The Mwembeshi Shear Zone is a ductile shear zone about 550 million years old that extends ENE-WSW across

Zambia Zambia (), officially the Republic of Zambia, is a landlocked country at the crossroads of Central, Southern and East Africa, although it is typically referred to as being in Southern Africa at its most central point. Its neighbours are t ...

. In Zambia, it separates the Lufilian Belt to the northwest from the

Zambezi Belt The Zambezi Belt is an area of orogenic deformation in southern Zambia and northern Zimbabwe. It is a segment of a broader belt lying between the Congo Craton and the Kalahari Craton, which also includes the Lufilian Arc and the Damaran Belt. The ...

to the southeast. It is associated with a

sinistral Sinistral and dextral, in some scientific fields, are the two types of chirality ("handedness") or relative direction. The terms are derived from the Latin words for "left" (''sinister'') and "right" (''dexter''). Other disciplines use different ...

strike slip movement. The Mwembeshi Shear Zone lies between the

Congo craton The Congo Craton, covered by the Palaeozoic-to-recent Congo Basin, is an ancient Precambrian craton that with four others (the Kaapvaal, Zimbabwe, Tanzania, and West African cratons) makes up the modern continent of Africa. These cratons were fo ...

to the NW and the

Kalahari craton The Kalahari Craton is a craton, an old and stable part of the continental lithosphere, that occupies large portions of South Africa, Botswana, Namibia and Zimbabwe. It consists of two cratons separated by the Limpopo Belt: the larger Kaapvaal Cra ...

to the SE, to the west (in today's orientation) of the

Mozambique Belt The Mozambique Belt is a band in the earth's crust that extends from East Antarctica through East Africa up to the Arabian-Nubian Shield. It formed as a suture between plates during the Pan-African orogeny, when Gondwana was formed. The Mozambiq ...

, which is on the north and east side of the Kalahari Craton. It was formed during the

Pan-African orogeny The Pan-African orogeny was a series of major Neoproterozoic orogenic events which related to the formation of the supercontinents Gondwana and Pannotia about 600 million years ago. This orogeny is also known as the Pan-Gondwanan or Saldanian Oro ...

when "North" and "South" Gondwana were amalgamated along the

Kuunga orogeny The Kuunga orogeny (from Swahili, "to unite") was an orogeny that occurred in South-east Africa during the Ediacaran and Cambrian. Composed of three separate orogenic belts (Damara, Zambesi, and Lurio) that are slightly younger than the East Afr ...

zone between 580 Ma and 480 Ma. The date of around 550 Ma for the Mwembeshi shear zone is based on U-Pb zircon ages of syntectonic granites from the Hook massif and of associated

hypabyssal A subvolcanic rock, also known as a hypabyssal rock, is an intrusive igneous rock that is emplaced at depths less than within the crust, and has intermediate grain size and often porphyritic texture between that of volcanic rocks and plutonic r ...

rhyolite. During the amalgamation there was sinistral

transpression In geology, transpression is a type of strike-slip deformation that deviates from simple shear because of a simultaneous component of shortening perpendicular to the fault plane. This movement ends up resulting in oblique shear. It is generally v ...

along the boundary between the Kalahari craton and the Congo and

Tanzanian Tanzania (; ), officially the United Republic of Tanzania ( sw, Jamhuri ya Muungano wa Tanzania), is a country in East Africa within the African Great Lakes region. It borders Uganda to the north; Kenya to the northeast; Comoro Islands and ...

cratons (which had already amalgamated), which is now expressed as the Mwembeshi Shear Zone. The sinistral sense shows that, in modern coordinates, the Congo-Sao Francisco Craton approached the remainder of southwestern Gondwana from the north, although at the time southwestern Gondwana was oriented about 90 degrees clockwise of today's orientation, and the Congo Craton approached from the east. There was little vertical displacement, but Mwembeshi is a major sinistral transcurrent shear zone. The shear zone accommodates a change in the structural vergence between the Zambezi Belt and the Lufilian Arc. Further to the southwest, the shear zone extends along part at least of the Damaran belt. There are known to be basic connections between geological terranes and mineralization models, so understanding the Mwembeshi Shear Zone is important to understanding where mineral resources may be found in the region. Despite this, as of 1990 there had been relatively little exploration.

References

;Citations ;Sources * * * * * Geology of Africa Seismic faults of Africa Shear zones {{palaeo-geo-stub