Katanga formation

Song Xiaojun et al. (2009) divided the lithology of the Katanga Supergroup strata in Katanga Province in detail through geological exploration in Congo (DRC), and summarized some regular understandings:

1), the bottom of Luoen Formation (Rl) is feldspathic sandstone and gravel layer, and the gravel has good roundness. After leveling and structural erosion, the underlying Kibala supergroup metamorphic rock series appears poorly sorted feldspathic sandstone and breccia (round gravel) which represents the deposition after structural erosion. In addition to argillaceous and sandy components, this layer also contains multicycle stromatolite dolomite, which is rich in Proterozoic in the world. Recently, the wet process company affiliated to China Nonferrous Mining Group exposed typical spherical stromatolites in the open pit of Shamitumba copper-cobalt mine in Katanga Province, Democratic Republic of Congo (Figure 4-1); Stromatolite dolomite is in close contact with ore-bearing sandy slate, which is basically the same as that in Zambia Copper Belt Province.

Figure 4- Stromatolite Dolomite 1

2) Graphite, stromatolite and talc appear in the middle and upper part of the middle Ron subgroup (R2), and the content of dolomite in the main rocks increases, which is the product of typical coastal and shallow sea environment deposition. These rocks are rich in magnesium, located in deep water and rich in stromatolites. Graphite and talc may be the result of dynamic metamorphism of carbon-rich and magnesium-rich rocks in the later period.

3) The higher Ron subgroups (R3 and R4) include dipet(R3) and Muvasha (R4). Except the sandy schist at the bottom, the middle and upper parts are all dolomite, in which oolite, jasper, hematite and flint nodules are developed, indicating that the hydrodynamic conditions of the sedimentary environment are relatively strong and the water depth is relatively oxidized.

4) The bottom of Lower Kong Delong Paleosubgroup (Kl) is moraine, which is unconformity contact with Muwasha Group, and there is obvious sedimentary discontinuity. Due to the late regional nappe and overthrust, in some places, moraine can be seen in direct contact with the metamorphic basement of Kibala Supergroup.

5) There are moraines between the Upper Kong Delong Paleosubgroup (K2) and the Lower Kong Delong Paleosubgroup, which are the products of global glacial events at the end of Neoproterozoic, and the time limit is roughly equivalent to the Nantuo Glaciation in the south of China and the Luo Huan Glaciation in the north. This geological event is very obvious and important in Katanga province, and it is also a very striking landmark.