PPM Annual Report 2010 The Annual Report for the Paleoproterozoic Mineralization Research Group

department of geology UNIVERSITY OF JOHANNESBURG The Annual Report of the Paleoproterozoic Mineralization Research (PPM) Group, compiled and edited by HM Rajesh and Nic Beukes. Layout and design by HM Rajesh and the UJ Graphic Studio.

Special thanks/Acknowledgements We wish to extend a special word of thanks to all of our corporate and governmental financial supporters (in alphabetical order): African Rainbow Minerals Anglo American Anglo Coal Anglo Gold Ashanti Anglo Platinum Anglo Research Assmang Assore Coaltech Department of Science and Technology (DST) Lonmin National Research Foundation (NRF) Nkomati Joint Venture Rand Uranium (Gold One) Salt River Resources Ltd

Please direct all enquiries and applications for research to: Prof. Nic Beukes or Prof. Fanus Viljoen PPM, Department of Geology University of Johannesburg Auckland Park Kingsway Campus PO Box 524, Auckland Park 2006 Johannesburg, South Africa E-mail: [email protected] or [email protected] Tel: +27 (0) 11 559 4712/4710/4711 Fax: +27 (0) 11 559 4702 http://www.uj.ac.za/geology

Cover photo: View of the Bokkeveld (in foreground) and Witteberg strata of the Cape Supergroup at Gamkapoort Dam, Western Cape Province INTRODUCTION The PPM Research Group, formed in 1997 as an informal research group in the Department of Geology, has for the past four years been officially recognized by Management of the University of Johannesburg as one of the Research Centres of Excellence at the University. This meant that PPM received an annual research grant from the University Research Committee to strengthen the group especially with respect to funding salaries of support staff and providing additional bursary support to postgraduates and postdoctoral associates. A review of the research centres took place during 2010 and PPM was in the fortunate position to be awarded support funding for another three-years from 2011 to 2013, after which outputs shall again be reviewed. As part of the additional support from UJ we were able to appoint several new postdoctoral fellows in PPM. The funds also made provision for appointment of Profs Jan Kramers and Nic Beukes (who officially retired at end of 2010) on contract basis for another three years. Axel Hoffman joined the Department of Geology and PPM during August 2010. With this appointment the PPM Research Group further strengthened the research niche into the field of early Precambrian environments, especially origin of early life. Geometallurgy figured prominently in the research topics initiated by new students. New research projects were launched on the characterization of strategic minerals – PGE- and REE-bearing minerals. Prof. Nic Beukes again received an Al rating from NRF for another five year cycle that started in January 2010. During 2010, research focused in five main areas, namely geometallurgy-kimberlite research, metalliferous mineral deposits, paleomagnetism-provenance studies, early Precambrian environments and coal geology (see diagram below). In addition Prof Bruce Cairncross continued work on geoheritage research.

PPM Research Group (2010) Staff and Students Leaders of the research group Prof. Nic Beukes, Prof. Fanus Viljoen Staff Members Prof. Bruce Cairncross, Dr. Michiel de Kock, Mr. Michael de Villiers, Prof. Jens Gutzmer Prof. Axel Hoffmann, Prof. Jan Kramers, Mr. Mike Knoper, Dr. Hassina Mouri, Prof. HM Rajesh, Mr. Bertus Smith, Dr. Herman van Niekerk

Geometallurgy, Metalliferous Paleomagnetism, Kimberlite Research Mineral Deposits Provenance Studies

Team Members Team Members Team Members Ms. A Crossingham Mr. B Chisonga Mr. R da Silva Ms. G Mishra Mr. F Kruger Ms. D Dreyer Ms. S Mkhatshwa Mr. T Mabundza Mr. P Fourie Ms. L Mngoma Mr. B Nel Ms. M Peche Dr. C McClung Mr. K Osburn Ms. C Vorster Mr. D Pretorius Mr. JC Beyeme-Zogo Mr. H Wabo Dr. B Richards Mr. D Rose Mr. F van der Merwe

Coal Geology Early Precambrian Technical Support Environments Staff

Team Members Team Members Mr. M Chakuparira Dr. H Tsikos (Rhodes) Mr. GA Belyanin Mrs. D Khoza Mr. P Meyer Mr. A Gumsley Mr. L Mangwane Mr. B van der Walt Mr. B Guy Mr. M Watts

1 PPM group members in the meeting room of the Geology Department RESEARCH PROGRESS AND HIGHLIGHTS Growth in geometallurgical research at the University of Johannesburg As the world demand for metals the mineralogical and textural associated silicate, oxide and sulphide increases, the focus changes to lower- characteristics of ore bodies, ores, minerals, in relation to metallurgical grade or problematic deposits that concentrates and successor products issues during the recovery of platinum- would not have been mined in the past. in resource types relevant to the South group elements. Research is also Without a thorough understanding African minerals industry. Research focussed on geometallurgical aspects of of the mineralogical constraints (i.e. is focused on the characterisation of gold, diamond, nickel, the base metals variations in mineral compositions, size, platinum-group element mineralisation (copper-lead-zinc), coal and lime, with morphology, mineralogical associations, within the Merensky Reef and the a view on the optimisation of treatment impact of grind size on liberation and Plat Reef of the Bushveld complex, plants and optimised metal recovery. the reason for deportment of minerals utilising mineralogical and geochemical During 2010 papers were presented by in certain streams) interpretation techniques such as X-ray diffraction Geometallurgy students and staff at the of metallurgical test work could be analysis, scanning electron microscope- Geological Society of America Meeting flawed. This highlights the necessity based automated mineralogy, and in Denver, Colorado, the Society of for conducting in-depth mineralogical, electron microprobe analysis. Research Economic Geologists Conference petrographical and mineral chemical into automated mineralogy as applied in Keystone, USA, the International investigations in order to obtain a better to the characterisation of ores and ore Mineralogical Association Conference understanding of the metallurgical bodies is conducted on a ‘state-of-the- in Budapest, Hungary, and the Process behaviour imparted by these ores. art’ FEI 600F Mineral Liberation Analyser Mineralogy 2010 Conference in Cape The primary thrust of the geometallurgy at UJ. An example is the determination Town. Five MSc projects, six PhD group is to develop and apply of the mineralogy of various ores of the projects, and one post-doctoral project geometallurgical methods to quantify platinum-group elements, along with is currently in progress.

Some of the geometallurgy group members at the IMA meeting in Budapest, Hungary

2 Metalliferous mineral deposits Research on the iron ore potential of During 2010 we took part in ores deposits. The third workshop, co- the Asbestos Hills region in Griqualand presentation of three workshops on organized by the Universities of Brasilia West continued during 2010. The main banded iron formation and associated and the Federal University of Ceara, was aim of this project is to establish the iron ores. The first was at PDAC held in Fortaleza, Brazil towards the end high-grade iron ore potential of the in Toronto, Canada during March of November 2010. The main presenters region outside of the area of the known 2010 where Jens Gutzmer, Joydip at the workshop were Michael Bau from high-grade BIF-hosted hematite iron Mukhopadhyay and Nic Beukes Jacobs University in Germany and Nic ore deposits of the Sishen-type on the presented talks on the iron ores of Beukes. Michael Bau was responsible Maremane Dome. In addition research southern Africa and India as well as for presenting geochemical aspects of is also undertaken on low-grade iron models for the origin of high-grade BIF- iron formations while Nic presented ores and banded iron formation of hosted iron ores in general worldwide. two afternoon lecture series on the the region to establish their potential The second workshop took place at sedimentology of iron formations, for beneficiation to saleable iron the University of Minnesota in Duluth high-grade iron ore deposits and ore products. Another project aims during October 2010. It was the Fourth the classification, nature, origin and at characterizing high-grade small Professional Workshop organized by paleoenvironmental significance of magnetite ore bodies and associated Precambrian Research Center of the Precambrian manganese deposits. The supergene-modified hematite ore University of Minnesoata in Duluth and workshop was followed by a weeklong bodies in the Mesoproterozoic Gams focused on BIF and associated ore field trip to Archean and Proterozoic Formation of the Bushmanland deposits. As one of the invited lecturers iron formations and associated rocks to succession in the Namaqua Nic Beukes presented a seminar on BIF- the southeast of Fortaleza. Metamorphic Belt. hosted manganese and high-grade iron

Nic Beukes with students and staff of the Universities of Brasilia and Ceara that attended a field excursion to iron formations southeast of Fortaleza in Brazil. Co-presenter of the workshop, Michael Bau, is in the back row second from right

Delegates of the Duluth BIF Workshop workshop looking at what appears to be a channel-fill of granular iron formation in banded lutitic iron formation at one of the iron ore mines in the Mesabi Range, Minnesota

3 Developments in Geoheritage Recent developments in geoheritage out that rare geological specimens, and multiple rarity factors can apply to research can be summarized by the considered as portable geoheritage single specimens. A lack of clear criteria question - why publicize South Africa’s specimens, are neither defined nor for defining rare geological specimens mineral heritage? It is non-renewable, described in the National Heritage appears to place the National Heritage it has scientific value (type-locality Resource Act (1999), making their Resource Act (1999) in direct conflict species, parageneses, geometallurgical geoheritage status questionable. He with the more recent Mineral and value), it has beauty and diversity and further points out that geological Petroleum Resources Development mineral collections can be draw-cards specimens (resources) are complex Act (2002) which legitimizes the legal at museums. Bruce Cairncross points objects when defining their rarity status exploitation of any mineral resource.

Bruce Cairncross underground in the N’Chwaning II manganese mine, Kalahari manganese field (left). Rhodochrosite specimens from the Kalahari manganese field - the front left stone is 17.5 carats (photograph by Bruce Cairncross) Contribution to SEG Student Chapter Ashley Gumsley, a Masters student in as Chairman, Ashley was selected by deposits of the Tintic Mining District PPM was voted Chairman of the SASC- the Society of Economic Geologists in the basin-and-range of Utah and SEG (South African Student Chapter for (SEG) to participate in the annual SEG included the Bingham Canyon copper- the Society of Economic Geologists) for Foundation Student-Dedicated Field molybdenum-gold porphyry mine. The 2010. The membership consists mainly Trip Course across the western United uranium-vanadium-copper roll-front of geology students from the University States, entitled: ‘Ore Deposits of deposits of the San Rafaél Swell district of Johannesburg and the University of Utah and Colorado’. The field course were also viewed together with the the Witwatersrand. During his tenure emphasized the geology and ore stratigraphy of the Colorado Plateau.

Bingham Canyon Cu-Mo-Au porphyry mine, the world’s largest man-made excavation (left). Ashley on the Colorado plateau with the San Rafaél reef in the background (right)

4 Developments in the noble gas laboratory at UJ Jan Kramers The MAP 215 noble gas mass use it for dating of soil authigenic The extension to U-Th-He dating spectrometer and extraction line with minerals such as components of has entailed developments on the 1064 nm continuous Nd-YAG laser ferricrete, and speleothems. This is extraction line. Of the twin, originally became operational in July 2010 a pioneering approach, and will be identical laser ports, one was equipped following minor repairs and alignment applied in geomorphological studies with a sapphire window (impermeable of the laser. George Belyanin has as well as in the dating of hominin to He) and a liquid nitrogen cold trap joined this laboratory as a postdoc fossil-bearing cave deposits. The containing activated charcoal granules, following submission of his PhD thesis. extreme sensitivity of the instrument to be dedicated to He extraction, The first batch of samples for Ar/Ar and low blank of the line allows very whereas the second remained small quantities of radiogenic He dating, comprising amphibole and unmodified, with a quartz window, and to be accurately measured. This will stilpnomelane separates mainly from dedicated to Ar extraction. Further, a enable dating of relatively young (a the western Transvaal Supergroup and 3He spike reservoir is being added. few Ma) mineral grains containing the Central Zone of the Limppo Belt, is The 3He tracer and a calibrated volume moderate amounts (around 1 ppm) about to be dispatched to Pelindaba vacuum pipette were donated by the for irradiation. We have carried out of U and/or Th. Following published reports that aragonite, hematite and noble gas laboratory of the University of degassing experiments on unirradiated Heidelberg, Germany. grains of these minerals to evaluate goethite are retentive for He at ambient whether they would be datable, to temperatures, experiments were carried Further, a completely new software chart step-heating degassing behavior out which demonstrated that samples suite is being written to operate the of these minerals would most probably and plan optimal analytical protocols mass spectrometer and reduce the be datable down to a few hundreds of for when the irradiated samples are data. This was necessary because the thousands years – thus bridging the returned for dating. existing software was unable to stabilize gap between geochronometers of the the magnetic field at low masses such In addition to preparation for the Ar/ geological time scale such as Ar/Ar and as required for helium, and desirable Ar dating application, the unit has been U-Pb, and the ones applicable to the from the point of view of having a more further developed to enable U-Th-He archaeological time scale, such as U/Th, interactive and experiment-oriented dating. This method is normally applied OSL, and 14C dating. Two projects, one environment. to low-temperature thermo chronology in cave dating and one in landscape using apatite, but our intention is to evolution, are currently being initiated.

