Geology Reference
In-Depth Information
On the windward side of the orogen, higher runoff
generated by higher precipitation totals leads to higher
rates of denudation than on the drier, leeward side. As a
result, crustal rocks rise more rapidly on the windward
flank than on the leeward flank, so creating a patent
asymmetry in depths of denudation across the orogen
and producing a characteristic pattern of crustal defor-
mation. Such modelling studies indicate that a reversal
of prevailing rain-bearing winds will produce a change in
topography, spatial patterns of denudation, and the form
of crustal deformation (Summerfield 2007). In addi-
tion, they show that the topographic and deformational
evolution of orogens results from a complex interplay
between tectonic processes and geomorphic processes
driven by climate.
influence upon such continental-scale landforms as
mountain belts, but there is an important interplay
between uplift, climate, and denudation.
ESSAY QUESTIONS
1 Explain the landforms associated
with active margins.
2 Explain the landforms associated
with passive margins.
3 Examine the factors that determine
the major relief features of the Earth's
surface.
SUMMARY
FURTHER READING
Geological processes and geological structures stamp
their marks on, or in many cases under, landforms
of all sizes. Plate tectonic processes dictate the gross
landforms of the Earth - continents, oceans, mountain
ranges, large plateaux, and so on - and many smaller
landforms. Diastrophic forces fold, fault, lift up, and
cast down rocks. Orogeny is a diastrophic process that
builds mountains. Epeirogeny is a diastrophic process
that upheaves or depresses large areas of continental cores
without causing much folding or faulting. The bound-
aries of tectonic plates are crucial to understanding many
large-scale landforms: divergent boundaries, convergent
boundaries, and transform boundaries are associated with
characteristic topographic features. Incipient divergent
boundaries may produce rift valleys. Mature diver-
gent boundaries on continents are associated with passive
margins and great escarpments. Convergent boundaries
produce volcanic arcs, oceanic trenches, and mountain
belts (orogens). Transform boundaries produce fracture
zones with accompanying strike-slip faults and other
features. Plate tectonic processes exert an important
Burbank, D. W. and Anderson, R. S. (2001)
Tectonic
Geomorphology: A Frontier in Earth Science
. Malden,
Mass.: Blackwell Science.
A detailed and insightful discussion of one of geomor-
phology's latest developments, but not easy for trainee
geomorphologists.
Godard, A., Lagasquie, J.-J., and Lageat, Y. (2001)
Base-
ment Regions
. Translated by Yanni Gunnell. Heidelberg:
Springer.
An insight into modern French geomorphology.
Huggett, R. J. (1997)
Environmental Change: The Evolv-
ing Ecosphere
. London: Routledge.
You may find some of the material in here of use. I did!
Summerfield,
M.
A.
(ed.)
(2000)
Geomorphology
and Global Tectonics
, pp.
321-38.
Chichester: John
Wiley & Sons.
Not easy for the beginner, but a dip into this volume
will reward the student with an enticing peep at one of
geomorphology's fast-growing fields.
