Kogin Dwyka
Kogin Dwyka yana cikin yankin Karoo, a Afirka ta Kudu .Yana kwararowa daga Arewa-maso-Yamma, yana shiga kogin Gamka a matsayin rafi a madatsar ruwan Gamka .

A cikin 1870s, gwamnatin Cape Colony ta faɗaɗa hanyar sadarwar jirgin ƙasa a cikin ƙasa,zuwa filayen lu'u-lu'u na Kimberley.An gina tasha mai suna Dwyka inda layin ya ratsa kogin Dwyka.

Bayan haka kuma masana ilimin kasa sun karvi sunan kogin don ayyana zamanin Karoo kankara kimanin shekaru miliyan 300 da suka wuce. Muhimman wurare a Afirka ta Kudu suna nuna shaidar glaciation,gami da Nooitgedacht kusa da Kimberley.A Afirka ta Kudu,kusa da Pole ta Kudu a wancan lokacin sakamakon farantin tectonics,manyan kankara ko glaciers sun rufe wuraren da ke kwance. Masana ilimin kasa sun ce wannan tuddai mai tuddai na Cargonia,wanda ya tashi daga yankin arewacin Cape ta Gauteng zuwa Mpumalanga.

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