Jan Kramers, Mike Knoper and post-graduate students at the Ar-Ar facility

5 Field excursion through southwestern US examining different extensional geologic features Mike Knoper

Mineralization is often associated with the annual Geological Society of New Mexico. This is one of the crustal extension. A very well exposed America (GSA) meeting held in Denver. youngest basalt flows in the Basin and region to study features associated Before commencement of the GSA Range Province, and erupted from with crustal extension is the Basin and annual meeting, the four PPM members numerous vents during the Holocene at Range Province, a broad continental met in Socorro, New Mexico. Starting different times between 5,000 and 1,500 rift that has stretched the crust to twice there, Mike Knoper, Craig McClung, years ago. The basalt flow examined its original width, in southwestern Bryony Richards, and Ashley Gumsley during the field excursion was a well North America. There extension began spent five days on a field excursion preserved example of pahoehoe after the Laramide Orogeny during through the southwestern United lava (see figure). The next stop was the Tertiary and as the San Andreas States. The purpose of the excursion White Sands National Monument in Fault (in California) developed, with was to examine features associated with New Mexico. Here gypsum that has extension continuing up to the present extension in New Mexico and Arizona; precipitated in the many salt pans day. Associated with extension of the specifically the Rio Grande Rift (located found in half grabens is accumulating as Basin and Range Province is the Rio in New Mexico), the Rincon Core wind-blown sand dunes. Shortly before Grande Rift, numerous core complexes, Complex (outside Tucson, Arizona), and the visit, precipitation associated with sedimentation, and bi-modal volcanism. the Buckskin-Rawhide detachment fault cold front had ponded in many areas With this background in mind, four (located in western Arizona). in the Monument, which provided a members of the PPM Research Group One of the first stops was to examine spectacular backdrop of distinct white arrived in the United States to attend the Carrizozo basalt flow near Carrizozo, dunes (see figure).

White sand gypsum dunes at the White Sands National Monument in New Mexico The group then carried on to Tucson gneiss, fine-grained microbreccia, and west of the Colorado River. Many of where they arrived in the late evening. then the detachment fault itself, and the features found in the Rincon Core On the following day, the Rincon Core finally the overlying non-mylonitic and Complex were also identified in the Complex was next on the itinerary. non-cataclastic rocks. Continuing with footwall of the Buckskin-Rawhide The purpose of visiting this locality the core complex theme, the group detachment fault, except the latter was to gain a clear understanding travelled to Swansea, an old ghost town feature includes copper mineralization of the fundamental components located in the western Arizona desert. and abundant specular hematite. After of metamorphic core complexes. Here, copper mineralization is thought spending a day in Swansea, the group From bottom to top, first seen was to be associated with fluid activity on continued to the GSA annual meeting mylonite and ultramylonite derived the Buckskin-Rawhide detachment in Denver, with stops along the way from quartz monzonite, chloritically fault, which is associated with a number at the Grand Canyon and at the Black altered microbrecciated mylonite of metamorphic core complexes just Canyon of the Gunnis.

6 HIGHLIGHTS OF RESEARCH FOCUS AREAS MLA based assessment of mineralogical variability of the UE1A, A1 and A5 reefs at Cooke Section, Rand Uranium properties Sindile Mkhatshwa One of the challenges faced by mineralogical variation within the of the Witwatersrand Supergroup. Rand Uranium Gold Mines in the reefs and within the region. A total The main orebodies that are Cooke section area, is the difficulty in of 133 reef samples, consisting of the exploited at the mines occur within differentiating between the various reef Elsburg UE1A, A1 and A5 reefs have the Gemsbokfontein Member of the types by means of their macroscopic been obtained from Cooke 2 and 3 Elsburg Formation. These orebodies characteristics. It is virtually impossible (two of the three Rand Uranium Mines) have been deformed into an east-west to differentiate between the various using the conventional chip sampling trending anticline at Cooke 3. The reefs visually; hence a study based on present study also attempts to prove or method. the use of mineral liberation analyser disprove the equivalence of the UE1A (MLA)-based automated mineralogy The mineralization in this area is hosted reef on the western limb of the anticline was carried out to distinguish between by the upper (dominantly alluvial to the A1 or A5 reefs on the eastern the various reefs and to assess the quartzite-rich) Central Rand Group limb of the anticline using mineralogy. Representative splits of the samples were subjected to mineralogical abundance quantification as possible through quantitative MLA-based modal abundance protocols such as XMOD. A standard file on the various mineralogical phases encountered, was created on the 600F MLA and complemented by quantitative XRD data. Mineral abundances were quantified by MLA, which works by backscatter electron (BSE) images and energy dispersive spectrometry (EDS) analysis, using sophisticated automated image analysis techniques. The various phases are distinguished from each other through their grey-level variations within BSE images (as grey-level is a reflection of the mean atomic number of the respective phase). Thirty two minerals have been detected using the MLA and they include phases such as quartz, pyrophyllite, chlorite, brannerite and pyrite.

Backscatter electron images of (a) flyspeck-carbon enclosed by brannerite, (b) galena associated with pyrophyllite, (c) uraninite occurring with carbon, (d) zircon associated with quartz, (e) uraninite in association with xenotime and pyrite and (f) pyrophyllite associated with arsenopyrite and brannerite

7 MLA based mineralogical assessment of gold and uranium mineralization at Cooke Section, Rand Uranium properties Lethuxolo Mngoma

Backscatter electron image and segmented particle image from the MLA indicating mineral associations for the phases of interest gold (a, and b), uraninite (c) and brannerite (d) The use of automated quantitative down to 80% passing 75 µm. Some of uraninite (see figure). From the modal mineralogical (MLA) techniques the samples were taken in for grade abundance one was able to gather has become increasingly important analysis in the various size fractions and that these minerals are associated for minerals processing, recovery some were taken in for heavy liquid with pyrite (which accounts for more and geometallurgy as a whole. The separation, in which the slimes, sinks 75% of the mineralogy in the sinks for speed and accuracy with which these and floats were analysed. From the all four samples), arsenopyrite, heavy SEM-based automated technologies information gained from the assaying, minerals, quartz, and other silicates. perform, has meant that the time and 30mm flat resin mounts (polished Other data gained from the analyses costs of analysis are greatly minimised. blocks) were made. These blocks were were, for example, information on An MLA-based study has been of the sinks and from the pulp or feed the size frequency distributions and employed for the assessment of gold material. mineral grade recovery. Grading and uranium mineralisation on the Two types of searches were conducted, analysis indicate that gold is mainly gold-and uranium-bearing reefs of the a sparse phase liberation (SPL) search coarse (>+75 µm) in all the samples. upper Witwatersrand Supergroup in a on the gold and uranium species, The inverse was noted for uranium deportment study. and given the abundance of the minerals, these were found mainly in In the sampling phase, the UE1a, uranium species, it was advisable to the finer fractions (<+53 µm). Mineral A5 and A1 reefs were sampled from run the XBSE mode which is ideal for liberation data indicates that only 17% Rand Uranium’s Cooke 3 Shaft. From investigating the pulp feed. The blocks of the brannerite, 27% of the uraninite the twelve sampled panels, four were were run at a 350 x magnification on and 50% of the gold is liberated. This chosen for the deportment study. The both the SPL_lite and XBSE modes. implies that the majority of the mineral four chosen panels were deemed to The following was observed: As grains are locked in the sulphides be representative of the mined reefs. expected gold was present along with which account for a large fraction of the These samples were milled and crushed two uranium species, brannerite and observed mineralogy.

8 Silicate and platinum group mineral characterization of chromitite stringers from the Merensky Reef, Two Rivers Platinum Mine Derek Rose This study focuses on the Merensky An84. This wide range in plagioclase chalcophile and siderophile elements. Reef (MR) at the Two Rivers Platinum compositions is believed to be as a Chromite chemistry and modal analyses Mine property on the farm Dwarsriver result of the increased presence of fluids of Merensky Reef secondary silicate 372 KT, in the southern sector of the within the Merensky Reef interval. The phases, which peak adjacent to the Eastern limb of the Bushveld Complex. hanging wall plagioclase compositions chromitite stringers, suggests elevated The cryptic variation of orthopyroxene, range from An64 to An84. fluid overprinting within and adjacent plagioclase and chromite, from five In situ platinum-group mineral to the chromitite stringers. However, exploratory drill core intersections (PGM) assemblages associated with the upper chromitite stringers have through the Merensky Reef at and adjacent to the Merensky Reef higher abundances of PGM phases Dwarsriver are described in this study. chromitite stringers were evaluated that are believed to be secondary in Locally the vertical cryptic variation of using an MLA. Data obtained from origin (see figure) relative to the basal these minerals is broadly consistent this technique is in broad agreement chromitite stringers. Generally the PGM with regional trends of the Rustenburg with regional studies of the Merensky associated with the upper chromitite Layered Suite (RLS). Reef. With the aid of whole rock stringers are also larger in size (see The lateral variation along strike is platinum-group element (PGE) assays figure) averaging 70 µm as opposed less pronounced than the vertical the MLA technique has proven to be to 27 µm for those associated with the cryptic variation. However, locally a powerful tool in evaluating PGM basal chromitite stringers. The increase these minerals appear to be chemically assemblages relatively quickly, from in grain size of the PGM along with the evolving moving from north to south on a few carefully selected samples. The higher modal abundance of secondary the property. Footwall orthopyroxene mineralogical associations of PGM PGM phases associated with the upper compositions vary from a minimum of with the gangue and host minerals stringers (see figure) is believed to be as En66 and reach a maximum of En84. have shown three main associations, a result of fluids. These fluids, although Those of the Merensky Reef range namely with chromite, base metal affecting both the upper and basal from En71 to En85. Hanging wall sulfide (BMS) and silicates. Finding chromitite stringers, appear to have orthopyroxene compositions range of the BMS association is remarkable had a relatively higher influence on the from En60 to a maximum of En80. given that the sulfide have a relatively upper chromitite stringers. The most Plagioclase compositions in the footwall low modal abundance. The relatively common PGMs encountered in this units range from a minimum of An69 high mineralogical association of the study are isoferroplatinum, sperrylite, and reach a maximum of An85. Those BMS with PGM has been explained michenerite, maslovite, cooperate, of the Merensky Reef range from a by a model involving a base metal laurite and braggite. minimum of An35 to a maximum of sulfide liquid which possibly scavenged

Stacked 100% histograms showing the dominant and subordinate PGM + Au assemblages associated with (a) the upper – and (b) basal chromitite stringers as a function of the total area of the upper and basal chromitite stringer populations respectively. n = grain count

9 Grain size distribution of the PGM + Au for the upper (red curve) and basal (green curve) chromitite stringer populations, also shown is the average grain size distribution for the entire PGM + Au (blue curve) population

Stacked 100% histograms showing the modal proportions of the pooled populations for (a) the upper – and (b) basal chromitite stringers respectively. The data was acquired using the XMOD procedure on the MLA

10 Geometallurgical characterization of the Main Mineralized Zone at the Nkomati Nickel Mine, Mpumalanga Gargi Mishra

This study aims to carry out a with the lower pyroxenite (fine- These textural variants are largely geometallurgical characterization of medium grained). controlled by the nature (mineralogical the different ore types at the Nkomati • Bleb and Net texture - associated composition) of the host rock, as well Ni-Cu-Co-PGE deposit located within with coarse-grained pyroxenite as grain size and the total amount of the Uitkomst Complex. Based on • Bleb-disseminated-semi net texture - sulfide mineral present. The dominant core logging and petrographic study associated with pyroxenite. sulfide minerals are pyrrhotite, of selected boreholes from Pit 3, the • Massive to Semi-massive texture - pentlandite, chalcopyrite and pyrite, textural variation of the sulfide ore observed occasionally associated while the host rock mineralogy in the main mineralized zone can be with pyroxenite. comprises of olivine, pyroxene, summarized as: • Hybrid-mix of calcsilicate and serpentine, calcite and plagioclase. • Net texture - this includes both fine pyroxenite with and without sulfide and coarse net texture associated mineralization.

Core samples illustrating the main sulfide textures

11 Based on the textural classification, It is observed that in a typical rock with it dilutes the concentrate, and may even a number of samples were selected pyrrhotite-pentlandite-chalcopyrite depress the flotation of other minerals. on which to conduct bench-top composition (see figure), chalcopyrite However, chalcopyrite appears to rougher flotation tests. From these, the is the first mineral to float, followed by be unaffected due to its strongly concentrates and tailings were analyzed pyrrhotite and then other ore minerals hydrophobic nature and rapid flotation for Ni, Cu, MgO and SiO2, Fe, AL2O3, and silicates with minor sulfides and kinetics. Detailed mineralogical study is S and Cr2O3, in order to generate oxides i.e. magnetite (see figure). It is in progress to understand the flotation total recovery curves which can be also observed that when talc (a naturally behavior of each of these minerals, as interpreted in terms of ore mineralogy. flotable mineral) is presents in the rock well as their liberation.

Example of a series of flotation froths obtained from a typical rock with pyrrhotite-pentlandite-chalcopyrite Nkomati ore. Chalcopyrite (1) is the first mineral to float, followed by pyrrhotite+chalcopyrite (2), then mainly pyrrhotite (3) and finally other ore minerals and silicates with minor sulphides and oxides (4)

Photomicrograph of pyrrhotite, pentlandite and chalcopyrite in ore from Nkomati

12 Preliminary exploration results from the Apiesdooringdraai ultramafic sill east of the Burgersfort bulge: Is it an economically viable Ni-Sulphide deposit? Themba Mabundza The Apiesdooringdraai sill east of nickel sulphide deposit. Some of the sample (~5% disseminated sulphides) Burgersfort bulge is a syn-Bushveld boreholes intersected disseminated from one of the earlier boreholes with intrusion, that is dominantly composed sulphide mineralization. Follow up the aim to determine how much nickel of harzburgite. The sill outcrops where work is being conducted currently by is potentially extractable from the Burgersfort town is situated and was BSC Resources. Airborne geophysics ultramafic sill. QEMSCAN was used historically mined for magnesite. (VTEM) was conducted recently over the for bulk modal analyses to identify and Exploration through diamond drilling project area and a number of anomalies quantify all minerals phases present on was carried out intermittently in the were identified and are currently being the sample. Selected mineral phases early 1970’s by Goldfield Mining drilled. A nickel deportment study was were further analysed by EPMA for their Development in the hope of finding a carried out recently on a mineralised nickel content.

