VOLUME 43 . DECEMBER 2015

INSIDE:

Airborne geochemical mapping in Namaqualand I 1Ndivhuwo Cecilia MukosiRobert NetshitungulwanaSibongiseni Hlatshwayo

Seismotectonic map of Africa I 3Vunganai Midzi

Preliminary CO2 emissions monitoring on natural CO2 releases in KwaZulu-Natal I 4Nigel Hicks

Participation in the NAM S&T Centre and DST Training Fellowship I 6Marcelene Voigt

42nd International Association of Hydrogeologists Congress I 7Kate Robey

Council for Geoscience Conference 2016 I 8

Airborne geochemical mapping in NamaqualandThe Namaqualand geochemical mapping project is a continuation of the Mid-Term Expenditure Framework (MTEF) project mandated by National Treasury through the Department of Mineral Resources (DMR) for mineral target generation in South Africa. The objectives of the Namaqualand geochemical mapping project are:

(a) To stimulate exploration and mining investment in the mineral and energy sectors by generating mineral potential targets.

(b) To aid in the acquisition of exploration geochemistry data for the generation of mineral potential target areas and

the establishment of an updated geochemical database, as this will assist in providing a variety of geoscientific solutions.

The study area is situated in the Succulent Karoo biome, identified as one of the world’s 34 biodiversity hot spots containing about 3 000 species, of which 1 500 are endemic. The region is generally semi-arid to arid and largely flat, with few mountainous areas. The Namaqua-Natal Province is considered to embrace the igneous and metamorphic rocks formed during the Namaqua Orogeny at 1 200 to 1 000 Ma. The dominant Bushmanland Terrane consists of granitic gneisses, amphibolite

Namaqualand team at the refuelling spot with the ZS-RZJ helicopter. Top left: Frans, Lerato, Donald, Tendani and Zweli. Bottom left: Eliah, Azwi, Lebo, John, Dattner, Rudzani, Mzoli and Ndivhuwo.

I GeoClips2

granitoid related vein- and greisen-type wolframite-scheelite-cassiterite mineralisation occurs in shear fractures adjacent to intrusive granitoids and feldspar, muscovite, beryl, spodumen, fluorite and columbite mineralisation in pegmatoids in the Kakamas and

to granulite grade supracrustal rocks and granitoids. The major mineral deposits are the SEDEX-type Pb-Cu-Zn deposits which include the Black Mountain and Gamsberg deposits at Aggeneys. The Okiep Copper District contains numerous intrusions of the Koperberg Suite, with many of these bodies hosting copper sulphide mineralisation. The

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Garies

Askham

Prieska

Kuruman

Kakamas

Hotazel

Aggenys

Richmond

Pofadder

Kenhardt

Hopetown

CalviniaWilliston

Steinkopf

KimberleyGoodhouse

Colesberg

Carnarvon

Bucklands

BritstownBrandvlei

Windsorton

Vioolsdrif

Sutherland

Hutchinson

Hartswater

Griquatown

Fraserburg

Vanderkloof

Van Zylsrus

RiemvasmaakPostmasburg

Barkly West

Van Wyksvlei

Port Nolloth Niekerkshoop

Groblershoop

Alexander Bay

Loeriesfontein

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28°0'0"E

24°0'0"E

24°0'0"E

20°0'0"E

20°0'0"E

16°0'0"E

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TOPOGRAPHICAL DATA

" CITY/TOWN

CO ORDINATE LINE

PROVINCIAL BOUNDARY

Map Compiled by M Matshivha October 2015

Assisted by the Personnel ofthe Council for Geoscience

0 50 100 150 20025Kilometres

1:1 800 000Ê Datum: WGS- 1984

N O R T H E R N C A P E P R O V I N C E

F R E E S T A T EP R O V I N C E

W E S T E R N C A P E P R O V I N C E

NAMAQUA STUDY AREA

N O R T H W E S T P R O V I N C E

KHEIS TERRAINE

KAAPVAL CRATONBOUNDARY

Beaufort Group

Ecca Group

Dwyka Group

Cape Supergroup

Vanrhynsdorp and Nama Groups

Gariep Supergroup

Namaqua Metamorphic Province

Transvaal Supergroup

Venterdorp Supergroup

KarooSupergroup

Dolerite(intrusive)

Olifantshoek Supergroup

Cenezoic

Kalahari Group

Geological Legend (Simplified)COMMODITY SYMBOLSGold

Diamond (alluvial) Beryllium Bismuth Copper Iron Lead Lithium Nickel Manganese Molybdenum Rare Earths

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Tantalum/Niobium !.

