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Atlas

Domboshawa

The Chinamora Igneous Complex, some 1 500 sq km in extent, is an area of granitoid rocks north of Harare which is almost completely enveloped by ancient volcanic and metasedimentary rocks of the Harare-Shamva Greenstone Belt.  The clear distinction between these two terrains, as one drives north towards Domboshawa, is a change from heavy red-brown loams to pale yellow-grey sandy soils.  The plutonic complex is roughly elliptical in shape and it comprises a variety of gneisses, migmatites and granites of different age and composition.

Kaburi anticlinal fold structure

Makuti Group quartzo-feldspathic gneiss.
 
The Kaburi anticlinal fold structure with axis parallel to the NW regional trend, which can be traced over many tens of kilometres.  The strongly deformed alternating lithologies comprising feldspathic gneiss, biotite gneiss, pelitic schist, quartzite, calc silicate rock and amphibolite are sometimes thrown into refolded interference patterns.
 
Stop 5 on the attached field guide

Malaputese Group at Gwayi River Mine (dumps around the Adder adit).

The Gwayi River Mine (formerly Gwaai River Mine) was operated by Messina (Transvaal) Development Corporation from 1970 until 1975, when the mine was closed for economic reasons. The mines have been dormant ever since, but since 2010, a Chinese company, Sino-Mining, has been doing exploration in the area.

Charleswood Diamonds

Following discovery of alluvial gold at Tarka Forest in 2004 and subsequent acquisition of a Special Grant over the area by the Zimbabwe Mining Development Corporation, a lot of interest was roused on the gold potential of the Chimanimani area. This resulted in DTZ-Ozgeo, a company specialised in alluvial minerals, securing a Special Grant (SG 4955) in 2007 to explore for gold in an area encompassing Charleswood Farm adjacent to Tarka Forest, about 15 km east of Chimanimani.

Kariba biotite gneiss overlain by basal red mudstone of the Lower Karoo Group

Kariba biotite gneiss at the Nyanyana bridge foundation overlain by basal red mudstone of the Lower Karoo Group. 
 
The Nyanyana River bridge, crossed just prior to passing the turnoff to Kariba Airport, is founded on strongly foliated and folded biotite gneiss.  The basal unit to the Karoo Supergroup, as in adjacent parts of Zambia, is a red mudstone with basal conglomerate in places.

Marange Diamonds

De Beers discovered the Marange fossil placer diamond deposit in 2003 during the tenure of their exploration licence (EPO 1523) covering the Marange area. The exploration was targeted at discovering kimberlitic diamonds, but the recovery of rounded diamonds in some heavy mineral samples collected from local streams led to suspicions of a secondary source for the diamonds. A search for the possible source led to the discovery of a mineralized conglomerate. 
 
The discovery attracted informal miners from all over the country and abroad.

Kariba porphyritic biotite granitoid gneiss

The Kariba porphyritic biotite granitoid gneiss is coarse-grained, with a weak gneissic fabric, and contains large K-feldspar phenocrysts, and numerous decimetric slab-like mafic xenoliths. It contains small garnets rimmed and replaced by biotite. The zircons dated have oscillatory zoning in the centre (of igneous origin), but the margins have been affected by metasomatic alteration zones, and in some cases have discrete overgrowth rims. The zircons have yielded ages of 1962.9 ± 8.5 Ma and 2.1-2.17 Ga.

Palaeoproterozoic (ca 2.07 Ga) granitoid , with complex (inherited) 3.4 and 2.7 Ga zircons

In this outcrop, there is a deformed granite with anastomosing subhorizontal fractures, which is weathered with brownish iron oxide staining. It has yielded a very complex set of zircons, with inherited cores as old as 3.4 Ga, with 2.7 Ga overgrowths, and a final overgrowth at 2.07 Ga, which is possibly the age of intrusion of the granite, which was subsequently deformed (Master et al., 2013a,b).

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