VTEM survey over the project area. The pink outline represents the extent of the Apiesdooringdraai ultramafic sill

13 The bulk of the Ni (69%) is contained by pentlandite, with another ~1% by pyrite/bravoite. The pentlandite and pyrite/bravoite are closely associated with each other and often intensely intergrown. This indicates that most of the pyrite is most probably not pyrite (see figure), but bravoite, which occurs as an alteration phase of pentlandite. Only ~0.7% of the 1.0% contained nickel is extractable as the remaining 0.3% is hosted by gangue, mostly olivine and orthopyroxene. The project is ongoing and more data is being acquired with the current drilling programme. The boreholes drilled so far indicate that the sill is differentiated and this will require more studies on petrography and geochemistry.

Pentlandite is the main Ni host (~69%), with olivine containing the bulk of the remainder (~28%). The Ni content of olivine is low (0.50 mass% NiO), but it makes up nearly 80 mass% of the sample, while only approximately 2.0 mass% of pentlandite contains nearly 70% of the Ni, due to its high Ni content of nearly 36 mass%

Backscatter electron images (main) and QEMSCAN images (inset) of pentlandite (Pe & red) intensely intergrown with pyrite/bravoite (Py & yellow). The bravoite is most probably an alteration product of the pentlandite. Note the olivine (Olv), plagioclase (Plag), chromite (Chr), phlogopite (Phl) and clinopyroxene (Cpx) proximal to sulphides

14 Ni-Cu sulphide mineralization associated with gabbroic rocks from northern Japan Kazuyasu Shindo There are few known Ni-Cu-(PGE) include coarse-grained gabbro, olivine to surround these crystals in some deposits in northern Japan, of gabbro and norite. The gabbroic cases. The latter, which is relatively which some were mined in the past. rocks are considered products of rare, is semi-rounded and occurs in Although none of the mines are differentiation. K-Ar age of the gabbroic plagioclase, indicating that sulphide currently operating, research on Ni- complex is 35.3±1.1 Ma obtained was a liquid phase at the stage of Cu mineralization in mafic rocks is from biotite in norite. Ni-Cu sulphide plagioclase crystallization. Chemical very useful for not only elucidating ores are classified into disseminated composition of pyrrhotite is almost formation of these mineralization but and semi-massive based on their hexagonal (Fe7S8) with minor amount of also for future Ni-Cu-PGE exploration. mode of occurrence. Ore samples are Ni. The pentlandite compositions have The Oshirabetsu deposit, situated at composed mainly of plagioclase, with relatively higher Ni content than Fe and the southeastern part of Hokkaido lesser amount of pyroxene, amphibole, contain several wt.% of Co. Considering (northern Japan), is adjacent to the biotite, ilmenite, alteration minerals and the occurrence of sulphides with Main Zone of the Hidaka metamorphic sulphides. plagioclase, the gabbroic magma was belt. Metamorphism in the Main Zone Sulphide minerals comprise mainly saturated in sulphur at a relatively early corresponds to peak conditions of pyrrhotite with minor chalcopyrite and stage of crystallization. Sulphide liquids ~850°C at ~7.5 kbar related to gabbro pentlandite and traces of secondary first formed monosulfide solid solution intrusion around ~56-51 Ma, followed unidentified sulphides. Sulphide (mss) in the magma (briefly ~1100ºC). by reheating by an younger gabbro- minerals have two modes of occurrence With decreasing temperature, mss granite intrusion around ~23-18 Ma – as interstitial sulphides and as and residual sulphide liquid came and subsequent cooling to lower sulphide inclusions in plagioclase. to be sulphide minerals seen in the temperature and pressure conditions. The former has its grain boundaries rocks (i.e., pyrrhotite, pentlandite, and Rocks hosting Ni-Cu mineralization in contact with silicates and appear chalcopyrite).

Photomicrographs illustrating the different modes of occurrence of sulphides in mineralized gabbroic rocks from northern Japan. Top images illustrate interstitial sulphides and bottom images illustrate sulphide inclusion in plagioclase (shown by arrow) and silicate inclusion in sulphide. All the images except the top right image is in crossed polars. The top right image was taken under reflected light. Pl – plagioclase; Opx – orthopyroxene; Po – pyrrhotite; Cp – chalcopyrite

15 Oxidation of magmatic sulfides as explanation for elevated Cu/Fe in the Platinova Reef of the Skaergaard Intrusion (East Greenland) Cora Wohlgemuth-Ueberwasser The Skaergaard Intrusion (East fractional crystallization. To simulate the sulfide melt principally as FeO and/ Greenland) differs from other this third process, we equilibrated or FeO1.5 complexes. Oxidation with layered intrusions in that it contains a (Fe,Ni,Cu)1-xS sulfide melt with hematite is buffered by the fayalite- disseminated, stratiform Pd-Au oxidants like hematite and chromium magnetite-quartz (FMQ) equilibrium. mineralizations with up to 5 ppm Pd (VI) oxide in welded evacuated SiO2 Equilibration with CrO3 does not and 9 ppm Au. In comparison to classic glass capsules at temperatures ranging lead to a reaction with the glass disseminated sulfide-PGE horizons from 1050 (superliquidus) to 700°C capsule. The Fe1-xS component of like the Merensky reef in the Bushveld (subsolidus). Hematite reacts with the sulfide phase becomes oxidized Complex or the JM reef at Stillwater, the the FeS component of the sulfides by CrO3 under crystallization of Platinova reef occurs at a much higher, according to 2 FeS + 2 Fe2O3 = 6 FeO magnetite respectively chromite and chemically more evolved stratigraphic + S2, raising ƒS2 and sequestering FeO Cu/Fe ratios of the residual sulfide level in the cumulate pile in magnetite- to the sulfide melt. In the subsolidus phase increases significantly above 1. quartz-rich assemblages. region, the reaction is 6 FeS + 24 Fe2O3 Oxidation of sulfide is limited by the 2- 6+ Sulfide mineralogy is dominated by = 18 Fe3O4 + 3 S2, raising ƒS2 and transition of S to S , the sulfide- metal-rich Cu sulfides (bornite and stabilizing magnetite. The sequence transition, respectively. Equilibration chalcopyrite), and the noble metals of oxidation of sulfide species follows of a (Fe,Ni,Cu)1-xS sulfide melt with associated with the sulfide are Pd broadly the electromotive series, first natural anhydrite at elevated pressure and Au, mostly as alloys with (Cu,Fe) FeS, then NiS, and finally Cu2S and CuS, of 10 kbar using a piston-cylinder- (Au,Pd,Pt). Typical Fe-Ni-dominated eventually producing Cu-rich sulfides apparatus (picture below) changed the sulfides like pyrrhotite or pentlandite like bornite that coexist with metallic sulfide composition dramatically. All are absent. Two processes have been Cu, as observed in the Platinova reef. Fe and Ni was oxidized to magnetite suggested to explain Cu-enriched, Microprobe analyses of the first in equilibrium with Cu-sulfides and Fe-depleted Pd-Au-enriched sulfide experiments at 1050°C revealed a anhydrite. Any sulfide coexisting in equilibrium with sulfate should be Cu- horizons: 1) fractional crystallization of successive increase in oxygen (O2) sulfide like bornite or chalcocite. Our (Fe,Ni)1-xS monosulfide leading to Cu content in the sulfur melt at the expense experiments show that the Cu-rich enrichment in the derivative sulfide of S2, from < 0.5 wt.% (detection limit) sulfide assemblages as described above melt, and 2) modification of Fe-Ni- to 7 ± 1 wt.% O2 in charges with > 30 sulfides by infiltration of Cu-enriched wt% hematite. Iron also increases with for the Skaergaard type PGE deposits may be generated by a combination of postmagmatic fluids. A further possible increasing O2 content in the melt, explanation is sulfide oxidation during suggesting that oxygen dissolves in fractional crystallization and magmatic oxidation.

Piston-cylinder-press at the University of Muenster used for the anhydrite experiment. Charges can be equilibrated up to 2000°C 16 Different types of Mn-rich garnets from Singelele-type gneisses in and around Musina, Central Zone of the Limpopo Complex George A Belyanin The pink to orange colored Complex rocks near the type outcrop Singelele-type gneisses fall in the garnetiferous Singelele-type gneisses locality of the Bulai pluton on the farm field for magmatic garnets. In terms of constitute a long lived Neoarchean Macuville ~12 km northwest of Three garnet chemistry, three groups can be magmatic event (~2.72 – 2.56 Ga) Sisters, and Singelele-type gneisses distinguished. Garnets from Singelele- that affected the Central Zone of the representing both Paleoproterozoic type granitic gneisses SIN1 and SIN2 Limpopo Complex. This study presents event overprinted (represented by SIN4) (~2.64 Ga) are characterized by similar petrographic and mineral chemical and non-overprinted (represented by position on the diagram, very close to characteristics of garnet-bearing SIN3) rocks at the Causeway locality the Fe2+ corner, and contribute to the Singelele-type gneisses occurring in southeast of Musina, where meter-sized first group. Garnets from TR130 (~2.68 and around Musina. These include bodies of Singelele-type gneisses occur Ga) have similar composition as this Singelele-type gneiss samples collected interlayered and interfolded with rocks group. The second group consists of from a road cut along the Doreen- of the Beit Bridge Complex. the more Mg-rich varieties SIN3 and Musina road on the farm Ostend, east In addition to the common minerals RB24, whereas the overprinted gneiss of Musina (represented by TR130), (quartz, K-feldspar, plagioclase and SIN4 forms the third group (see figure). garnet-bearing leucocratic gneisses garnet), biotite and amphibole occurs Metamorphic garnets from metapelites (represented by SIN1 and SIN2) from in the Singelele-type gneisses collected from different parts of the Central the type locality at Singelele Hill near from the type-locality at Singelele Hill. Zone (green triangles in figure) are Musina, the Singelele-type gneiss In the Mg-Mn-Fe2+ ternary diagram characterized by significantly higher (represented by RB24) that intrudes the (see figure), garnets from the different Mg/(Mg+Fe) and lower Mn content. main gneissic fabric of the Beit Bridge

Mg-Mn-Fe2+ ternary diagram for garnets from the studied Singelele-type gneisses as well garnets from true metamorphic rocks in the Central Zone

17 Electron microprobe profiling of Paleoproterozoic overprinted gneiss lower (0.21) values. Garnet grains from Grt Grt garnet grains display constant XMg SIN4. In terms of XMg , Singelele- both gneisses do not display any zoning (= Mg/(Mg+Fe+Mn)) ~0.07 as well type gneiss RB24 is most similar to of Mg. At the same time, the zoning Grt as slight decrease of XCa (= Ca/ SIN3. Ca zonation in garnet is complex. of Ca is more complex and differs (Ca+Mg+Fe+Mn)) from core (0.11) to Moving from the core towards the in SIN3 and SIN4. In the latter case, Grt Grt rim (0.10) for Singelele-type gneiss rim a slight decrease of XCa is first XCa decreases from 0.18 (the value Grt TR130. XMg is either constant (0.07), observed, followed by an increase and, is the highest in the Singelele gneisses Grt or increases slightly from the core (0.03) finally again a decrease of CaX . This studied together with SIN1 and SIN2) in Grt to rim (0.05), while XCa = 0.15-0.16 for zonation pattern is characteristic of center of porphyroblasts to 0.12 at their Grt Singelele-type gneisses SIN1 and SIN2. all garnet porphyroblasts from RB24. rim, whereas in SIN3, XCa increases Grt The latter value is one of the highest XMg in SIN3 is the highest (0.32) in the from 0.05 to 0.12, and then decreases to in the Singele-type gneisses studied studied Singelele-type gneisses, while 0.07 at the rim Grt here, comparable only with XCa in the SIN4 is characterized by significantly

BSE images (a) and (c) and corresponding zoning profiles (5-5’ in b and 6-6’ in d) of garnet porphyroblasts in Singelele-type gneiss SIN-3 (a) and its Paleoproterozoic analog SIN-4 (c). In the zoning profile plots, left Grt Grt y-axis corresponds to XMg and right y-axis to XCa