Diamond (in kimberlite) XY

Tin Titanium Thorium Tungsten UraniumZinc

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!(POFADDER2918AA 2919AB 2919BB

2919BA2919AA2918BB2918BA2918AB

2918CA 2919CB2918DA 2919DA 2919DB2919CA2918DB

2918AC 2919AD

2918CB

2919BD2919BC2918BD 2919AC2918BC2918AD

2918CC 2919CD2918CD 2919DD2919DC2919CC2918DD2918DC

¯

0 30 60 90 12015Kilometers

NAMAQUALAND PROJECT AIRBORNE REGIONAL SOILSAMPLING PROGRESS MTEF ST2013-1163

Legend2918 Completed maps

2919 Completed maps

Planned maps for 2015/16

Mineral occurrences in the study area (western block outlined in blue).

Bushmanland terranes. Palaeochannel or surficial uranium mineralisation similar to the palaeochannel uranium deposits of Namibia also occurs in the area. The Areachap and Kakamas terranes contain volcanic hosted Zn-Cu deposits.

The initial geochemical mapping programme commenced in the early 1970s and was standardised after orientation studies were conducted in 1978. The current sample density of the national regional geochemical mapping programme in South Africa is one sample per km2 of 5 kg weight. Each 5 kg sample is taken from the top 20 cm or A-horizon. The samples are then transported from the field to the CGS laboratory, where they are prepared and dry sieved to -75 microns for analysis. The samples will be analysed for more than 40 element suites using the Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) analytical method.

The reconnaissance project phase commenced in March 2014 and was followed by helicopter soil sampling. The reconnaissance phase involved robust communication between different stakeholders in the area including farmer associations, given that 80 % of the area is largely taken up by stock farming. In the past seven months, the Council for Geoscience has managed to map 75 % of the study area, which translates to the completion of 25 maps, with over 16 878 soil samples having been collected. Currently, seven maps are left to complete the entire project.

Soil sampling using a helicopter comes with its own challenges. These include bad weather conditions such as rain, strong winds, fog or mist which lead to operational delays. Technical issues include difficulties such as the main and tail rotor blade tape of the helicopter becoming worn out, and scheduled and unscheduled maintenance. During the period of delay, which may last from two to three days, the team focusses on field excursions and team building activities. Since the beginning of the project, the field team has participated in (a) a Pofadder Shear Zone field excursion to Pella, (b) a visit to the abandoned mine in Okiep (one of the first copper deposits

Namaqualand in spring.

Helicopter soil sampler in action.

The Namaqua team playing soccer on the now dry sandy part of the Orange River as

part of the team building activities.

The red and purple maps have been completed. The green map is currently being

sampled.

GeoClips I 3Geoclips - Volume 43 - December 2015

For more information contact:Ndivhuwo Cecilia MukosiMapping Geosciences+27 (0)15 295 3471cmukosi@geoscience.org.za

Robert Netshitungulwana (Project Task Leader)Economic Geology+27 (0)12 841 1380robertn@geoscience.org.za

Sibongiseni Hlatshwayo (Assistant Task Leader)Economic Geology+27(0)12 841 1503shlwatswayo@geoscience.org.za

to be mined in South Africa and ranked the richest copper mine in the world in the 1870s), (c) a visit to the small mining town of Concordia, approximately 10 km north of Okiep, and (d) a CGS Heritage Fun Walk, which took place on Heritage Day. The participants walked from Bergsig to Okiep and back, a distance of some 18 km!

