Colin Hayter Crickmay (1899–1988) was Canadian

geomorphologist Geomorphology (from Ancient Greek: , ', "earth"; , ', "form"; and , ', "study") is the scientific study of the origin and evolution of topography, topographic and bathymetry, bathymetric features created by physical, chemical or biological pro ...

known for his contributions to

river A river is a natural flowing watercourse, usually freshwater Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. Although the ...

and hillslope

erosion Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited. Erosion is di ...

. Influenced by the observations of the

geologist A geologist is a scientist who studies the solid, liquid, and gaseous matter that constitutes Earth and other terrestrial planets, as well as the processes that shape them. Geologists usually study geology, earth science, or geophysics, alt ...

Eleanora Knopf he coined the concept of unequal activity to describe the great disparities that can between stream erosion near stream channels and apparently unchanged uplands, and between headwaters with limited erosion and the more active middle and lower courses of streams. Crick did also coin the term panplanation to describe a

planation surface In geology and geomorphology a planation surface is a large-scale surface that is almost flat with the possible exception of some residual hills. The processes that form planation surfaces are labelled collectively planation and are exogenic (chi ...

s thought to be formed by lateral stream migration.

References

1899 births 1988 deaths Canadian geographers 20th-century Canadian geologists Geomorphologists 20th-century geographers {{Geologist-stub