Dwala/Ruware. Image credit WordPress.com

Dwala/Ruware. Image credit WordPress.com

ZIMSEC O Level Geography Notes: Landforms resulting from weathering: Dwala

  • Known as ruware in Shona, dwala in Ndebele (Nguni languages) and whaleback in English.
  • An example is Domboshava where several such landforms can be found.
  • It is a hill or rock which is dome shaped and rises several metres from the ground.
  • It is a near level rock outcrop,  that develops where the basal surface is undulating.
  • Dwalas are gently sloping,low lying and rounded or elongated hills.
  • They are about 2-5m in height.
  • They have a gentle, convex summit that is usually smooth but can have sheet joints as a result of pressure release and regolith that is onion-peel shaped as a result of exfoliation.
  • Its slopes are convex/rectilinear and gentle.
  • Might also have vertical joints which begin as fractures as a result of pressure release but are further widened weathering processes.
  • They are surrounded by deeply weathered regolith
  • They are usually bare of vegetation but can be lightly populated by shrubs and bushes.

The formation of dwalas

The diagrams below detail the possible formation of a dwala.

An underground intrusion e.g. batholith is exposed by denudation.

An underground intrusion e.g. batholith is exposed by denudation.

The overburden is removed by denudation processes resulting in pressure release and the formation of a dwala/ruware.

A dwala/ruware is formed when the overbuden is removed.

A dwala/ruware is formed when the overbuden is removed.

To access more topics go to the Geography Notes page.