The project team wishes to thank the DMR for financial support and BAC Helicopters for their services. The Namaqualand team consists of: Project Manager — Dr Alazar Billay; Project Task Leader — Mr R. Netshitungulwana; Field Supervisor(s) — Mr S. Hlatshwayo, Mr A.E. Mulovhedzi, Mr T. Ntikang and Ms N.C. Mukosi; Geologists — The late Ms L. Ramalata, Mr M. Breakfast, Mr R. Lusunzi, Ms M. Modiba, Mr T. Mofokeng, Ms P. Shingage, Mr R. Chauke, Mr M. Malatji, Mr B. Hanise and Mr M. Shai; Technical Officers — Mr J. Radebe, Mr J. Mokoatedi, Mr I. Phahlane, Mr S. Zondi, Mr M. Ramoshaba, Mr M. Mudau, Ms L. Madiba, Mr D. Nxumalo, Mr D. Mathabatha, Mr Z. Bubani, Mr T. Thiba, Ms L. Ramaremela, Ms M. Ramuatho, Mr B. Makofane, Mr I. Chuene, Mr R. Ngobeni and Mr S. Cele. Special thanks also go to the sample transportation team led by Mr D. Makgate and to the senior level team who assisted towards the success of the sampling phase of the project — Dr S. Foya, Mr J.H. Elsenbroek, Mr M. Bensid and Mr J. van der Merwe.

Seismotectonic regions in Africa are poorly understood in terms of current faulting activities, crustal deformation and geodynamic causes. The most well known of these regions are the North Africa Thrust and Fold Belt and the East African Rift System, where large earthquakes have been experienced. However, other regions such as the Cameroon Volcanic Line and the Congo Basin in Central Africa and the West African and Southern African plateaus are also seismically active. Major active faults that generate destructive earthquakes rank amongst the most important geological and geophysical hazards on the continent.

The development of a thematic map with the identification and characterisation of seismically active zones constitutes the framework for seismic hazard assessment and the mitigation of seismic catastrophes. At its meeting in Algiers in May 2011, the Organisation of African Geological Surveys (OAGS) requested the preparation of a seismotectonic map of the African continent and the seismic hazard and risk implications. A working group consisting of Mustapha Meghraoui (Coordinator) (EOST – IPG Strasbourg); Paulina Amponsah (GAEC, Accra); Abdelhakim Ayadi (CRAAG, Algiers); Atalay Ayele (University of Addis Ababa); Bekoa Ateba (IRGM, Yaoundé); Abdunnur Bensuleman (Tripoli University); Damien Delvaux (MRAC, Tervuren); Mohamed El Gabry (NRIAG, Cairo); Rui-Manuel Fernandes (UBI/IDL, Portugal); Vunganai Midzi and Magda Roos (CGS, Pretoria) and Youssef Timoulali (Mohamed V University, Rabat) was formed to address these issues in the framework of IGC Project 601, Seismotectonics and Seismic Hazards in Africa, of UNESCO-IUGS, funded by the Swedish International Development Agency and UNESCO Nairobi for a period of four years (2011–2014), extended to 2016. Apart from the Working Group, many other geoscientists (mostly from African academic and research institutions) assisted in the preparation of the map by contributing data and conducting several

scientific projects in earthquake geology, seismology, seismotectonics, geodesy and geophysics in Africa.

The seismotectonic mapA major objective linked to the seismotectonic map is the constitution of a database that includes historical and instrumental seismicity, active tectonics, stress tensor distribution, earthquake geology, palaeoseismology, earthquake geodesy and present-day velocity fields (GNSS), crustal structure and seismic tomography, gravity, magnetic and structural segmentation, volcanic fields, rifting processes and geodynamic evolution. Guidelines for the preparation of the seismotectonic map and related data analysis were used in order to obtain homogeneous data and results across the continent. An important step is the harmonisation of the database (e.g. earthquake intensities, magnitudes, fault parameters, etc.) at a local, regional and continental level.

Based on local and regional studies, the seismotectonic map was constructed in order to address the following activities: 1) Building a homogeneous database of seismic parameters, 2) Preparing a database of neotectonic structures with Quaternary faulting, 3) Improving the seismotectonic database in regional gaps, 4) Building a GIS interface for the geological and geophysical database.

Strain field and geodetic networkFrom a tectonic point of view, the African continent is divided into two main plates, Nubia and Somalia, separated by the two rift branches of the East African Rift, with two to three smaller tectonic blocks in between. However, uncertainty exists concerning the number and distribution of the tectonic blocks along the East African Rift region. This complex subplate distribution is in the process of being better constrained with the installation of an increasing number of permanent GNSS stations in Africa. The seismotectonic map presents the current status of the strain distribution using the present-day GNSS velocity field of Africa, with respect to the latest

Seismotectonic map of Africa

I GeoClips4

global reference frame ITRF2008. The existing number of sites (approximately 100 permanent GNSS stations) and a threshold value of 2.5 years of data permit the computation of a velocity field that can be used to obtain the general pattern of the current strain field for Africa.