18 Fluorite mineralization associated with lujavrite from the Mesoproterozoic Pilanesberg Alkaline Complex Sara Turnbull

The wide spectrum of minerals seen in Lurie reported fluorite as an accessory and accumulation. Trachytic texture due peralkaline igneous rocks like agpaitic mineral in all the major rock types to flow alignment of felsic and mafic nepheline syenites are important occurring within the complex. The phenocrysts are obvious in most of the repositories of large ion lithophile present project aims to characterize exposures examined. elements such as Na, K and Li, as well as the fluorite mineralization associated Preliminary electron microprobe the rare earth elements and high field with lujavrites from the Pilanebesberg analyses (carried out at SPECTRAU, UJ) strength elements such as Zr, Hf, Nb, Ta, alkaline complex. The lujavrite studied indicate the presence of alkali feldspar, U and Th. Magmatic or late magmatic here occurs as an arcuate ring-dike unit nepheline, aegirine and amphibole as to hydrothermal processes, or a in the southern part of the complex. the dominant minerals in the lujavrite. combination of both have been invoked Samples were collected from a series Albite- and sodalite-rich regions occur to account for the range of minerals of hillocks (outside the perimeters of in certain exposures. Other prominent seen in these agpaitic rocks. The the national park) covered with dense minerals, identified so far, which occurs Mesoproterozoic Pilanesberg agpaitic vegetation. Metre scale mapping of the as large crystals in hand specimens alkaline complex, emplaced into the lujavrite exposures indicate a very wide include eudialyte, astrophyllite and older Bushveld Complex, has reported range of textures and modes as a result fluorite. occurrence of fluorite mineralization. of flow differentiation, crystal sorting

Representative backscatter electron image from the lujavrite of Fluorite-rich vein in lujavrite from the Pilanesberg Complex the Pilanesberg Complex

Deep purple fluorite-rich veins cut these veins are dominantly made up of magmatic-hydrothermal fluids in across the general flow fabric of the of fluorite. The important role that the lujavrites, a fluid inclusion study is host rock (see figure). Such veins occur volatiles play during the generation, currently carried out in various minerals in different scales – from centimetre emplacement and crystallization of representing different stages in the to meter-scale. Unlike the fluorite alkaline rocks has been emphasized paragenesis. occurrence reported by Lurie, where it is by many authors. With the aim of mostly intergrown with other minerals, documenting the evolving composition

19 Structural setting of the Steenkampskraal monazite REE ore body Mike Knoper The origin of the Steenkampskraal monazite orebody within Mesoproterozoic Namaquan gneiss located near Kliprand in the northern part of the Western Cape Province (South Africa) has been attributed to magmatic emplacement under granulite- grade metamorphic conditions. This model explains the association of the monazite orebody with Qtz-Kfs-Pl-Grt-Bt-Opx dykes that intrude megacrystic granite-gneiss at Steenkampskraal.

A cross-sectional view, towards the east, of the Steenkampskraal monazite ore body. The trench in this part of the ore body is about 2.5 m deep, and a stope developed on the ore body occurs below the support timbers

To explain the structural setting the ore body. All folds rework and fold synformal flexures formed north and into which the dykes was emplaced, the gneissic banding (S2). However, it south of the ore body, and buckling structural measurements were obtained is notable that the monazite ore body instability nucleated along the obliquely from the monazite ore body and the is not folded similarly to the reworked inclined ore body. This resulted in the surrounding Namaquan gneiss. The gneissic banding (S2), implying that formation of the cuspate antiform (i.e., structural data reveal the presence of the ore body intruded after formation the Steenkampskraal steep structure) three F3 folds; from north to south: of the gneissic banding but before F3 found immediately north of the ore (a) an open synformal flexure north of fold development. First the ore body body. The implication of this data is the monazite ore body, (b) a cuspate was emplaced obliquely to the gneissic that the monazite ore body intruded antiform located immediately north of banding, and then upright F3 folds before F3 deformation, and that there the ore body’s surface expression, and developed by flexural-slip deformation is potential for an extension of the ore (c) an open synformal flexural south of of the gneissic banding. Two open body at depth.

20 Origin and emplacement of manganese with conglomeratic iron ore at the Beeshoek Iron Ore Mine, Northern Cape Province J-C Beyeme Zogo Beeshoek Iron Ore Mine, located old) sinkhole structures in underlying weight persent iron metal, with very 7 km west of Postmaburg in the dolomite of the Campbellrand low silica contents and only traces of Northern Cape Province, has two carbonate platform succession. In other elements. However, some of the sections referred to as North and South contrast the conglomeratic ores conglomeratic ore from the north pit open pit mines. Both mines produce represent ancient alluvium, derived from mine is enriched in manganese up to a high-grade hematite iron ore. Two the earlier supergene laminated ores, few percent Mn(II) oxide. The present main ore types are present, namely that accumulated in conglomerates at study investigates the emplacement of laminated and conglomeratic ore. the base of the overlying Gamagara manganese within the conglomeratic The laminated ore was derived from succession some 2 billion years ago. iron ore in the North pit mine. supergene enrichment of Kuruman iron Both ore types are typically of very high formation in ancient (~ 2,1 billion year grade, containing between 62 and 66

Hand sample of conglomeratic iron ore showing manganese oxyhydroxide infiltration (black) in porous laminae of large laminated iron ore pebble

Fresh samples of conglomeratic ore Mn(IV) oxyhydroxides that infiltrated dissolution of underlying manganiferous are composed of laminated iron ore into porous laminae in laminated ore dolomite of the Campbellrand pebbles in a matrix of hematite (see pebbles in the conglomeratic ore and carbonate succession. Dissolution figure). Results of this study indicated into parts of partly leached surrounding and karstification of dolomite are thus that the manganiferous conglomeratic hematite matrix (see figure). The ongoing processes as manifested by ores are always represented by ore manganese enrichment is thus related the highly disturbed and slumped material that has been subjected to to recent supergene mobilization of character of the ancient iron ores below weathering and supergene alteration manganese and emplacement into the modern or post-Gondwana African below the modern land surface. The conglomeratic ores. The manganese land surface. manganese occurs in the form of is most probably derived from

21 Mineralogical assessment of spatially associated iron formations in the Mesoproterozoic Gams Formation, Bushmanland Group, Aggeneys Area Fanie Kruger Metamorphosed iron formations are Investigations of the petrography and close to the present day land surface. hosted in the Gams Formation of the mineralogy of the Fe-oxide minerals The hematite is associated with a soft Mesoproterozoic Bushmanland Group. and the associated amphibolite-facies saprolitic highly chloritic alteration zone. In the Aggeneys-area these formations metasediments indicate that they Microchemical investigations by means share a close spatial and stratigraphic are characterized by a predominance of the electron microprobe of magnetite association with the stratabound, of magnetite and quartz. Garnets from different intersections of the polymetallic massive sulfide deposits of are present in distinct bands and Gamsberg Formation at Gamsberg the Aggenys-Gamsberg district of the some of these are conspicuously indicate that magnetite grains from Northern Cape Province. The iron-rich manganese bearing. Lesser quantities certain samples are chemically zoned rocks of the Gams Formation display of amphiboles were identified as well as with respect to Fe, Mn, and Zn content. macroscopic features that are very occasional occurrences of pyroxenes, similar to banded iron formations (BIF’s) pyroxenoids, and olivine. in general. This was also observed in the Within these iron formations there are iron formation that occurs at Gamsberg locally developed distinct ore bodies of (see figure). magnetite that are replaced by hematite

Example of metamorphosed banded iron formation of the Gams Formation at Gamsberg

22 Laser ablation ICP-MS dating of zircon populations from the Cape and lower Karoo Supergroups Clarisa Vorster The development of efficient methods determination of U-Pb ages of detrital means of monitoring the short term for the collection of U-Pb data for zircons, as these sequences represent a precision and accuracy attainable detrital zircon populations, as well gap in the global database, and filling during analytical procedures. Secondary as the meaningful interpretation of this gap will allow the reconstruction of zircon standards including GJ1 and results, has been the basis of many tectonic events and drainage patterns Temora-II, among others are also sedimentological studies worldwide of the Gondwana continent in the early incorporated during analysis. Currently, in recent years. Age determination of Phanerozoic. the internal structure of detrital zircon c. 30 µm regions of zircon grains was With regards to the method populations obtained from sediments first made possible by secondary ion development side of the project the of the Natal Group is being investigated mass spectrometry (SIMS) in the 1980’s, aspects involved in the establishment in preparation for detrital zircon age and then made more accessible by the of a reliable analytical protocol, dating. By establishing the U-Pb age cheaper, more widely available method capable of producing U/Pb data that of detrital zircons within the sediments of laser ablation inductively coupled are both accurate and precise have of the Cape Supergroup and related plasma mass spectrometry (LA-ICP-MS). been thoroughly investigated. The Natal Group, a correlation between The proposed detrital zircon study has careful optimization of both Laser- the sequences could be confirmed. two objectives: Firstly, the technique and ICP-MS operating conditions for Various tectono-sedimentary models of U-Pb zircon geochronology by the spot ablation of detrital zircons regarding the source of sediments in LA-ICPMS is to be developed and using a typical 30-60 µm spot size has the Cape – Karoo Supergroups, which optimized on the instrumentation been a main point of focus. Essential have been suggested in the past, could currently existing at UJ (A New-Wave fractionation corrections required for be re-evaluated and tested in the light UP 213 Nd:YAG laser coupled to a the meaningful interpretation of LA-ICP- of newly gathered U-Pb detrital zircon ThermoFisher X-SeriesII quadrupole MS data are conducted using the data age data. The study will further be ICP-MS). Secondly, dating of detrital processing software ‘GLITTER’, while extended to the sedimentary basins zircons from the sedimentary sequences common lead corrections are made in South America that are similar in of the Cape and lower part of the Karoo following the model Pb compositions age to the Southern African Cape and Supergroups are to be undertaken in an proposed by Stacey and Kramers. The Karoo basins, in order to test proposed effort to determine the source areas for U/Pb isotopic ratios obtained during correlations and constrain models of these sediments. This has the potential the ablation of the greatly homogenous sediment provenance on a broader to be an ideal study area for the 91500 zircon standard are used as Gondwana-wide scale.

View of the Dwyka Diamictite at the base of the Karoo Supergroup (in foreground) overlying strata of the Witteberg Group of the Cape Supergroup in the background near Matjiesfontein, Western Cape Province

23 Geochronology and correlation of Paleoproterozoic red beds of the Elim Group in Griqualand West, Northern Cape Province Daphne Dreyer This study was designed to assist in order to obtain better constraints on results are important for constraining the re-evaluation and/or confirmation the maximum possible ages of the the age of ancient lateritic weathering of the possible correlation of the various quartzite units in the succession profiles and timing of formation of the Mapedi/ Gamagara and Lucknow from detrital zircon age populations supergene Sishen-type high-grade BIF- Formations in the Griqualand West and in turn give a minimum age for hosted iron ore deposits developed basin to the Transvaal basin geology, the conglomerates associated with along the pre-Gamagara unconformity and to compare the composition of the red beds of the Olifantshoek and on the Maremane dome of the the Mapedi/Gamagara Formation Elim Groups, with specific focus on the Transvaal Supergroup in Griqualand above and below the Black Ridge Doornfontein Conglomerate Member West. thrust fault system. This is done in or pre-Gamagara unconformity. These

Doornfontein Conglomerate Bed, with boulders of iron formation and iron ore, at base of Gamagara/Mapedi succession, Rooinekke Iron Ore Mine

24 Multiple sulfur isotope signatures of diagenetic pyrite nodules in quartz pebble conglomerates of the Witwatersrand Supergroup and Ventersdorp Contact Reef Bradley M Guy

The occurrence of sedimentary pyrite recent multiple sulfur isotope study has reduction. Epigenetic pyrite grains (in- (or buckshot pyrite) as reworked and shown that pyrite in the Witwatersrand situ and reworked fragments), however, rounded fragments in quartzites QPCs was probably derived from both are characterized by attenuated δ34S, and conglomerates of the upper sedimentary and hydrothermal/igneous Δ33S, and Δ36S values, which are Witwatersrand Supergroup has been sources. distinctly different from sedimentary well documented, although the focus This investigation primarily focuses pyrite sulfur isotope signatures. has justifiably been centered on detrital on sedimentary pyrite, i.e., syngenetic Concentrically coated pyrite grain and epigenetic pyrite. Consequently, and diagenetic pyrite nodules in (CIS) or oolitic pyrite grains (see figure) very little attention has been given to auriferous conglomerate beds. These exhibit the largest negative δ34S reworked (endoclastic) pyrite nodules, specific paragenetic pyrite associations excursions. A depositional control on despite the fact that it comprises a act as geological black boxes and multiple sulfur isotope compositions large percentage of total pyrite in record biogeochemical changes is also apparent. Sedimentary pyrite several Witwatersrand quartz pebble in atmosphere, hydrosphere and grains from fluvial braidplain settings conglomerates (QPCs) and that it subsurface environment. A total of 47 are characterized by near-zero Δ33S contains elevated contents of Au and individual pyrite grains were analyzed values, which may indicate terrigenous Ag. Historically, the confined range from six different gold-bearing QPCs dilution. Pyrite grains obtained from of conventional sulfur isotope data or reefs (the Middelvlei, Basal, Vaal, transgressive marine conglomerates (δ34S) from Witwatersrand pyrite has Kalkoenkrans, Beatrix and Ventersdorp (that have reworked underlying fluvial lead authors to suggest a magmatic deposits) display both fluvial and Contact Reef). δ34S, Δ33S and Δ36S source of the pyrite sulfur. However, values range from -6.8 to +8.3 ‰, -1.7 to marine signatures (i.e., a trend towards recent laser ablation study has found +1.7 ‰ and -3.9 to +0.1 ‰, respectively. enriched δ34S values). These results larger fractionations in δ34S (-5.3 We found that multiple sulfur isotope suggest that low atmospheric oxygen to +6.7 ‰) and small-scale isotopic compositions vary as a function of concentrations prevailed during the gradients in sedimentary pyrite (see paragenetic pyrite association, pyrite deposition of the Witwatersrand QPCs, figure) – suggestive of bacterial type and depositional environment. but that local influxes of sulfur into sulfate reduction. The discovery of Syngenetic and early diagenetic pyrite the riverine environment attenuated mass-independent fractionation of nodules display the largest variations Δ33S anomalies and contributed to the sulfur isotopes (MIF-S) has provided abundance of sedimentary pyrite in the in δ34S, Δ33S, and Δ36S, and most geoscientists with new opportunities conglomerates that we observe today. examples display negative Δ33S to obtain further insights into the pre values, suggestive of microbial sulfate 2.4 Ga sulfur cycle. In this regard, a

Example of an oolitic pyrite grain from the Ventersdorp Contact Reef

25 Petrographic and geochemical characterization of modern sedimentary environments and geological units of the KaNyaka Island System, Mozambique Marieke Peché and Herman van Niekerk The KaNyaka (previously known as coastal plain of Mozambique with the present on the island and to obtain age Inhaca) island system forms a barrier Indian Ocean. The aim of this study is dates on some of the lithological units. island along the southeast coast of to identify and describe the lithological Age dating was performed on shell Mozambique. It is an extension of the and geochemical characteristics of fossils and calcareous root marks by large dune cordon that separates the modern and ancient sedimentary units means of the 14C method.

