Lower Permian deposits of the Huab area, NW Namibia: a continental to marine transition
Understanding the facies development of the Huab area is important as this area provides a bridge between the Permian deposits of South Africa and southern Namibia and those of the Paraná Basin in Brazil. Post-glacial Permian environments in the Huab area were initiated by widespread, meandering river systems recorded by sandy point bar and coal-bearing floodplain deposits of the Verbrandeberg Formation. The base of the Tsarabis Formation is dominated by laterally amalgamated braided channel sandstones. These fluvial units interfinger upwards with wave-dominated deltaic and shoreface deposits bearing a variety of marine trace fossils. The overlying Huab Formation contains large-scale stromatolite ridges with flat pebble conglomerates formed in tidal channels between the ridges. The entire succession was later buried by landward-onlapping marine mud- and marlstones recording the peak of an overall transgressive development. Facies architecture varies considerably in cross-section perpendicular to the present-day continental margin, which is interpreted to reflect syn-depositional normal faulting during early South Atlantic rifting. This requires detailed palaeo-environmental analyses because it is assumed that marine-influenced Karoo-aged rocks in Namibia and Brazil trace the axis of a broad southern South Atlantic intracontinental rift zone.
Communications of the Geological Survey of Namibia
Attachment | Size |
---|---|
Lower Permian deposits of the Huab area_NW Namibia a continental to marine transition.pdf | 2.04 MB |