Database and GISA well-structured seamless database of a collection of seismic (instrumental and historical), tectonic, geodesy, remote sensing and geophysical data was created. The ESRI product, ArcGIS Suite, was used to prepare, manage, analyse and map the data. Although access is currently restricted to the

project team, the database is already interfaced with internet applications, mainly to keep the team updated on the status of the database.

ConclusionThe seismotectonic map is based on a completed re-appraised historical and instrumental seismicity catalogue with harmonisation and homogenisation of earthquake parameters. The database includes information on the coseismic and Quaternary faulting that reveal the complex nature of the active tectonics in Africa. The map also benefits from previous work on local and regional seismotectonic maps that needed to be integrated with the lithospheric

Spreading ridge systems of the African plate and the Nubia–Eurasia complex convergence system.Seismotectonic map of Africa.

and upper mantle structures from tomographic anisotropy and gravity anomalies into a continental framework.

The synthesis of earthquake studies with the analysis of active deformation presented along with the seismotectonic map serves as a basis for seismic hazard calculations and the reduction of seismic risks on the continent.

Anthropogenic carbon dioxide (CO2) is the largest contributor of greenhouse gas emissions on the planet. Although a number of clean-energy technologies exist and their global input to the energy sector is increasing, the continued exploitation of fossil fuels is not showing a decline. Therefore, clean-coal

For more information contact:Vunganai MidziGeophysics+27 (0)12 841 1492vmidzi@geoscience.org.za

Preliminary CO2 emissions monitoring on natural CO2 releases in KwaZulu-Natal

technologies such as Carbon dioxide Capture and Storage (CCS) are vital to mitigating global climate change. The Council for Geoscience, in collaboration with the South African Centre for Carbon Capture and Storage (SACCCS), has been at the forefront of CCS innovation in South Africa since 2010, and is

currently embarking on a new ambitious project to monitor naturally occurring CO2 emissions identified at four sites in southern KwaZulu-Natal. The project, a collaboration between the CGS, SACCCS and international organisations such as the British Geological Survey, UK CCS Research Centre, Scottish

GeoClips I 5Geoclips - Volume 43 - December 2015

assistance from Mzikayise Nkwane of the University of KwaZulu-Natal in an attempt to identify any variations in the water quality from the CO2 gas borehole and a second borehole drilled ~180 m west, which did not have detectable CO2 gas concentrations. The field measurements of the two boreholes did indeed show a noticeable difference, with the CO2 borehole having a lower pH and higher total dissolved solids (TDS) content compared to the CO2-absent borehole. The dissolved oxygen (DO) concentrations also showed a significant difference, with the CO2-absent borehole measuring approximately 3 mg/ℓ DO compared to the 0.7 mg/ℓ measured in the CO2-rich borehole. Groundwater samples for composition and stable isotope analyses were collected from each of the boreholes for further research to better understand the observed differences.

A number of travertine (calcium carbonate precipitate) cones occur along

the banks of the Umtamvuna River in KwaZulu-Natal and the Eastern Cape. The site is the southernmost known CO2 emissions site along the Bongwana fault, with four cones developed on top of large mounds of travertine of about 50–100 m in diameter on either side of the river. The cones on the northern bank are by far the largest (~15 m diameter), but the smaller cones on the southern bank are the most active. Both issue CO2 gas and water, with the larger cone being steep sided ~1 m in diameter and 80 cm high. Water sampling of the three travertine cones gave similar pH values, but TDS and DO values varied per travertine cone site. Soil gas sampling along the alluvial terrace on the northern bank of the river defined a sharp spike in CO2 concentrations and flux in the soil across the fault trace, with concentrations attaining a maximum of 28 % CO2. CO2 gas samples were taken from all active cones for stable isotope and noble gas analyses at the University of Edinburgh.

a) CGS and international scientists discussing the local geology. b) Groundwater sampling on Baker Farm. c) Soil gas concentration sampling with BGS scientists. d) Soil flux

measurements on Baker Farm. e) CO2 gas sampling at Umtamvuna River with SACCCS scientists.

Carbon Capture and Storage, and the Universities of Edinburgh, Strathclyde and Aberdeen, aims to both build CO2 monitoring capacity in South Africa as well as to establish concepts in the lead-up to the proposed Pilot CO2 Storage Project which is scheduled to begin in 2017.

