▁Tri ple ▁j unction , ▁as ▁a ▁part ▁of ▁the ▁Kar oo ▁Lar ge ▁Ig ne ous ▁Province . ▁In tr usion ▁of ▁Ok av ango ▁Dy ke ▁Sw arm ▁occurred ▁in ▁two ▁distinct ▁stages . ▁Most ▁of ▁the ▁dy kes ▁in ▁the ▁sw arm ▁are ▁Kar oo - age , ▁and ▁about ▁ 1 3 % ▁are ▁Pro ter oz o ic ▁age . ▁The ▁age ▁range ▁of ▁Pro ter oz o ic ▁components ▁is ▁ 8 0 0 – 1 6 0 0   Ma , ▁while ▁the ▁dominant ▁Kar oo - age ▁rocks ▁are ▁dated ▁to ▁ 1 7 8 – 1 7 9   Ma . ▁ ▁The ▁mean ▁dy ke ▁thick ness ▁is ▁. ▁ ▁Ge ology ▁of ▁the ▁country ▁rock ▁in ▁N ortheast ▁B ots w ana ▁The ▁dy ke ▁sw arm ▁cut s ▁through ▁Ar che an ▁bas ement ▁rock ▁to ▁the ▁west ▁in ▁Sh as he ▁area , ▁and ▁Jur ass ic ▁vol can ic ▁rocks ▁and ▁sed iment ary ▁sequences ▁to ▁the ▁east ▁in ▁the ▁T uli ▁Gra ben . ▁The ▁bas ement ▁country ▁rocks ▁are ▁Ar che an ▁cry st all ine ▁g ne isses ▁and ▁gran ito ids ▁of ▁the ▁L imp opo ▁B elt . ▁They ▁were ▁found ▁to ▁be ▁de formed ▁in ▁the ▁Pale opro ter oz o ic ▁period . ▁The ▁rock ' s ▁fab rics ▁show ▁fol ding ▁of ▁a ▁number ▁of ▁separate ▁stages . ▁They ▁contain ▁complex ▁tr ending ▁of ▁she ar ▁zones ▁and ▁f ract ure