Provenance study from petrography of the late Permian – Early Triassic sandstones of the Balfour Formation Karoo Supergroup, South Africa

• Petrographic analysis of the clastic sediment of the Balfour Formation, Karoo Basin.
• The Cape Fold Belt is the primarily provenance of the Balfour Formation.
• Classification of Balfour sandstones as feldspathic litharenite and ultralithofeldspathic.

Non marine clastic sediments from the Late Permian – Early Triassic Balfour Formation of the Karoo Supergroup were studied to infer the composition, provenance and influence of weathering conditions. Petrographic studies based on quantitative analysis of the detrital minerals reveal that these sediments (mainly sandstones) are mostly composed of quartz, feldspar and sedimentary and metamorphic rock fragments. There is no significant petrographic variation across the sandstone succession of the study. The sandstones are dominantly feldspathic litharenite and ultralithofeldspathic in composition indicating a metamorphic source area. Modal analysis data plot in the dissected and transitional arc block provenance fields of QmFLt (quartz-feldspar-lithic fragments) diagram suggesting an active margin and magmatic arc signature preserving a recycled provenance.