Transvaal Supergroup

1.Basal volcanic and clastic unit

a.Basaltic lavas and stromatolites interbedded

b.above layer sandwitched between 2 conglomerate progressions

-braided fluvial to deltatic progression

2.Chemical Sediments Unit ( Black Reef or Chuniespoort Approx. 2.5 Ga)

a.Same as Hammersly Basin, Australia

b.Basal Quartzite, carbonates, cherts, banded iron formations

c.Deposition was in restricted saline basins on a techtonically stable margin

3.Upper Clastic Unit

a.Sea retreated=Land exposed to chemical and physical erosion

b.Sea returned and reworked the chemically resistant chert and iron formations creating coarse clastics.