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Inherited drainage - paleochannels and preferential groundwater flow

Owen, Richard and Dahlin, Torleif LU (2010) In Hydrogeology Journal 18(4). p.893-903
Abstract
It is suggested that in a localized remnant of Kalahari sand at Dufuya, central Zimbabwe, groundwater flows in an integrated pattern inherited from the paleochannel network of the underlying gneiss. Contact springs occur at discrete localities along the Kalahari sand/gneiss boundary and are associated with spring sapping and land surface subsidence. Subsidence is presumed to be due to preferential solute removal by leaching and dissolution as a result of concentration of groundwater flow within the buried paleochannel network and the location of the springs is presumed to occur where the paleochannel network intersects the Kalahari sand/gneiss boundary. Over time the surficial Kalahari sand is preferentially removed along these buried... (More)
It is suggested that in a localized remnant of Kalahari sand at Dufuya, central Zimbabwe, groundwater flows in an integrated pattern inherited from the paleochannel network of the underlying gneiss. Contact springs occur at discrete localities along the Kalahari sand/gneiss boundary and are associated with spring sapping and land surface subsidence. Subsidence is presumed to be due to preferential solute removal by leaching and dissolution as a result of concentration of groundwater flow within the buried paleochannel network and the location of the springs is presumed to occur where the paleochannel network intersects the Kalahari sand/gneiss boundary. Over time the surficial Kalahari sand is preferentially removed along these buried drainage lines by spring sapping and headwards erosion, exposing the gneiss. Multi-electrode direct current resistivity profiling and radar have been used to map the sub-surface, revealing the topography of the basement and nature of the Kalahari cover. Coincidence of gneiss basement depressions with the spring sites, leached sands and subsidence zones suggests inheritance of the gneiss fluvial paleochannel network pattern by the present day groundwater flow. Washed sand and gravel intersected in shallow boreholes in these areas provides further evidentiary support for the concept of inherited drainage. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Geophysical methods, Inherited drainage, Preferential groundwater flow, Kalahari, Zimbabwe
in
Hydrogeology Journal
volume
18
issue
4
pages
893 - 903
publisher
Springer
external identifiers
  • wos:000277943700007
  • scopus:77952797381
ISSN
1431-2174
DOI
10.1007/s10040-010-0588-y
language
English
LU publication?
yes
id
9052263e-5503-45e7-8d24-d08c8dd9b1e6 (old id 1617502)
date added to LUP
2010-06-21 15:42:20
date last changed
2018-05-29 10:40:52
@article{9052263e-5503-45e7-8d24-d08c8dd9b1e6,
  abstract     = {It is suggested that in a localized remnant of Kalahari sand at Dufuya, central Zimbabwe, groundwater flows in an integrated pattern inherited from the paleochannel network of the underlying gneiss. Contact springs occur at discrete localities along the Kalahari sand/gneiss boundary and are associated with spring sapping and land surface subsidence. Subsidence is presumed to be due to preferential solute removal by leaching and dissolution as a result of concentration of groundwater flow within the buried paleochannel network and the location of the springs is presumed to occur where the paleochannel network intersects the Kalahari sand/gneiss boundary. Over time the surficial Kalahari sand is preferentially removed along these buried drainage lines by spring sapping and headwards erosion, exposing the gneiss. Multi-electrode direct current resistivity profiling and radar have been used to map the sub-surface, revealing the topography of the basement and nature of the Kalahari cover. Coincidence of gneiss basement depressions with the spring sites, leached sands and subsidence zones suggests inheritance of the gneiss fluvial paleochannel network pattern by the present day groundwater flow. Washed sand and gravel intersected in shallow boreholes in these areas provides further evidentiary support for the concept of inherited drainage.},
  author       = {Owen, Richard and Dahlin, Torleif},
  issn         = {1431-2174},
  keyword      = {Geophysical methods,Inherited drainage,Preferential groundwater flow,Kalahari,Zimbabwe},
  language     = {eng},
  number       = {4},
  pages        = {893--903},
  publisher    = {Springer},
  series       = {Hydrogeology Journal},
  title        = {Inherited drainage - paleochannels and preferential groundwater flow},
  url          = {http://dx.doi.org/10.1007/s10040-010-0588-y},
  volume       = {18},
  year         = {2010},
}