The Hook granite massif is a large formation in central Zambia formed around 550 million years ago during the Pan-African orogeny. It lies in the inner part of the Lufilian arc. Today, the south-western extension of the massif lies under the Kafue National Park.
Field studies and U-Pb (uranium-lead) dating show that the massif is a large composite batholith that has intruded into the upper Katangan (Kundelungu) strata of sediments in the Lufilian arc during or after tectonic activity. Sample U-Pb dates for syntectonic granite in the massif are 559ñ18 and 566ñ5 Ma, and for post-tectonic granite 533ñ3 Ma. These show that the Kundelungu sediments date to before 570 Ma; the deformation of the inner Lufilian arc and voluminous syntectonic granite plutonism took place around 560âÂÂ570 Ma; and the major tectonic activity had ended by around 530âÂÂ540 Ma.
The Hook massif is bounded to the south by the Mwembeshi dislocation, a Pan-African transcurrent shear zone. Syntectonic rhyolite intruded in this shear zone dates to 551ñ19 Ma, so the transcurrent shearing happened about the same time as the batholith intrusion and was probably due to the same causes. Syntectonic and post-tectonic granite plutonism also took place around the same time in the Damara belt in Namibia, indicating a link with the Lufilian arc and Zambezi belt during the Pan-African orogeny.