The Geographic Cycle

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The Geographic Cycle

• WM Davis

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William Morris Davis

• Born February 12, 1850, Philadelphia, PA
• -Graduated from Harvard 1869
• -Instructor of geology at Harvard, 1879
• (never finished his Ph.D.)
• -In addition to work on physical geography,
• Davis was very involved in educational
• theory and professional association (founded
• the Association of American Geographers, 1904)
• -Died February 5, 1934, Pasadena, CA
• Source http//www.wikipedia.org

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Historical Context

• Development of geology as a separate branch of
  science -1775 to 1830.
• Hutton (1726-1797) -uniformitarinism. John
  Playfair (1748-1819) publicised Hutton's theories
  and added further ideas.
• Lyell published the classic textbook, 'Principles
  of Geology', in 1830-1833.
• William Smith (1769-1839)-stratigraphical
  successions based on fossils
• By the middle of the Nineteenth Century, the
  general geological time scale based on fossils
  and stratigraphic mapping was established.
• Geomorphological studies were advanced by the
  work of Agassiz, who in the 1840s recognised the
  effects of Pleistocene glaciation in Europe and
  the USA.
• Later Gilbert and Powell made classical studies
  on arid erosion in the western USA.
• The strongest influence up to 1900 was the work
  of W.H. Davis, an American who worked both in USA
  and Europe and who first defined the cycle of
  erosion.

James Hutton by Abner Lowe
Information provided by http//www.minerals.nsw.g
ov.au
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Landscape is a Function of these Geographical
Controls

• Structure
• Horizontal (plains, etc.)
• Disordered (mountains, etc.)
• Process
• Time

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In the 1960s and 1970s, Henry Besairie mapped
much of the central plateau of Madagascar as
dissected peneplaindiscuss! (Google Earth)
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Facts of Observation (pg. 484)

• The explorer of the Earth should be as fully
  convinced of this principle (that geolographical
  landforms have meaning), and as well prepared to
  apply it, as the explorer of the sky is to carry
  physical principles to the furthest reach of his
  telescope, his spectro- scope, and his camera.
  The preparation of route-maps is only the
  beginning of exploration, which has no end till
  all the facts of observation are carried forward
  to explanation.

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Challenges Geographers to become
Wasteformologists

• As a consequence, the scheme gains a very "
  theoretical" flavour that is not relished by some
  geographers, whose work implies that geography,
  unlike all other sciences, should be developed by
  the use of only certain ones of the mental
  faculties, chiefly observation, description, and
  generalization. (483)

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Systematic Investigation of Land-forms(pg. 498)

• Its value to the geographer is not simply in
  giving explanation to land- forms its greater
  value is in enabling him to see what he looks at,
  and to say what he sees.
• Significant features are consciously sought for
  exploration becomes more systematic and less
  haphazard.."A hilly region" brings no definite
  picture before the mental eyes. "A maturely
  dissected upland" suggests a systematic
  association of well-defined features.

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Discussion Points

• So with waste-sheets they normally begin to
  establish a graded condition at their base, and
  then extend it up the slope of the valley side
  whose waste they drain. (pg. 496)
• Rills on hillslopes also graded in old age? (489)
• Stream terminology consequent, insequent,
  etc. (pg 490-493)
• Figure 1?

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Romans?

• To look upon a landscape of this kind without
  any recognition of the labour expended in
  producing it, or of the extraordinary adjustments
  of streams to structures, and of waste to
  weather, is like visiting Rome in the ignorant
  belief that the Romans of to-day have had no
  ancestors.

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