Main outcrop of the Cabo KaNyaka Formation on the northeast point of KaNyaka Island

Lithological studies suggest that the Ponte Torres Formation. It is composed exposed on the eastern side of the geological units of KaNyaka Island of calcrete with steep crossbedding island, and may be a lateral equivalent should be regrouped and classified and is exposed all along the west coast of the Ponta Raza Formation (3293±20 into five major formations, namely the of KaNyaka Island. The Cabo KaNyaka BP; 14Cage obtained dated from a sea Ponte Torres, Ponte Ponduini, Cabo Formation is made up of various ancient shell) – that is exposed on the western KaNyaka, Ponta Raza and Muamuluago dune systems that formed around 24 side of the island. Formations. The Ponte Torres 940 years ago (age obtained from a The KaNyaka island system also Formation, which consists of massive fresh water shell fossil) and may be a contains several modern sedimentary and flat bedded calcarenites, most lateral equivalent of the upper part environments, which can be roughly likely forms the eastern basement of the of the Ponte Ponduini Formation. It is classified into three groups. The island and stretches from the west of mainly exposed on the most northern sedimentary environments on the Saco KaNyaka, along the eastern coast tip of KaNyaka Island. The Muamuluago western shore of KaNyaka Island are of KaNyaka Island. The Ponte Ponduini Formation is an eroded dune system dominated by the tides and biogenic Formation is the oldest dated formation (with ages ranging between 3363±20 sedimentation, while those on the 14 (42130±860 before present; C age to 1802±20 before present; ages eastern shore are dominated by wave obtained from a fresh water shell fossil) obtained from fresh water shell fossils action, the northwards flowing off-shore on the island and appears to overlie the and calcified root marks respectively) current and the strong winds.

Map showing the modern depositional environments of KaNyaka Island, and 26 distribution of the five geological formations identified Preliminary geology of the Kolo kimberlite pipe, Lesotho Bryony Richards The Kolo kimberlite pipe is located 1575 metres at the base of the Kolo margin of the Kaapvaal Craton in the in the western lowlands of Lesotho at Mountain (2103 metres in elevation). southwestern Lesotho lowlands. The approximately S 29º 37’ and E 27º 19’, The Kolo pipe is a basaltic-type (Group Kolo kimberlite intruded along the roughly 38 km southwest of the nation’s 1) kimberlite, consisting of four lobes: contact between the Upper Beaufort capital, Maseru (within the Mafeteng central, east, north and northwest (see and lower Stormberg Groups of the administrative district), along the figure). The pipe forms part of the Karoo Supergroup and a late Jurassic international border with South Africa. much larger Sekameng-Kolo Kimberlite (Karoo) dolerite dyke. The pipe is small, The pipe itself is located on the flank of Group, a group of five pipes and eight approximately 1.2 ha and of low grade a ridge at an elevation of approximately southeast-trending dykes close to the ranging between 1.2-13.6 cpht.

Schematic map of the Kolo kimberlite pipe

The main kimberlite lithologies within facies kimberlite (10.8 cpht) and New data from probe analyses (see the pipe (see figure) are defined as comparatively low (1.2-5.8 cpht) within figure) has indicated that although hypabyssal-facies kimberlite (HFK), the diatreme-facies (DFK). Low grades hypabyssal and diatreme units were dominated by carbonated ilmenite- in the DFK are primarily due to internal emplaced in a single, discrete episode, phlogopite-bearing kimberlite and dilution by abundant country rock differing thermal regimes has allowed diatreme-facies kimberlite (DFK), xenoliths/inclusions (i.e. sandstone, for chemical differentiation and consisting of tuffisitic kimberlite breccia shale, dolerite, basalt and granitic morphological evolution of minerals. (TKB) and tuffisitic kimberlite (TK). In-situ gneiss). Diamond grades are noted to The aims of this study is to provide transitional zones (TKt, TKtB and HKt) differ between the different diatreme- the first published, petrological and between the hypabyssal and diatreme- facies lobes (DFK1; 5.8 cpht, DFK2; 1.2 chemical analyses of the different units facies are consistent with other reports cpht, DFK3; 2.2 cpht) indicating that of the Kolo kimberlite, to reclassify and of transitional-facies kimberlite (TFK) grade is not based on internal dilution expand on previous mapping work and and occur in several areas of HFK-DFK alone. The fact that the pipe crosscuts to do a detailed interpretation of the transition in the pipe. a Karoo dolerite dyke, indicates that it genesis and emplacement of different Recalculated diamond grades are was emplaced after the Early Jurassic kimberlite units. highest in the hypabyssal-facies between 87-95 Ma, coinciding with ages kimberlite (13.6 cpht) and transitional of other kimberlite pipes and dykes in Lesotho.

27 Possible post-Permian diatreme activity in the northeastern Karoo basin Byron van der Walt

Four anomalous borehole core Formation in the study area are the activity. A review of diatremes and their sequences from the northeastern occurrence of intrusive mafic dolerite mode of emplacement is proposed with Karoo Basin are examined for this sills and dykes, which are known to reference to their occurrence within study. The boreholes are located up have been contemporaneous with and the Karoo Igneous Province, as some to 30km from each other and are immediately following the eruption of diatremes in the Karoo are associated litohostratigraphically completely the Jurassic Drakensburg flood basalts. with dolerite sill emplacement. The atypical for coal bearing strata of the The borehole core lithologies have isolated occurrences, lithologies, Permian Vryheid Formation of the been described in detail with reference petrography, alteration and Ecca Group, Karoo Supergroup. The to their textural, mineralogical and geochemistry of the sequences will lithologies of the four boreholes are petrographic characteristics. Preliminary be used to argue that the Vryheid intensely brecciated for the most mineral and chemical data requisitions Formation, intersected in the form of part, while all of the surrounding are completed and geochemical the four anomalous boreholes, was boreholes reveal normal stratigraphy; investigations are in progress. Several disturbed by diatreme activity, which are their sedimentary strata are normally modes of origin of the breccias are genetically related to the late dolerite horizontal with no faulting present. The considered, with the primary hypothesis sill emplacement into the Karoo strata. only known disturbances to the Vryheid that the brecciation is due to diatreme

Examples of core from the brecciated borehole intersections in strata of the Vryheid Formation of the Karoo Supergroup

28 Paleomagnetic study of post-Transvaal sills and dykes in the eastern Kaapvaal Craton Herve Wabo In the Kaapvaal Craton, disagreement study, about 122 oriented cores were The first one is oriented north down between paleomagnetic poles obtained obtained from six sills (pyroxenite, (ND component) and is identified in from the Bushveld rocks and those norite, dolerite, and diorite rocks types), many of the sills as well as the dykes from units of Bushveld-age has long one east-trending pyroxenite dyke, from the Belfast and Lydenburg areas. presented a problem. In addition and eight NNE-trending dolerite dykes This ND component is believed to be rapid polarity reversals reported from near Belfast and Lydenburg (see locality primary, based on a positive baked the Bushveld Complex by Letts et figure). In addition, 5 oriented cores contact test. The ND paleopole al. (2009; Palaeomagnetism of the were also taken from one site of country overlaps with the 2.06 to 2.054 Ga 2054 Ma Bushveld Complex (South rocks for conducting a baked contact poles (see paleomagnetic results figure Africa): implications for emplacement test. A), suggesting that many of the post- and cooling; Geophysical Journal The paleomagnetic measurements Transvaal intrusions are related to a International, vol. 179, pp. 850-872) also were achieved using the new magmatic event of this age interval (i.e., remains to be explained. To investigate superconducting rock magnetometer the Bushveld Complex). Importantly, these problems, we sampled post- housed at UJ. Specimens were treated however, our pole doesn’t overlap Transvaal sills and dykes in the eastern using both low-fieldstrength AF (up to with Letts’ Bushveld mean pole (see half of the Kaapvaal Craton (see figure). 10mT) and thermal demagnetization paleomagnetic results figure A). In These intrusions are believed to be (from 100ºC to above 580ºC). addition, the absence of reversals in genetically associated with the ca 2.05 Paleomagnetic analysis reveals our ND directions may suggest that Ga BIC and represent rapid cooling the existence of four high-stability Letts’ pole might be representative of as opposed to the main complex (i.e., remanent magnetic components that a longer time period (i.e., protracted simpler magnetic history). For our unblock above 500ºC. cooling).

Paleomagnetic poles and VGP obtained from sills and dykes in this study compared to existing data from the Kaapvaal craton

The second high stability component is The third high stability direction, The fourth high stable magnetic shallow dual- polarity directions (North oriented east-down (ED component), direction, identified in one sill from and South) and is obtained from the is identified in one NNE-trending Belfast, gives a 180 Ma-like direction NNE-trending dykes from Lydenburg. dyke from Lydenburg. The VGP, (see paleomagnetic results figure B), These NS/SS directions are similar recalculated from this ED component, thus some post-Transvaal intrusions are to the directions from the ~1.1Ga plots near existing ~1.9 Ga poles probably related to the Karoo Large Umkondo dolerites (see paleomagnetic (see paleomagnetic results figure B), Igneous Province. results figure B). indicating that the NNE-trending dyke swarm hosts dykes of at least three discrete magmatic events.

29 The paleogeographic position of India during the break-up of the Mesoproterozoic supercontinent Nuna Michiel de Kock The configuration of continents in geochronological database. Compared limited paleomagnetic consideration. Earth history is becoming increasingly to this, ideas on the configuration of Geological similarities between eastern important for our understanding of the earlier Mesoproterozoic Nuna India and the Columbia region of North the changing Earth system through supercontinent are in their infancy. America promoted usage of the name time. Since paleomagnetism Nuna is usually represented around Columbia for this Mesoproterozoic coupled with precise isotope age the ‘Hudsonland’ juxtuposition of supercontinent. In addition India was data is the only method by which to Laurentia and Baltica. Siberia can be made part of the larger crustal block gain direct information on ancient fitted along the eastern margin of (i.e., Ur), which sees it essentially in a continental configurations, insufficient Laurentia and the Uralian margin of Pangean arrangement with respects paleomagnetic and geochronological Baltica to complete the acronym NENA to Proto-Australia, Madagascar, coastal data is the most significant problem (Northern Europe and North America) East Antarctica and Kalahari. India’s facing paleogeographic reconstructions. within Nuna. Other blocks (e.g., Proto- position, however, has subsequently The exact configuration of Rodinia, for Australia, North China, Amazonia, India, been significantly modified by other example, remains highly debatable, etc.) are usually tentatively positioned authors, which is why the name Nuna is but has generally matured over two around the NENA-fit based mostly given preference instead of Columbia. decades of scientific effort aimed at upon geological correlation and filling gaps in the paleomagnetic and

Proposed reconstruction of the supercontinent Nuna, which places India near the Columbia region of North America. This reconstruction is not geometrically accurate, and has been modified by various authors India’s position within Nuna has only been tested paleomagnetically at ~1770 Ma, and then via the “closest approach” method which allows considerable leeway in relative paleolongitude between India and other continental blocks. Since then new paleomagnetic data has become available. Combined with the recent acquisition of reliable paleomagnetic data and 1405 ± 9 Ma to 974 ± 8 Ma ages from carbonate sequences from the Penganga and the Chandarpur-Raipur groups, India’s position within Nuna can now be constrained more reliably via arc-length comparisons between similarly-aged poles from India and other continental blocks of interest.

Finely-bedded grey limestone of the Bhima basin, Karnataka, India

The new paleomagnetic data consists of six sampling sites and is supported by various field tests of paleomagnetic stability, which attests its primary nature. To enhance the quality of paleomagnetic poles obtained from India during the break-up of phase of Nuna, additional sites are to be sampled in early 2011 from the Kaladgi and Bhima basins of Karnataka in India.

