Bushveld igneous complex of the transvaal gsa bulletin. Bushveld igneous complex archives state of the planet. The main mineralized zones in the bic that are of economic importance are the ug2 and. These are the bushveld complex in south africa, the stillwater complex in the u. The bushveld complex, a product of interaction among magmas. Their proposition is largely based on the lithological and compositional similarity. On the relationship between the bushveld complex and its. Regional isotopic variation in the ucz of the bushveld complex. Magmatic ore deposits in layered intrusionsdescriptive model. This article describes the geological and economic aspects of this unusually interesting formation. A vast composite body of plutonic and volcanic rocks in the central part of the transvaal, the bushveld igneous complex includes the platinum reef worked by rustenburg platinum mines limited and constituting the worlds greatest reserve of the platinum metals. Drilling through the largest magma chamber on earth.
The position of the uitkomst complex relative to the bushveld complex is indicated by the cross adapted after. The complex consists essentially of five adjoining, basinshaped masses of igneousrocks. Find out information about bushveld igneous complex. Bushveld igneous com plex geologic map and mine location s the bushveld igneous complex bic is the larg est layered igneous intrusion 1 2 within the earths crust. The geology of the bushveld igneous complex, the largest. Table 1 general estimates for the areal distribution and volume of the various components of the bushveld lip. The complex contains the worlds largest reserves of the platinum group metals, platinum, palladium, osmium, indium, rhodium and rhenium, along with vast quantities of iron, tin, chromium, titanium and vanadium wikipedia. The bushveld igneous complex bic is a large layered igneous intrusion within the earths crust, exposed at the edge of the transvaal basin in south africa. South africa is the worlds top producer of platinum, used in everything from jewelry to catalytic converters.
This is the preface to a special issue on various aspects of the bushveld complex, transvaal basin, south africa. The complex consists of multiple suites of rocks, each of which in turn holds multiple layers. Molengraaff, henderson, kynaston, mellor, humphrey, hall, wagner, and du toit have published the results of study. Felsic end to bushveld differentiation journal of petrology. It has been tilted and eroded forming the outcrops around what appears to be the edge of a great geological basin. It should be noted that the damwal and dullstroom formations are present only in the eastern bushveld. These layered intrusions consist of rocks which cooled slowly from molten magma, deep within the earth. Platinumgroup elements in the upper zone of the rustenburg. Introduction the rustenburg layered suite rls form laterally continues layers that can be correlated across the various limbs of the bushveld igneous complex. As most of the region tends to be dry, the bushveld is mostly beef cattle and game farming country, with only a few droughtresistant crops such as sorghum and millet being farmed, usually under irrigation.
The location of the bushveld igneous complex, south africa. The bushveld complex underlies an area of about 50,000 square km 20,000 square miles. The bushveld complex is part of the massive bushveld igneous province that also includes voluminous ferroan granites and other felsic rocks, all of similar age of. Reeftype and contacttype deposits, in particular those in the bushveld complex, south africa, are the worlds primary source of platinum and rhodium tables 2 and 3. Reos isotope and pdru variations in chromitites from the. Reeftype pge deposits are mined only in the bushveld complex merensky reef and ug2, the stillwater complex jm reef, and the great dyke main sulphide layer. A large igneous province lip is an extremely large accumulation of igneous rocks, including intrusive sills, dikes and extrusive lava flows, tephra deposits, arising when magma travels through the crust towards the surface.
The northern limb is known for the platreef, atypical mafic lithologies in sections of the. Media in category bushveld igneous complex the following files are in this category, out of total. It lies almost entirely within the bounds of the transvaal. The geology is described briefly assuming familiarity on the part of the reader.
Not the least of the finds is the amazing body of igneous rocks called the bushveld complex, in the transvaal. Bushveld is an example of a large igneous province, a massive assemblage of rocks formed by volcanic activity. The bushveld complex the bushveld complex is the worlds largest layered intrusion, and because of its unique char acter most other layered intrusions are compared with it. The authors declare that all relevant data are available within the article and its supplementary information files. Box 106, crown mines, 2025, south africa chromite and pgeenriched layers in the bushveld are modelled on a process of the cooling of resident lower zone magma by sub. The complex includes the merensky reef, which is the worlds biggest source of platinum as well as platinumgroup metals. Bushveld igneous complex article about bushveld igneous. It is a large complex covering a major area of the province formerly known as the transvaal which has since been divided up and the bushveld igneous complex now occurs in the following provinces. Hence, the vertical inflation of the bushveld complex, or parts thereof, may have been accommodated by floor depression in response to volume loss, thus producing a lopolith e. Bushveld igneous complex and the overlying rooiberg group felsic volcanic rockssuggestthe possibilitythatthetwo are cogenetic. Layered igneous intrusions and most famous is the bushveld complex in south africa, which is 9 km 5. If the file has been modified from its original state, some details such as the timestamp may not fully reflect those of the original file.
