Page 154 - Fundamentals of Geomorphology

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a
Ganga

b
()
Malwa
Narmada Vitoria
R.
Tapti
Paraná São
R. Paulo RiodeJaneiro o
n
e
eJ
od
i
R
a
r
i
Paraguay
Western
Ghats
Bay of
Arabian Bay of
Arabian
Porto Alegre
Bengal
Sea Bengal South Atlantic
Sea
South Atlantic
400 km
400 km
400 km
400 km
c
()
c ()
Bié
Highlands
Kariba
Lake
Zambezi
Cubango
Etendeka
Kalahari
Desert
Limpopo
Pretoria
Pretoria
Drakensberg
Vaal
Oranjemond Orange
Oranjemond
Durban
400 km
400 km Durban
Figure 5.18 Drainage patterns influenced by mantle plumes. (a) The drainage pattern of peninsula, India with the
postulated Deccan plume superimposed. Most of the peninsula preserves dome-flank drainage. The Gulf of Cambay,
Narmada, and Tapti systems exhibit rift-related drainage. (b) The drainage pattern of southern Brazil with superimposed
plume. Dome-flank drainage is dominant except near Porto Alegre. (c) The drainage pattern in south-eastern and
south-western Africa with the Paraná plume (left) and Karoo plume (right) superimposed. Rivers over the Paraná plume
show an irregular dome-flank pattern drainage eastwards into the Kalahari. Notice that the Orange River gorge is formed
where antecedent drainage has cut through younger uplift. Rivers over the Karoo plume display preserved dome-flank
drainage west of the Drakensberg escarpment. The dotted line separates dome-flank drainage in the south from
rift-related drainage in the north.
Source: Adapted from Cox (1989)