30 Mafic- to ultramafic intrusions along the southeastern margin of the Kaapvaal Craton Ashley Gumsley The southeastern margin of the The ENE-trending dykes are massive, contemporaneous with the ca. 2985 Kaapvaal Craton in northern KwaZulu- fine- to medium-grained and are Ma Nsuze Group. However, recent Natal hosts numerous inliers of Archean extensively altered to upper greenschist age dating suggests a link with the crust. It is preserved in the Mesoarchean facies metamorphism and appear Usushwana Complex further north to Neoarchean granite-greenstone restricted to the undifferentiated in Swaziland. It is possible that the basement and the supracrustal volcano- basement granitoids. These dykes Usushwana Complex was the product sedimentary Pongola Supergroup are believed to be ca. 2.95 Ga and of several magmatic pulses over an which lies unconformably over it. These associated with the extension-related extended period of time, and that inliers of Archean crust host at least volcanic and sedimentary rocks of the the Hlagothi Complex followed the four distinct generations of mafic to ca. 3.07 Ga Dominion and ca. 2.98 Ga magmatic pathways of the Usushwana ultramafic dykes and sills. The dykes are Nsuze events. Complex. This signifies a possible large subvertical, and typically less than 100 The NW-trending dykes are massive igneous province in the region, and m in width. Three of these generations and medium- to coarse-grained. These a re-emergence of mafic magmatism cut the Archean crust and are absent dykes are associated with the 2.85 following the Nsuze event. These sills from the surrounding areas of Karoo Ga Usushwana event in Swaziland, are less than 200 m width and trend Supergroup sedimentary and volcanic and includes the Hlagothi Complex east-west along a major lineament in rocks, and therefore must pre-date this sills further south, which intrudes the area, dipping gently to the south. succession. These dykes include ENE- into the basal quartzite of the Nsuze The lower sills comprise meta-peridotite , NW-, NE- and N-tending dykes in Group. These sills were believed to be and meta-pyroxenite, whereas the addition to the Hlagothi Complex. upper sills comprise meta-gabbro.

Photos illustrating a NE-trending dyke in the Mvunyana granitic inlier (A), a ENE-trending dyke in the White Mfolozi inlier (B), the ultramafic section of the Hlagothi Complex with a shallow dip to the south (C), and plagioclase phenocrysts within a NE-trending dyke from the Ilangwe inlier (D)

The NE-trending dykes are porphyritic and fine- to medium-grained, many of which include phenocrysts of plagioclase feldspar (see figure). These dykes are thought to be associated with the ca. 2.65 Ga rifting related to the Ventersdorp volcano- sedimentary event and cross-cut the Pongola Supergroup. Finally, the N-trending dykes are fresh, unaltered massive and medium- to coarse-grained. These dykes are associated with the ca. 0.18 Ga Karoo magmatic event, and also cross-cut sedimentary strata of the Karoo Supergroup.

31 Preliminary geophysics and geochemistry of Muko volcano, Uganda Michael de Villers The Muko volcanic field lies at the successions consisting of northwesterly to lava bombs of size up to 600mm. northwestern end of Lake Bunyonyi, trending phyllite and quartzite. The A prominent lava flow in the centre of with the lava flow emanating from Muko volcano itself consists of a series of the valley was mapped. The lava is a volcano leading to the damming of the vents from which magma erupted as fine-grained very dark grey rock having valley and the subsequent formation gases, lava, and ejecta. The volcanic a greasy appearance with abundant of the lake (see figure). The volcano area is covered by pyroclastic rocks olivine and pyroxene discernable in the is intruded into Karagwe Ankolean of varying size from fine ash < 1mm groundmass.

Geologic map of the study area

Ground geomagnetic surveys were aeromagnetic map and the volcano was olivine formed slowly and remained as completed on the Muko Volcano. identified as a possible target for further fairly large crystals; the sudden cooling The objective of the survey was to investigation. From the geomagnetic caused the rapid crystallization of investigate the possible diamond survey two possible diatremes were the remainder of the melt into a fine economic potential of the area. identified. The survey was complicated grained matrix surrounding the olivine It was hoped that the location of by the overlying pyroclastic rocks phenocrysts. The light green olivine the diatremes could be accurately which masked the analytic signal of crystals are up to 6 mm long with an pinpointed using ground geomagnetic the magnetic survey. Processing of the average size of approximately 3 mm. survey methodology. Diamond bearing geomagnetic field data delineated two Pyroxene phenocrysts are present in kimberlite and lamproite pipes locations that may represent diatremes the lava. Petrographic and geochemical containing diamonds usually contain below pyroclastics. investigations identified the rocks from magnetite and/or ilmenite. A magnetic The lava exhibits a porphyritic texture Muko as belonging to the Kamafugite anomaly was identified by preliminary with olivine phenocrysts indicating that group. The rocks were classified as interpretation of the total field Ugandite.

Geochemical variation of MgO and SiO2 observed among the samples studied 32 STAFF NEWS

Axel Hofmann Freeman Senzani Axel Hofmann joined the Geology Freeman, an exploration Department and PPM to take up geologist involved in position as an Associate Professor. investigations in coal, His main interests revolve around petroleum, base and precious the geology of the Archaean era, metals, joined the Geology the most ancient part of Earth department and PPM. His history for which rocks as old as 4 current research interest is billion years are preserved. Under on how lime and cement the umbrella of the PPM group he production plants can be is in the process of establishing customised for use by small- a research project entitled Early scale operators in South Earth Life and Mineral Systems Africa, where large-scale Science. operations are the norm, and in Malawi, where, although there has been a long history of such small scale operations, they have been inefficient and environmentally unfriendly, especially with regard to deforestation.

POST-DOCTORAL RESEARCH ASSOCIATES From left to right, Barbara Cavalazzi, Cora Wohlgemuth-Ueberwasser, George Belyanin and Kazuyasu Shindo joined the department to further the research activities of PPM. Barbara, who received PhD from the Universitá di Modena e Reggio Emilia, Italy, has research interests primarily in the field of geomicrobiology of Precambrian hydrothermal systems and their implications for the origin of life. Cora, who received PhD from the University of Münster, Germany, has research interests on the analysis of platinum group elements (PGEs) and other trace metals in sulfides usingL A-ICP-MS facilities. George, who received PhD from the University of Johannesburg, has research interests in the field of ultrahigh-temperature metamorphism and Ar-Ar geochronology. Kazuyasu, who received PhD from the University of Tsukuba, Japan, has research interests in sulphide mineralization in mafic-ultramafic rocks, with focus on PGEs.

SUPPORT STAFF From left to right, Lisborn Mangwane (technical assistant for thin section preparation), B.T. Tshivhiahuvhi (technical assistant for rock crushing and sample preparation), and Michael Chakuparira (PPM secretary).

33 STUDENTS IN PPM – 2010

STUDENT THESIS TOPIC ADVISORS Cloete, Louis (MSc) Geochemistry of a gold-bearing K.S Viljoen, J.M. Huizenga alteration zone in the Witwatersrand succession. Crossingham, Alexandra (MSc) Modelling of diamond precipitation J.M. Huizenga, K.S. Viljoen from fluids in the Earth’s mantle. Da Silva, Richard (MSc) Characterisation of the Lucknow, N.J. Beukes Neylan and Matsap quartzites in the Koegas-Postmasburg area. Dreyer, Daphne (MSc) Geochronology and correlation of red H. van Niekerk, N.J. Beukes beds of the Paleoproterozoic Elim Group, Griqualand West. Greeff, Christiaan (MSc) Modal and cryptic variation of the M. Knoper, K.S. Viljoen, H.M. Rajesh Merensky Reef, Western Bushveld Complex. Gumsley, Ashley (MSc) Towards establishing a ‘bar code’ M. Knoper, H.M. Rajesh, and M.O. de Kock for the south-eastern terrane of the Kaapvaal Craton in northern KwaZulu- Natal,South Africa. Mabundza, Themba (MSc) Characterization of syn-Bushveld sills H.M. Rajesh, M. Knoper from the Uitkomst Complex. Mkhatshwa, Sindile (MSc) Assessment of the mineralogical K.S. Viljoen, H. Mouri variability of the UE1A and A5 reefs at Rand Uranium properties, Cooke Section, using MLA-based automated mineralogy. Mngoma, Lethuxolo (MSc) MLA-based mineralogical assessment K.S. Viljoen, H.M. Rajesh of gold and uranium mineralization at Cooke Section, Rand Uranium, Randfontein. Nel, Brian (MSc) Stratigraphy, petrography and J. Gutzmer, N.J .Beukes geochemistry of iron formations of the Koegas Subgroup of the Transvaal Supergroup Osburn, Keith (MSc) The nature and origin of the J. Gutzmer, J.M. Huizenga, C.R. McClung polymetallic Salt River massive sulphide deposit, Northern Cape Province, South Africa. Peche, Marieke (MSc) The sedimentary characteristics and N.J. Beukes, H. v Niekerk origin of Inhaca Island.

Pretorius, Donavan (MSc) Mineralogical assessment of coal K.S. Viljoen, B. Cairncross from New Vaal Colliery through the application of automated mineralogy with a view on possible beneficiation

34 Rose, Derek (MSc) The Merensky Reef at Dwarsriver M. Knoper, H.M. Rajesh , K.S. Viljoen 372 KT with reference to the mineral chemistry and the platinum-group minerals in the Merensky Reef chromitite stringers. Van der Merwe, Frits (MSc) A mineralogical investigation of K.S. Viljoen, M. Knoper Lonmin’s Akanani platinum group metal project. Van der Walt, Byron (MSc) Petrography, geochemistry and origin B. Cairncross, H.M. Rajesh of anomalous boreholes intersections in the Northern Karoo Basin. Belyanin, George (PhD) Magmatic and metamorphic D. van Reenen, H.M. Rajesh characteristics from the Limpopo Belt. Beyeme-Zogo, Jean-Clement Low grade iron ore potential of N.J. Beukes (PhD) iron formation of the Transvaal Supergroup in the Griqualand West region of the Northern Cape Province, South Africa. Chisonga, Benny (PhD) Relation of mafic dykes and sills to N.J. Beukes, H.M. Rajesh genesis of high-grade iron ore. Guy, Bradley (PhD) Massindependent sulphur isotope N.J. Beukes, J. Gutzmer fractionation in the Witwatersrand succession. Mishra, Gargi (PhD) A geometallurgical assessment of K.S. Viljoen , H. Mouri the geological and mineralogical influences on plant performance at the Nkomati Nickel Mine, Mpumalanga. Smith, Bertus (PhD) Geometallurgical characterisation of K.S. Viljoen the Merensky Reef facies at Bafokeng Rasimone Platinum Mine, South Africa. Vorster, Clarisa (PhD.) Developing ICP-MS laser ablation J. Kramers, N.J. Beukes, H. v. Niekerk zircon dating at Spectrau with application in the Cape Supergroup. Wabo, Herve (PhD) Paleomagnetism and high precision M.O. de Kock chronology of the Bushveld complex, using Bushveld related intrusions (satellites bodies, sills and dykes)

35 POST–DOCTORAL ASSOCIATES

McClung, Craig Dr. Geometallurgical assessment of K.S. Viljoen the massive sulfide deposits in the Aggeneys - Gamsberg District in the Namaqua Metamorphic Province, with an emphasis on mineralogy and location of deleterious elements.

Richards, Bryony Dr. Characterization of the Kolo K.S. Viljoen kimberlite pipe: Constraints on the composition and genesis of the diamondiferous lithospheric mantle below the eastern margin of the Kaapvaal Craton. THESES COMPLETED - 2010 LOUIS MICHIEL CLOETE (MSc) Characterization of a recently discovered zone of intense hydrothermal alteration, deformation and unusual Au mineralization at AnglogoldAshanti’s Kopanang gold mine. Supervisor: F. Viljoen PIETER HUGO FOURIE (MSc) Provenance and paleotectonic setting of the Devonian Bokkeveld Group, Cape Supergroup, South Africa. Supervisors: N.J. Beukes and U. Zimmerman S.D. OPOUBOU-LANDO (MSc) Mineralogical characterization of chromite in the UG2 Reef from Waterval Mine, Western Bushveld: Implications for minerals processing. Supervisors: J. Miller, M. Becker, F. Viljoen DANEL VAN TONDER (MSc) Petrology and geochemistry of the granitoids of the Halfway House Dome. Supervisor: H. Mouri

PUBLISHED PAPERS AUTHORS TITLE AND JOURNAL DETAILS

Abre P, Cingolani C, Zimmermann U, Provenance of Ordovician clastic sequences of the San Rafael Block (central Cairncross B, Chemale F. Argentina), with emphasis on the Ponon Trehue Formation. Gondwana Research, V. 19, pp. 275 – 290.

Bailie R, Gutzmer J, Rajesh HM Lithogeochemistry as a tracer of the tectonic setting, lateral integrity and mineralization of a highly metamorphosed Mesoproterozoic volcanic arc sequence on the eastern margin of the Namaqua Province, South Africa. Lithos, V. 119, pp. 345 - 362.

Bailie R, Gutzmer J, Strauss H, Stüeken E, Sulfur isotope characteristics of metamorphosed Zn–Cu volcanogenic McClung CR massive sulfides in the Areachap Group, Northern Cape Province, South Africa. Mineralium Deposita. V. 45, pp. 481- 496.

36 36 Belyanin GA , Rajesh HM Corundum + orthopyroxene ± spinel intergrowths in an ultrahigh- temperature Al-Mg granulite from the Southern Marginal Zone, Limpopo Belt, South Africa. American Mineralogist, V. 95, pp. 196 -199.

