been widely accepted by geomorphologists. Some of his papers on southern Africa relating to the earth sciences dealt specifically with his travels in the Transvaal (1896), in southern Africa as a whole (1897) and in Ngamiland (1899); the geology of British Bechuanaland (the first description of the geology of that region, now part of the Northern Cape; 1901); the hydrology of the northern Kalahari basin (1901); the inselberg landscapes of tropical Africa (1904, 1905); climatic changes in southern Africa since the middle of the Mesozoic era (1904); the copper ores of German South West Africa (1905); water management problems in the Kalahari (1906); the natural landscapes and palaeoclimatology of Africa (1908); tectonics of the South African coasts (1908); the formation of pans (dry lakes) in German South West Africa and the Kalahari (1910, 1911, 1943); the formation of the Okavango River valley (1919); and the drying up of Africa (1939); Two southern African non-marine molluscs, Achatina passargei and Viviparus passargei, were named after him.
A second book by him dealing with the subcontinent, Suedafrika: eines Landes-, Volks- und Wirtschaftskunde (Leipzig, 1908, 355 pp) was an excellent, thorough study and remained the standard work on the geography of southern Africa for decades. His ethnological observations formed the basis of a monograph, Die Buschmaenner der Kalahari (Berlin, 1907, 144 pp), as well as some fine ethnogeographic papers on the Hereros of the Kaokoveld (1904) and the ethnography of the Kalahari region (1905). In another paper he reviewed the recent discoveries of stone artefacts at the Victoria Falls and reported his own findings (1906).
Meanwhile Passarge had travelled and made observations in Venezuela (1901-1902), and in Algeria and the Sahara (1906-1907). Geography was at this time emerging as a scientific discipline and while finishing Die Kalahari in 1903 he qualified under Professor Ferdinand von Richthofen of the University of Berlin, the leading geographer of the day, to lecture at the tertiary level. After lecturing on geography at the universities of Berlin (1904-1905) and Breslau (1905-1908) he was appointed professor of geography at the Kolonialinstitut (from 1919 the University of Hamburg). He remained in this position for many years, well past his normal retirement age, until the nineteen-fifties. He published extensively during his lifetime, producing seventeen substantial books. These included Beschreibende landschaftkunde (2nd ed., 1929); Die Erde und ihr Wirtschaftsleben (1926); Morphologie der erdoberflaeche (1929); Geographische voelkerkunde (1933); and Die deutsche landschaft (1936). He also authored well over 200 papers and other items. In some of his publications he supported the controversial "landscape science" of the nineteen-twenties, while during the next two decades he published mainly on political and cultural geography. Although many of his colleagues regarded his views as controversial he was nonetheless awarded the Ritter Medal by the highly esteemed Gesellschaft fuer Erdkunde zu Berlin in 1953, and an honorary doctorate by the University of Hamburg in 1956.