Editing Zambezi (section)

== Geological history ==
[[File:Victoria Falls National Park marker.jpg|thumb|Victoria Falls National Park marker]]
Up to the [[Piacenzian|Late Pliocene]] or [[Pleistocene]] (more than two million years ago), the upper Zambezi flowed south through what is now the [[Makgadikgadi Pan]] to the [[Limpopo River]].<ref>{{cite journal |last1=Goudie |first1=A.S. |author-link=Andrew Goudie (geographer) |date=2005 |title=The drainage of Africa since the Cretaceous |journal=[[Geomorphology (journal)|Geomorphology]] |volume=67 |issue=3–4 |pages=437–456 |doi=10.1016/j.geomorph.2004.11.008 |bibcode=2005Geomo..67..437G}}</ref> The change of the river course is the result of [[epeirogenic movement]]s that lifted up the surface at the present-day water divide between both rivers.<ref>{{cite journal |last1=Moore |first1=A.E. |date=1999 |title=A reapprisal of epeirogenic flexure axes in southern Africa |journal=[[South African Journal of Geology]] |volume=102 |issue=4 |pages=363–376}}</ref>

Meanwhile, {{cvt|1000|km|mi}} east, a western tributary of the Shire River in the [[East African Rift]]'s southern extension through [[Malawi]] eroded a deep valley on its western escarpment. At a slow rate, the middle Zambezi started cutting back the bed of its river towards the west, aided by [[graben]]s ([[rift valley]]s) forming along its course in an east–west axis. As it did so, it [[Stream capture|captured]] several south-flowing rivers such as the Luangwa and Kafue.

Eventually, the large lake trapped at Makgadikgadi (or a tributary of it) was captured by the middle Zambezi cutting back towards it, and emptied eastwards. The upper Zambezi was captured, as well. The middle Zambezi was about {{cvt|300|m|ft}} lower than the upper Zambezi, and a high waterfall formed at the edge of the basalt plateau across which the upper river flows. This was the first Victoria Falls, somewhere down the Batoka Gorge near where Lake Kariba is now.<ref>[http://www.zamsoc.org/documents/Summary%20of%20Technical%20Reviews%20Part%202.pdf AWF Four Corners Biodiversity Information Package No 2: Summary of Technical Reviews] {{webarchive |url=https://web.archive.org/web/20120217063008/http://www.zamsoc.org/documents/Summary%20of%20Technical%20Reviews%20Part%202.pdf |date=17 February 2012 }} Accessed 1 March 2007.</ref>