Neoproterozoic geodynamic evolution of SW-Gondwana: a southern African perspective

Abstract

Our current understanding of the tectonic history of the principal Pan-African orogenic belts in south-

The Rio de la Plata craton and the adjoining Pan-African/brasiliano terranes: Their origins and incorporation into south-west Gondwana

“…1998;Kroner et al, 2004) and c. 1.2 Ga (Frimmel et al, 2010). Arc-related granites and migmatitic gneisses of 1.73-1.87 Ga have been reported in the pre-Damaran basement of northern Namibia while to the north of the Kaoko belt, there is robust geochronological evidence indicating that Eburnean igneous and metamorphic rocks were affected by a 1320-1340 Ma upper amphibolite fades metamorphism (Seth et al, 2005;Frimmel et al, 2010 and references therein). The detrital zircon age pattern of Neoproterozoic metasedimentary rocks from the Orogen Core of the Kaoko belt exhibits variable proportions of all these components, grouping at 1950, 1230, 1760, 1440, 1005 and 2510 Ma, given in decreasing relative abundance (Goscombe et al, 2005) (Fig.…”

“…In the Gariep belt, the record of alkaline events started with granitic-to-syenitic belts at 833 ± 3 Ma and was followed by intrusion of bostonitic dykes and related volcanic rocks at 801 ± 8 Ma. Rifting continued at 771 ± 6 Ma along a southwest-northeast linear trend, and ended with rift sediment deposition and felsic volcanism at 741 ± 6 Ma (Frimmel et al, 2001 between the two cratons during the Neoproterozoic-Early Palaeozoic interval has been a long debated topic (see Johnson et al, 2005;Gray et al, 2008;Frimmel et al, 2010 as examples of different approaches). However, recent results show that while the timing of rift magmatism was roughly coeval in the Gariep, Damara and Kaoko belts, in the Congo craton this occurred as early as 880-920 Ma, as recorded in the Lufilian, West Congo and Arac;ual belts (Frimmel et al, 2010).…”

“…Rifting continued at 771 ± 6 Ma along a southwest-northeast linear trend, and ended with rift sediment deposition and felsic volcanism at 741 ± 6 Ma (Frimmel et al, 2001 between the two cratons during the Neoproterozoic-Early Palaeozoic interval has been a long debated topic (see Johnson et al, 2005;Gray et al, 2008;Frimmel et al, 2010 as examples of different approaches). However, recent results show that while the timing of rift magmatism was roughly coeval in the Gariep, Damara and Kaoko belts, in the Congo craton this occurred as early as 880-920 Ma, as recorded in the Lufilian, West Congo and Arac;ual belts (Frimmel et al, 2010). There is an increasing amount of evidence indicating that the Angola block, located to the north of the Damara belt, was a separate plate that was not part of the Congo craton (Porada and Berhorst, 2000); Heilbron et al (2008 and references therein).…”

“…The basement slivers include sectors with granitoid gneisses of c. 2.59-2.65 Ga, c. 1.96-2.03 Ga. c. 1.68-1.78 Ga. c. 1.45-1.52 Ga (5eth et al. 1998;Kroner et al, 2004) and c. 1.2 Ga (Frimmel et al, 2010). Arc-related granites and migmatitic gneisses of 1.73-1.87 Ga have been reported in the pre-Damaran basement of northern Namibia while to the north of the Kaoko belt, there is robust geochronological evidence indicating that Eburnean igneous and metamorphic rocks were affected by a 1320-1340 Ma upper amphibolite fades metamorphism (Seth et al, 2005;Frimmel et al, 2010 and references therein).…”

Non-cylindrical parasitic folding and strain partitioning during the Pan-African Lufilian orogeny in the Chambishi-Nkana Basin, Central African Copperbelt

“…Selected age constraints on tectono-metamorphic events before, during and after deposition of the Katanga Supergroup with interpretation of the major events. Age data are shown with error of 2σ and compiled from Barra et al, (2004), Barra (2005), Muchez et al, (2015) and Eastern Zambian Copperbelt data in Sillitoe et al, (2017) for Re-Os dating; Decrée et al, (2011) for U-Pb dating; Cosi et al, (1992), Hanson et al, (1993), Key et al, (Key et al, 2001), Barron et al, (2003), John et al, (2004), Master et al, (2005); Rainaud et al, 5 (2005b), Armstrong et al, (2005) and Johnson et al, (2005) for various igneous and tectono-metamorphic events and Frimmel et al, (2011) for the timing of the Petit and Grand Conglomérat. The base of the Nguba and Kundulungu Groups are defined by the base of the Grand Conglomérat and the Petit Conglomérat respectively.…”