The Geographic
Cycle
WM Davis
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
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.
Information provided by: http://www.minerals.nsw.gov.au
James Hutton by Abner Lowe
Landscape is a Function of these
Geographical Controls
• Structure
–Horizontal (plains, etc.)
–Disordered (mountains, etc.)
• Process
• Time
The Landscape
W. M. Davis
Davisian Analysis
Rejuvenation
“Youth”
uplift
base level fall
relief increase;
“Maturity”
then, decrease
“Old Age”
In the 1960s and 1970s, Henry Besairie mapped much of the central plateau
of Madagascar as dissected peneplain…discuss! (Google Earth)
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.
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)
“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;….
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?
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. “