U-Pb zircon evidence for an extensive early Archean craton in Zimbabwe: A reassessment of the timing of craton formation, stabilization, and growth

Juvenile crust formation in the Zimbabwe Craton deduced from the O-Hf isotopic record of 3.8–3.1 Ga detrital zircons

“…Horstwood et al 1999). Gneisses from the Tokwe segment have Sm-Nd T DM ages between 3.65 and 3.51 Ga (Horstwood et al, 1999;Taylor et al, 1991) and low initial Sr ratios (0.700-0.701; Hawkesworth et al, 1975;Moorbath et al, 1977), suggesting that they were derived from depleted or chondritic mantle sources.…”

“…TTG-type granitoids of the Chingezi Suite (Wilson et al, 1995) are associated with the Lower Greenstones, and occur as intrusions within the Tokwe Segment to the west. These intrusions range in age from 2.98 Ga to 2.75 Ga (Nägler et al, 1997;Taylor et al, 1991;Horstwood 1999). They have been interpreted as the plutonic equivalents of the Belingwean and Lower Bulawayan felsic volcanic rocks (Luais and Hawkesworth, 1994).…”

“…These intrusions were regarded as post-kinematic with respect to the formation of the regional north-oriented fabric and intrusive into Sebakwian Group greenstones, thus providing a minimum age for the Sebakwian Group (Wilson, 1968 1). These rocks have been assigned to the Lower Greenstones (Wilson, 1979), and include rocks of the 2.90-2.88 Ga Belingwean Group and rocks of the 2.83-2.79 Ga Lower Bulawayan Group (Horstwood et al, 1999;Wilson et al, 1995;Prendergast and Wingate, 2013). TTG-type granitoids of the Chingezi Suite (Wilson et al, 1995) are associated with the Lower Greenstones, and occur as intrusions within the Tokwe Segment to the west.…”

“…The oldest part of the Zimbabwe Craton is the pre-3.35 Ga Sebakwe proto-craton of Horstwood et al (1999), which includes high-grade gneiss terrains of the Tokwe segment east of the Belingwe-Shurugwi greenstone belts (e.g. Wilson et al, 1995) and the Rhodesdale granitoid-gneiss terrain east of the Midlands greenstone belt (Robertson, 1976) (Fig.1).…”

“…(iii) to undertake a search for the most ancient zircons preserved to better delineate the extent of the oldest parts of the craton ("Tokwe segment": Wilson et al, 1995;Horstwood et al, 1999);…”