Although anthropogenic CO2 is defined as a greenhouse gas, naturally occurring CO2 is an essential component of life, with the global carbon cycle comprising a complex array of geological, oceanic and biological processes that constantly recycle CO2 around the globe. Natural occurrences of CO2 emanating from the subsurface are common, especially in volcanic regions such as Italy; however, CO2 seeps in tectonically stable regions such as South Africa are less common. The natural CO2 release sites at the Umtamvuna River, Mjaja District, Bongwana Siding and Baker Farm therefore represent perfect natural analogues in which soil gas, atmospheric and geological monitoring can be undertaken.

Work focussed on Baker Farm where a water borehole some 60 m deep had been drilled for water supply purposes, but unfortunately the hole only produced groundwater rich in CO2 with CO2 gas issuing from the hole. This site served as the perfect base for the preliminary monitoring of soil gas concentrations and soil gas flux, with two phases of sampling undertaken over a period of four days. The initial sampling phase was undertaken with the borehole being open to the atmosphere, while the second phase of gas sampling was undertaken with the borehole capped. High CO2 values in the soil gas (50 % uncapped; 80 % capped) and high CO2 flux (422 g/m2/day) were confined to a narrow ~30 m wide, north-trending zone above a blind fault with values away from the fault returning background CO2 readings. Although the fault is now blind owing to current agricultural activities, historical maps have been used to identify the proposed fault trace which correlates well with elevated CO2 values.

Groundwater sampling was undertaken at Baker Farm by CGS scientists Kate Robey and Portia Munyangane with

I GeoClips6

A small CO2 release site near Mjaja was sampled for soil gas, soil flux and water, as two small CO2 seeps were identified within a small stream at the base of the Umtamvuna Mountain. Here, a number of outcrops along the fault trace were identified with kaolinised Dwyka Group tillites. Although CO2 gas was identified in the river course, there appeared to be little to no variation in the soil gas concentrations in the region, suggesting that CO2 gas flux was minimal along this portion of the fault system. Water samples were also collected at the seep and up and down gradient of the seep in the river, but no significant differences were seen in the field measurements.

The Centre for Science and Technology of the Non-Aligned and Other Developing Countries (the NAM S&T Centre) and the Department of Science and Technology (DST) initiated a Training Fellowship on Minerals Processing and Beneficiation Programme. Two scientists of the Council for Geoscience, Marcelene Voigt and Siyanda Mbatyoti, participated in this programme which was hosted and conducted by MINTEK from 12 January to 31 March 2015.

The aim of the training fellowship was to address the skills gap in the

Ian Saunders defined a number of potential sites for the application of microseismic array analysis as well as possible sites for large-scale regional seismic networks to boost the current database which relies on only one station in the Kokstad region. A total of 723 events with magnitudes from ML~0 to ML~3 were located with a single-station location technique from waveforms recorded at the Kokstad station. These earthquakes are located in the vicinity of the Cedarville fault (Matatiele area) with two events focussed on the main Bongwana fault system.

Further collaborative analyses are to be conducted on water and rock

samples collected from the sites, as well as noble gas and stable isotope analyses of gas and water samples which will be undertaken at the University of Edinburgh. The results will be compiled into a report, outlining future work at the sites and hopefully leading to continued international collaboration on the monitoring of the Bongwana and Umtamvuna natural CO2 releases.

For more information contact:Nigel HicksMapping Geology+27 (0)33 341 6265nhicks@geoscience.org.za

Participation in the NAM S&T Centre and DST Training Fellowship

minerals beneficiation value chain by enabling the fellows to update their knowledge on mineral resources. This was done by exposing the trainees to new technologies in the area of mining and minerals. The core objectives of the programme included indirectly addressing the common challenges of sustainable economic development and growth faced by the NAM S&T Centre member countries and other developing countries. The participants were hosted by MINTEK and exposed to two divisions, the Mineral Processing and Mineralogy Divisions, where they received in-service training on various

mineral processing and mineralogy technologies. The following are some of the tests that were conducted:

1. The Wifley Shaking Table tests on samples containing chromite and platinum group minerals (PGMs) from a platinum tailings mine. 2. The Low Intensity Magnetic Separator (LIMS) tests on magnetite rich iron ore samples. 3. The X-Ray Transmission (XRT) tests on coal samples to aid a coal state-owned mine and Eskom. 4. The Teeter Bed Separator (TBS) tests to separate coal from ash. 3. Froth flotation tests at a laboratory scale on samples of the

Marcelene Voigt was trained by MINTEK employees: (A) Conducting froth flotation laboratory tests and (B) Scanning electron microscope analysis.