Blanco G, Rajesh HM, Gaucher C, Germs Reply to the comment by Sánchez Bettucci et al. on: “Provenance of the GJB, Chemale F Arroyo del Soldado Group (Ediacaran to Cambrian, Uruguay): Implications for the paleogeographic evolution of southwestern Gondwana” , V. 171, pp. 57 – 73.

Cairncross B The first book on minerals of South Africa. South African Lapidary Magazine, V. 42(1), pp. 31 - 35.

Cairncross B Gothic goethite. South African Lapidary Magazine, pp. 6 – 9.

Cairncross B, Van Niekerk H, Reinke C, Raspite from the Erongo Mountains, Namibia. Bahmann U. Rocks & Minerals, V. 85, pp. 272 - 274.

Dirks PHGM, Kibii JM, Kuhn BF, Steininger Geological Setting and Age of Australopithecus sediba from southern Africa. C, Churchill SE, Kramers JD, Pickering R, Science, V. 328, pp. 205 - 208. Farber DL, Mériaux AS, Herries AIR, King GCP, Berger LR

Ghavami-Riabi, Mouri H, Graser Applying the box plot to the recognition of footwall alteration zones related to VMS deposits in a high-grade metamorphic terrain, South Africa: a lithogeochemical exploration application. Chemie der Erde, V. 71, pp. 143 -154.

Guy B, Beukes NJ , Gutzmer J Palaoenvironmental controls on the texture and chemical composition of pyrite from non-conglomeratic sedimentary rocks of the Mesoarchean Witwatersrand Supergroup, South Africa. South African Journal of Geology, V. 113, pp. 195 – 228.

Master S, Bekker A, Hofmann A A review of the stratigraphy and geological setting of the Palaeoproterozoic Magondi Supergroup, Zimbabwe - type locality for the “Lomagundi” carbon isotope excursion. Precambrian Research, V. 182, pp. 254 - 273.

McClung CR, Gutzmer J A new chronostratigraphic paradigm for the age and tectonic history of the Beukes NJ Mesoproterozoic Bushmanland ore district, South Africa - A discussion. Economic Geology, Vol. 8, pp. 1277-1281.

Nishimiya Y, Tsunogae T, Santosh M Sapphirine corona around magnesian (XMg ~0.58) staurolite from the Palghat-Cauvery Suture Zone, southern India: Evidence for high-pressure and ultrahigh-temperature metamorphism within the Gondwana suture. Lithos, V. 114, pp. 490 - 502.

Perchuk LL, Moiseeva EI, Belyanin GA, High temperature polymetamorphism in the Central Zone of the Limpopo Van Reenen DD granulite complex (South Africa): Structural and petrologic evidence. Doklady of the Russian Academy of Science, V. 431, pp. 523 - 527.

Pickering R, Kramers J Re-appraisal of the stratigraphy and determination of new U-Pb dates for the Sterkfontein hominin site. South African.Journal of Human Evolution, V. 59, pp. 70 - 86.

Pickering R, Kramers J, Partridge T, U–Pb dating of calcite–aragonite layers in speleothems from hominin sites in Kodolanyi J, Pettke Th South Africa by MC-ICP-MS. Quaternary Geochronology, V. 5, pp. 544 - 558.

37 Praekelt HE, Germs GJB, Kennedy JH Late Ediacaran glaciation in southern Africa and its glacioeustatic record: a reply to Zimmerman’s comments on Praekelt, Germs and Kennedy (2008). South African Journal of Geology, V. 113, pp. 135 – 139.

Steinhoefe, G, Von Blanckenburg F, Deciphering formation processes of banded iron formation from the Transvaal Horn I, Konhauser KO, Beukes NJ, and Hamersley successions by combined Si and Fe isotope analyses using UV Gutzmer J femtosecond laser ablation. Geochimica et Cosmochimica Acta, V. 74, pp. 2677 - 2696.

Tolstikhin I, Kamensky I, Tarakanov S, Noble gas isotope sites and mobility in mafic rocks and olivine. Kramers J, Pekala MV, Skiba V, Gannibal M, Geochimica et Cosmochimica Acta, V. 74, pp. 1436 - 1447. Novikov D

Tsunogae T, Santosh M Sapphirine + quartz assemblage from the Southern Granulite Terrane, India: diagnostic evidence for ultrahigh-temperature metamorphism of sapphirine granulites from within the Gondwana collisional orogen. Geological Journal, V. 46, pp. 183 - 197.

Tsunogae T, Santosh M Ultrahigh-temperature metamorphism and decompression history of sapphirine granulites from Rajapalaiyam, southern India: implications for the formation of hot orogens during Gondwana assembly. Geological Magazine, V. 147, pp. 42 - 58.

Van Tonder DM, Mouri H Petrology and geochemistry of the granitoid rocks of the Johannesburg Dome, Central Kaapvaal Craton, South Africa. South African Journal of Geology, V. 113, pp. 257 - 286.

Viljoen KS , Dobbe R, Harris JW, Smit B Trace element chemistry of mineral inclusions in eclogitic diamonds from the Premier (Cullinan) and Finsch kimberlites, South Africa: Implications for the evolution of their mantle source. Lithos, V. 118, pp. 156-168.

Voegelin A, Nägler TF, Beukes N, Molybdenum isotopes in late Archean carbonate rocks: Implications for early Lacassie JP Earth oxygenation. Precambrian Research, V. 182, 70-82.

PRINTED CONFERENCE ABSTRACTS

AUTHORS TITLE AND CONFERENCE INFORMATION Beukes NJ, Gutzmer J Oxygenated oceanic environments and Mn(IV) respiration prior to the rise of atmospheric oxygen at ~2.32 Ga: Evidence from iron and manganese forma- tions. EOS (AGU Meeting of the Americas, Iguazu, Brazil, pp.231. Beukes NJ, Gutzmer J , Nel B Ce anomalies in ~2.4 Ga iron and manganese formations as proxy for early oxygenation of oceanic environments. Geochemica et Cosmochimica Acta, Goldschmidt Conference Abstracts, A85. Beukes NJ Origin of iron formation-hosted high-grade iron and manganese deposits and their paleoenvironmental significance. Abstract Volume, Iron Formation Workshop, Univ. Minnesota, Duluth . pp.45 - 51. Cairncross B “Minerals maketh man ....” so where is South Africa’s mineral heritage? South African Lapidary Magazine, pp.12. Chisonga C, Rajesh HM, New precise SHRIMP U-Pb titanite ages from the Thabazimbi sills and from Beukes NJ, Gutzmer J, dolerites at the Sishen mine. Abstract Volume, PPM Annual Colloquium, UJ Armstrong RA Hotel School, Auckland Park, pp. 6.

38 Crossingham A, A theoretical examination of diamond precipitation from fluids in the Earth’s Huizenga J-M, Viljoen KS mantle. IMA2010, 21-27 August, Budapest, Hungary. Acta Mineralogica- Petrographica Abstract Series, vol 6, p. 184. Da Silva R, Dreyer D, Vorster C Detrital zircon age populations in Gamagara/Mapedi, Lucknow and Oli- fantshoek red beds: implications for the timing of development of high-grade Sishen-type iron ore in Griqualand West. Abstract Volume, PPM Annual Col- loquium, UJ Hotel School, Auckland Park, pp. 4 - 5. GuyB A multiple-sulfur and organic carbon isotope record from the Mesoarchean Witwatersrand Supergroup, South Africa. Abstract Volume, PPM Annual Colloquium, UJ Hotel School, Auckland Park, pp.15 -16. Heimann H, Johnson CM, Beard BL, Valley Fe, C and O isotope composition of banded iron formation carbonates JW, Roden EE, Spicussa MJ, Beukes NJ demonstrate a major role for dissimilatory iron reduction in ~2, 5 Ga marine environments. Earth and Planetary Science Letters, V. 294, pp. 8 -18. Johnson CM, Heimann A , Beard BL, Valley Fe, C and O isotope compositions of banded iron formation carbonates JW, Roden EE, Spicuzza MJ, Beukes NJ demonstrate the role of bacterial dissimilatory iron reduction in ~2.5 B.Y. old marine environments. Abstracts, NE-SE GSA Regional Meeting, pp. 56. Kruger F, Beukes NJ Iron formations and magnetite ore bodies of the Aggeneys area. Abstract Volume, PPM Annual Colloquium, UJ Hotel School, Auckland Park. pp. 3 - 4. McClung CR, Viljoen F Mineralogical Investigation of the Aggeneys-Gamsberg BHT District, South Africa: Implications for Classification of a Classical Broken Hill-type District: SEG 2010 Conference, 2-5 October 2010, Keystone, USA, D-11, 3 pp. McClung CR, Viljoen KS Ore mineralogy of the world-class Gamsberg zinc sulfide deposit, South Africa: Geological Society of America Meeting 31 October-3 November 2010, Denver, Colorado, USA. Geological Society of America Abstracts with Pro- grams, vol 42, No. 5, p. 535. McClung CR, Viljoen F Mineralogical assessment of sphalerites from the Gamsberg deposit, South Africa: the manganses conundrum. Proceedings of Processing of Zinc Ores and Concentrates 2010, Cape Town, South Africa, 13 November 2010, p. 1-3 Nel , Beukes NJ Geochemistry of ~2.4 Ga Koegas and Duitschland iron formations and impli- cations for oceanic environments at the time. Abstract Volume, PPM Annual Colloquium, UJ Hotel School, Auckland Park. pp. 3. Moore M, Shaikhaidarov R, Petrashov V, Probing inclusions in diamonds with fine beams of synchrotron X rays. 26th Viljoen F European Crystallographic Meeting, ECM 26, Darmstadt, Germany. Acta Cryst. A66, s303.

39 Richards BG, McClung CR, Viljoen KS Characterization of the Kolo Kimberlite Pipe: Constraints on the composition and genesis of the diamondiferous lithospheric mantle below the eastern margin of the Kaapvaal Craton. Geological Society of America Meeting 31 October-3 November 2010, Denver, Colorado, USA. Geological Society of America Abstracts with Programs, vol 42, No. 5, p. 579. Rose DH, Knoper MK, Rajesh HM, Viljoen KS In-situ, MLA-based examination of Platinum Group Minerals associated with chromitite stringers in the Merensky Reef of the Eastern Bushveld Complex, South Africa. IMA2010, 21-27 August, Budapest, Hungary. Acta Mineralogica- Petrographica Abstract Series, vol 6, p. 272. Smith AJB, Beukes NJ, Gutzmer J, Co- Evidence for dissimilatory manganese reduction and availability of free chrane JM molecular oxygen during deposition of Mesoarchean Witwatersrand-Mozaan strata. Geochemica et Cosmochimica Acta, Goldschmidt Conference Abstracts, pp. A973. Smith AJB, Viljoen KS, Schouwstra R, Roberts The geometallurgical characterisation of different Merensky Reef facies in the J, Schalkwyk C, Gutzmer J western limb of the Bushveld Complex, South Africa. IMA2010, 21-27 August, Budapest, Hungary. Acta Mineralogica-Petrographica Abstract Series, vol 6, p. 278. Smith AJB, Viljoen KS, Schouwstra R, Roberts Geological variations in the Merensky Reef at Bafokeng Rasimone platinum J, Schalkwyk C, Gutzmer J mine and it’s influence on milling and flotation performance. Proceedings of Process Mineralogy ’10, Cape Town, South Africa, November 10-12, 2010. www.min-eng.com. Unpaginated. Van der Merwe F, Viljoen KS, Knoper MW An in-situ, MLA-based mineralogical examination of the Akanani Platinum Group Metal Project, Bushveld Complex, South Africa. IMA2010, 21-27 August, Budapest, Hungary. Acta Mineralogica-Petrographica Abstract Series, vol 6, p. 273 Viljoen KS, Harris JW, Ivanic T, Richardson Trace element geochemistry and Ni thermometry of garnet inclusions in SH, Whitehead K peridotitic diamonds from Premier and Finsch, South Africa: implications for diamond formation. IMA2010, 21-27 August, Budapest, Hungary. Acta Mineral- ogica-Petrographica Abstract Series, vol 6, p. 187.

CONFERENCE PRESENTATIONS

NAME TITLE OF PAPER CONFERENCE/PLACE OF MEETING Beukes NJ The origin of high-grade BIF-hosted Geology Seminar Series iron ore. University of Manitoba, Canada, 12 March. Beukes NJ Classification and geology of iron ore Mike Porter Iron Ore Workshop, Sandton, South deposits of South Africa. Africa, 19 April. Beukes NJ Origin of iron formation-hosted high- Iron Formation Workshop, University of grade iron and manganese deposits Minnesota, Duluth, 12 October. and their paleoenvironmental significance. Beukes NJ Nature and paleoenvironmental Workshop on iron and manganese formations. significance of Precambrian Federal University of Ceara (UFC), Fortaleza, manganese deposits. Brazil, 23 November. Beukes NJ Iron formation depositional systems Workshop on iron and manganese formations. and their paleoenvironmental Federal University of Ceara (UFC), Fortaleza, significance. Brazil, 24 November.