Bushveld minerals is a lowcost, vertically integrated primary vanadium producer with a diversi. This highly informative book will provide insight for researchers with an interest in geology, igneous petrology, geochemistry and mineral resources. Hatton anglo american research laboratories pty ltd. Platinumgroup elements in the upper zone of the rustenburg layered suite of the bushveld complex. This file contains additional information such as exif metadata which may have been added by the digital camera, scanner, or software program used to create or digitize it.
Nov 17, 2007 a new geological map of the rustenburg layered suite south of the ysterbergplanknek fault of the northernpotgietersrus limb of the bushveld complex is presented, displaying features that were not available for publication in the past and are considered contributing to the complexity of this region. Platinum group metals files wbjv project 1 technical report. In fact, bushveld by itself is a large igneous province lip according to criteria of bryan and ernst 2008. Jan 31, 2018 an intrusive origin of some ug1 chromitite layers in the bushveld igneous complex, south africa. Reichardt, 1994 gives an estimated volume for the molopo farms complex of 200 000 km3. North west, gauteng, for the western limb and limpopo and mpumalanga for the eastern limb.
The zonal nomenclature of the bushveld complex relegated to informal status by the south african committee for stratigraphy 1980, is reinstated and redefined using a hierarchy of zones, subzones. Construction expos in south africa recommended for you. The complex consists essentially of five adjoining, basinshaped masses of igneous rocks. Platinumbearing chromite layers are caused by pressure. To investigate this possibility we derive a robust new estimate of the major and trace element bulk composition of the bushveld upper zone and upper main zone uumz. Geological map of the bushveld complex and surrounding rocks. Geospatial mapping of the northern bushveld rustenburg. Effect of time on the tensile strength of several bushveld complex rock types iv abstract despite observations of spalling and damage of bushveld complex bc mine excavation wall rock over the passage of time, there have been very few timedependent or creep tests carried out in south africa on rock, particularly on bc rock.
Upb geochronology documents outofsequence emplacement. With on the order of 1millionkm3 of igneous rocks, the bushveld igneous complex is by far the worlds largest igneous intrusion, preserving a unique record of magma chamber processes on a truly grand scale. The geomorphological history of the bushveld basin gave rise to four discrete physiographic regions found in the study area. Geological setting university of the witwatersrand. Kinnaird school of geosciences, university of the witwatersrand email protected eous complex compiled by judith kinnaird, johan moose kruger and paul nex economic geology research institute, school of geosciences, university of the witwatersrand. The geology is described briefly assuming familiarity on the part of the reader and the contents of this issue and some earlier reports are summarized. Bushveld complex geological formation, south africa. Bushveld igneous complex, south africa aster image gallery. In south africa, an enormous layered intrusion, containing over half the worlds platinum, chromium, vanadium, and refractory minerals. May 19, 2015 the mafic rocks of the bushveld complex, south africa, were emplaced into a stable cratonic shield some 2. The bushveld complex, a product of interaction among magmas derived from a mantle plume c. Abstractrheniumosmium isotope measurements of selected chromitites from the critical zone of the bushveld igneous complex reveal that a signi. Upb geochronology documents outofsequence emplacement of. The bushveld episode was evidently initiated by the outpouring of andesitic lava on three occasions, and of agglomerate and tuff on one occasion, during the deposition of the transvaal system.
The bushveld igneous complex bic is the largest layered igneous intrusion within the earths crust. Nov 14, 2016 upb geochronology documents outofsequence emplacement of ultramafic layers in the bushveld igneous complex of south africa james e. Keywords northern bushveld complex, rustenburg layered suite rls, regional trends, residual structures, igneous layering, trend surface analysis 1. Upb geochronology documents outofsequence emplacement of ultramafic layers in the bushveld igneous complex of south africa james e. Most of it comes from a geological formation the size of west virginia, called the bushveld igneous complex, created two billion years ago as molten lava from earths mantle bubbled to the surface and cooled. The bushveld complex, as exposed at cur rent levels of erosion, consists eastern, western and northern limbs, see figure 1, and is some. Measured 187os188os ratios increase with stratigraphic height, and individual. Download pdf layered intrusions free online new books in. Introduction to the bushveld complex, south africa the bushveld complex, of palaeoproterozoic age, is located in the central northeast portion of the kaapvaal craton in southern africa, and has an estimated total area of 65 000 km2 hunter, 1976.
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