Die geologie van die Sishen-ysterertsmyn

• Main Author: Van Schalkwyk, John Francois
• Published: 2014
• Subjects: Geology - South Africa - Sishen; Iron ores - South Africa - Sishen
• Online Access: http://hdl.handle.net/10210/9598

M.Sc. (Geology) === The Sishen Iron Ore Mine is situated in the Northern Cape Province at the northern extremity of the Maremane dome. The stratigraphy of the Sishen Iron Ore Mine consist of carbonate rocks of the Campbellrand Subgroup which are unconformably overlain by the Wolhaarkop Breccia. The Wolhaarkop Breccia grades upwards through a shaly unit into an succession of iron formation known as the Manganore Iron Formation. The positive correlation of the Manganore Iron Formation with the Asbesheuwels Subgroup, of which it represents the oxidized equivalent, assigns a collapse origin to the Wolhaarkop Breccia. The siliciclastic Gamagara Formation overlies the Manganore Iron Formation unconformably. The unconformity cuts through the Manganore stratigraphy into the carbonate rocks of the Campbellrand Subgroup. The Gamagara Formation consist of a basal unit of conglomerates and argillite of varying thickness in the form of stacked upward fining alluvial cycles. These are overlain by two well 'developed upward coarsening progradational shale to quartzite deltaic cycles. A massive argillite unit marks the upper contact of the Gamagara Formation with the overlying Makganyene and Ongeluk Formations. This unit represents a milonite along a thrust plane and the Ongeluk lava and parts of the Makganyene diamictite were thrusted over the Gamagara Formation which is a correlative of the Mapedi Formation of the 01ifantshoek Group...