40 Beukes NJ Origin of high-grade iron ore deposits Workshop on iron and manganese formations. with special reference to Bif-hosted Federal University of Ceara (UFC), Fortaleza, deposits. Brazil, 24 November. Beukes NJ, Gutzmer J, Nel BP Ce anomalies in ~2.4 Ga iron and Goldschmidt Conference, Knoxville, USA, 17 manganese formations as proxy June. for early oxygenation of oceanic environments. Beukes NJ, Gutzmer J Oxygenated oceanic environments AGU Meeting of the Americas, Iguazu, Brazil, 12 and Mn(IV) respiration prior to the rise August. of atmospheric oxygen at ~2.32 Ga: Evidence from Iron and manganese formations. Cairncross B Can legislation protect rare geological 6th International Geoscience Education specimens - a case study from South Conference, University of the Witwatersrand, 29 Africa August 3 September. Cairncross B The Johannesburg Geological 6th International Geoscience Education Museum - an earth science education Conference, University of the Witwatersrand, 29 extravaganza August - 3 September. Cairncross B Exotic micro-minerals from Aris, 3rd Southern African Mineral Symposium, Council Namibia. for Geoscience, Pretoria, 20 November. Cairncross B Micro-minerals from the Bushveld 3rd Southern African Mineral Symposium, Council Complex, South Africa. for Geoscience, Pretoria, 20 November. Cairncross B The mineral collection of Bruce 3rd Southern African Mineral Symposium, Council Cairncross. for Geoscience, Pretoria, 20 November. Cairncross B Should legislation protect South PPM Annual Colloquium, UJ Hotel School, Africa’s rare geological specimens? 18 November. Cairncross B The National Heritage Resource Act PPM Annual Colloquium, UJ Hotel School, 18 and rare geological specimens. November. Cairncross B World famous South African mineral MINSA (Mineralogical Society of South Africa), localities. AGM, UJ, 5 August. Cairncross B The Tucson Gem and Mineral Show - a Witwatersrand Gem & Mineral Club monthly 12-year retrospective. meeting, UJ, 27 January. Cairncross B Photographing minerals Witwatersrand Gem & Mineral Club monthly meeting, UJ, 21 March.

41 Cairncross B The Messina copper mines: before, Witwatersrand Gem & Mineral Club monthly during and after. meeting, UJ, 26 May. Cairncross B Who is responsible for South Africa’s Witwatersrand Gem & Mineral Club monthly mineral heritage? meeting, UJ, 28 July. Chisonga B, Rajesh HM New precise SHRIMP U-Pb titanite PPM Annual Colloquium, UJ Hotel School, ages from the Thabazimbi sills and Bunting Road Campus, 18 November. from dolerites at the Sishen mine. Crossingham A, Huizenga JM, A theoretical examination of diamond 20th General Meeting of the International Viljoen KS precipitation from fluids in the Earth’s Mineralogical Association, Budapest, Hungary, mantle. 21-27 August. Da Silva R, Dreyer D, Vorster C Detrital zircon age populations in PPM Annual Colloquium, UJ Hotel School, Gamagara/Mapedi, Lucknow and Bunting Road Campus, 18 November. Volop red beds: implications for the timing of development of high-grade Sishen-type iron ore in Griqualand West. Rose D, Knoper MW, Rajesh HM, In-situ, MLA-based examination 20th General Meeting of the International Viljoen KS of platinum group minerals Mineralogical Association, Budapest, Hungary, associated with chromitite stringers 21-27 August. in the Merensky Reef of the eastern Bushveld Complex, South Africa. Guy B Mass-independent sulfer isotope PPM Annual Colloquium, UJ Hotel School, fractionation in the Witwatersrand Bunting Road Campus, 18 November. succession Gutzmer J, Beukes NJ Iron ore resources of South Africa. PDAC Conference, Toronto, Canada, 5-11 March. Knoper MW Re-evaluating the provenance of gold Society of Economic Geologists SEG Conference, in the Witwatersrand basin, South Keystone, USA, 2 - 5 October. Africa using shale geochemistry. Knoper MW The Mesoproterozoic Geological Society of America Annual Meeting, Steenkampskraal rare-earth element Denver, USA, 31 October - 3 November. deposit in Namaqualand, South Africa Knoper MW Episodic mafic magmatism during the Geological Society of America Annual Meeting, Mesoarchean to Paleoproterozoic on Denver, USA, 31 October - 3 November. the Kaapvaal Craton: implications for cratonic reconstructions. Kramers JD The ancient gneiss terrain in the Field workshop on early crustal evolution of the context of global crustal evolution southeastern Kaapvaal craton in South Africa and models. Swaziland, Manzini, Swaziland, 17-23 May. Kramers JD An update on the Limpopo Belt. Centennial Conference, Geological Survey of Zimbabwe, Harare, Zimbabwe, 21 October. Kramers JD Constraints on models for the Centennial Conference Geological Survey of formation of the Limpopo Belt, from Zimbabwe, Harare, Zimbabwe, 21 October. Nd and Hf isotope systematics.

42 McClung C, Viljoen F A detailed mineralogical investigation SEG conference, 2-5 October, Keystone, USA. of the of the Aggeneys-Gamsberg BHT District, South Africa: Implications for classification of a classical Broken Hill-type district McClung C, Viljoen KS Ore mineralogy of the world-class Geological Society of America Meeting, Gumbserg zinc sulfide deposit, South 31 October - 3 November 2010, Denver, Africa Colorado, USA. Moore M, Shaikhaidarov K, Probing inclusions in diamonds with 26th European Crystallographic Meeting, Petrashow V, Viljoen F fine beams of synchrotron X rays. Darmstadt, Germany, 29 August - 2 September. Nel B, Beukes NJ Geochemistry of ~2.4 Ga Koegas iron PPM Annual Colloquium, UJ Hotel School, formation and implications for oceanic Bunting Road Campus, 18 November. environments at the time. Richards BG, McClung CR, Characterization of the Kolo Geological Society of America Annual Viljoen KS Kimberlite Pipe: Constraints on the conference, Denver, Colorado, 31 October - composition and genesis of the 11 November. diamondiferous lithospheric mantle below the eastern margin of the Kaapvaal Craton. Smith AJB, Viljoen KS, Geological variations in the Merensky Process Mineralogy, Cape Town, 10 -12 Schouwstra R, Roberts J, Reef at Bafokeng Rasimone Platinum November. Schalkwyk C, Gutzmer J Mine (BRPM) and its influence on milling and flotation performance. Smith AJB, Viljoen KS, The geometallurgical characterization 20th General Meeting of the International Schouwstra R, Roberts J, of different Merensky Reef facies in Mineralogical Association, Budapest, Hungary, Schalkwyk C, Gutzmer J the western limb of the Bushveld 21 - 27 August. Complex, South Africa. Smith AJB, Beukes NJ, Gutzmer Evidence for dissimilatory manganese Goldschmidt Conference, Knoxville, USA, J, Cochrane JM reduction and availability of free 18 June. molecular oxygen during deposition of Mesoarchean Witwatersrand- Mozaan strata. Van der Merwe F, Viljoen KS, An in-situ, MLA-based mineralogical 20th General Meeting of the International Knoper MW examination of the Akanani platinum Mineralogical Association, Budapest, Hungary, group metal project, Bushveld 21-27 August. Complex, South Africa. Viljoen KS, Harris JW, Ivanic T, Trace element geochemistry and Ni 20th General Meeting of the International Richardson SH, Whitehead K thermometry of garnet inclusions in Mineralogical Association, Budapest, Hungary, peridotitic diamonds from Premier 21 -27 August. and Finsch, South Africa: implications for diamond formation.

43 University of Johannesburg Department of Geology PALEOPROTEROZOIC MINERALIZATION RESEARCH GROUP Venue The University of Johannesburg, Auckland Park Kingsway Campus, Main Building, B Les 103, Kingsway, Auckland Park Date Thursday, 3 November 2011 Time 13h00 – 20h00 The Paleoproterozoic Mineralization Research Group (PPM) in the Department of Geology at the University of Johannesburg, Department of Geology was formed in 1997. At present (2011), research involves thirteen academic staff members, four post-doctoral researchers, eight PhD and seventeen MSc students. The PPM research group receives funding from South Africa’s mineral industry, the National Research Foundation and Research Grants provided by the University of Johannesburg. THE OBJECTIVES OF PPM INCLUDE: • To study and model the relationship between environmental change and styles of mineralization in the Precambrian, with a specific focus on the Paleoproterozoic Era. • To apply the knowledge for evaluating the mineral exploration and beneficiation potential of that era (1.6 - 2.5 billion years ago) on a global scale. • To ensure a competitive edge for industrial partners in global mineral exploration and acquisition markets by studying the temporal and spatial distribution, composition, and origin of mineral deposits, on local and regional scale. • To train postgraduate students in the fields of especially, but not exclusively, Economic Geology and Geometallurgy. PURPOSE OF THE COLLOQUIUM The research colloquium is aimed to present major findings of different research focus areas of PPM to professionals from the industrial and academic environment as well ANNUAL RESEARCH

COLLOQUIUM as current and prospective post-graduate students. Attendance is free of charge but booking is essential. More information can be obtained from Michael Chakuparira (email: [email protected]; tel 011-559-4715) 44 PPM ANNUAL RESEARCH COLLOQUIUM PROVISIONAL PROGRAMME Date: Thursday, 3 November 2011 Place: University of Johannesburg, Kingsway Campus, Building B Les 103 Time: 13h00-20h00

13.00 - 13.30 Registration, Tea & Coffee 13.30 - 13.35 Opening Remarks Fanus Viljoen Geometallurgical characteristics of the Merensky 13.35 - 13.55 Reef, Bushveld Complex Bertus Smith Post-Permian diatreme activity in the 13.55 - 14.15 northeastern Karoo basin Byron van der Walt Assessment of the mineralogy and Au deportment of reefs at Cooke Section, Rand Sindile Mkhatshwa, Lethuxlo 14.15 - 14.35 Uranium properties Mngoma Geochronology and correlation of Paleoproterozoic red beds of the Elim Group in 14.35 - 14.55 Griqualand West, Northern Cape Province Daphne Dryer, Clarisa Vorster Fluorite mineralization associated with lujavrite from the Mesoproterozoic Pilanesberg Alkaline 14.55 - 15.15 Complex Sara Turnbull Structural setting of the Steenkampskraal 15.15 - 15.35 monazite REE ore body Mike Knoper 15.35 - 15.55 Tea Multiple sulfur isotope signatures of diagenetic pyrite nodules in quartz pebble conglomerates of the Witwatersrand Supergroup and 15.55 - 16.15 Ventersdorp Contact Reef Bradley Guy Nontraditional stable isotope in Archean 16.15 - 16.35 geology Axel Hofmann 16.35 - 16.55 The Noble gas lab: Developments and projects Jan Kramers Spodumene-bearing pegmatites from the Greenlands Formation, Vredefort Impact 16.55 - 17.15 Structure Brandon Zacharopoulos Paleomagnetic and geochemical characterization of post-Transvaal sills and dykes 17.15 - 17.35 in the eastern Kaapvaal Craton Herve Wabo Paleogeographic position of India during the break-up of the Mesoproterozoic supercontinent 17.35 - 17.55 Nuna Michiel de Kock 17.55 - 18.05 Concluding Remarks Nic Beukes 18.05 - Wine and Snacks

45 SPECTRAU SPECTRAU, the Central Analyrtical Facility of the Faculty of Science at UJ, was established in 1999 as a one-stop state-of-the-art analytical facility that is managed and staffed to ensure an accessible analytical service not only for UJ staff and students but also for outside clients. SPECTRAU operates 24hrs per day and offers wide and comprehensive solutions for a broad range of applications utilizing modern high-tech MLA Lab equipment that include a PANalytical X’Pert Pro XRD, PANalytical Magix Pro XRF, a Jeol 733 microprobe, a Jeol 5600 SEM, two ThermoFisher X- SeriesII ICP-MS’s, a Spectro ARCOS ICP-OES, a SHIMADZU QP2010 GC- MS, a Metter Toledo DSC 822e DSC, a Varian Unity Inova NMR system, a ThermoFisher DFS (High resolution GC-MS), a ABI 3130xl genetic znalyser, a BD FACSAria flow cytometer as well as Zeiss Axioplan 2 compound and Zeiss Discovery stereo microscopes. EPMA Lab SPECIALIZED GEOSCIENCE APPLICATIONS AT SPECTRAU Apart from the more general instrumentation at Spectrau mentioned above, it also houses five facilities geared rather specifically to Geoscience applications and the needs of PPM. Two of these represent unique Ar/Ar Lab African facilities with another a unique African university-housed facility. They are: • A MAP-215 noble gas mass spectrometer with both infrared and ultraviolet lasers. This instrument will be utilized for Ar-Ar geochronology as well as research into other isotopic systems. It is a unique African facility. • A fully functional paleomagnetic laboratory, unique in Africa, which has recently been upgraded with a fully automated snake chain sample ICP-MS Laser Ablation Lab changing system and a state of the art SQUID magnetometer. This will allow for rapid and much more efficient measurement of samples for paleomagnetic studies. • Two MLA’s (Mineral Liberation Analysers), the one being an older generation FEI XL-40 and the other a state of the art FEI 600F field emission system. These instruments are extensively used in research in the field of geometallurgy and are the only ones housed at a University in Africa. • A New-Wave UP-213 Nd:YAG laser permanently connected to the one ThermoFisher X-SeriesII ICP-MS which is dedicated for laser ablation studies, especially for the age determination of detrital zircons. • A new Cameca SX-100 electron microprobe equipped with 3 wavelength dispersive detectors and one energy dispersive detector making it ideal for in-situ chemical analysis of minerals. For further information and cost of services please contact: Dr Willie Oldewage, Tel: 011 559 2274, Fax: 011 559 3361 Paleomag Lab Email: [email protected] 46