Siyanda Mbatyoti (second from the left) with the other course participants at

MINTEK’s SAVMIN plant.

(A) (B)

GeoClips I 7Geoclips - Volume 43 - December 2015

Bushveld Complex platinum deposits (e.g. Merensky Reef and UG2 ore), various gold deposits and the Gamsberg base metal deposits. 4. The fellows also received training on X-ray diffraction (XRD) analysis on the Bruker D8 diffractometer of MINTEK. 5. Further training included test work on gold and platinum deposit samples by means of Scanning Electron Microscopy (SEM). 6. The same gold deposit samples were also used for training on the Mineral Liberation Analyser and the QEMSCAN.

Participants came from as far afield as South Africa, Syria, Ghana, Sudan, Burkino Faso, Eritrea, Malaysia, Nigeria

For more information contact:Marcelene VoigtMineral Resources Development+27 (0)12 841 1174mvoigt@geoscience.org.za

and India. Participants were taken on numerous trips and participated in workshops with the general managers of MINTEK. The trips included visits to the SAVMIN plant, the Council for Geoscience, the Chamber of Mines and the Department of Science and Technology. Workshops were conducted on topics such as the Global Minerals Industry and Challenges and Opportunities in Mineral Research and Development.

The participants wish to acknowledge the NAM S&T Centre and the Department of Science and Technology for sponsoring this fellowship and to

extend their appreciation to MINTEK and their staff for sharing their knowledge and experience. A special thanks is extended to Dr Stewart Foya and the Council for Geoscience for the opportunity to participate in this programme.

42nd International Association of Hydrogeologists CongressThe 42nd International Association of Hydrogeologists (IAH) Congress held in Rome from 13 to 18 September 2015 was extremely successful, with more than 950 participants from 84 countries (approximately 30 delegates from Africa) discussing all aspects of hydrogeology. The theme of the AQUA2015 conference was “Hydrogeology – back to the future” and for five days, approximately 700 posters, presentations and keynote lectures reflected on groundwater-related issues of the 21st century. Kate Robey, from the Mapping Geology Competency, represented the Council for Geoscience at the conference by presenting her novel research into the application of in situ iron removal by ozonation as a low-cost treatment option for the supply of drinking water in South Africa.

This presentation discusses the findings from a Water Research Commission funded study into the feasibility of the in situ iron removal technique in a South African context, with reference to the first pilot test being completed at the primary Atlantis Aquifer in the Western Cape.

This research arose from the need to consider alternative options in respect of maintaining the sustainability of many of the wellfields which are

threatened by elevated iron (Fe2+) and manganese (Mn2+) concentrations in the groundwater. While these concentrations cause aesthetic and potable problems, the greatest concern is borehole clogging, which is caused by physicochemical processes and microbiological activities that result in the oxidation of these ions at the borehole and aquifer interface, resulting in lowered yields.

In South Africa, two paramount examples are wellfields in the primary Atlantis Aquifer and the fractured Table Mountain Group Aquifer. Both schemes were developed to supply domestic water to rural communities which experience semi-arid conditions and lack a proximal surface water resource. Although both aquifers are known to be able to supply reliable, good-quality drinking water to the communities, the boreholes in both schemes are currently operating at less than 30 % of their originally assigned yields as a result of clogging.

South African research has focussed on the remediation of clogging problems but knowledge is needed for preventive measures in controlling the source of the problems (i.e. Fe2+ and Mn2+). The in situ iron removal (ISIR) method involves periodic injection of oxygenated water

into the anoxic/anaerobic aquifer. The method has successfully been applied in Europe and elsewhere for decades to reduce the need for above-ground water removal of Fe2+ and Mn2+. In addition, the long-term application of ISIR maintains the borehole yields by reducing Fe2+ and Mn2+ movement towards the borehole screen, spreading the oxidation processes over a larger surface area in the aquifer. Over time, the precipitates stabilise into crystalline oxides, further inhibiting reductive dissolution and Fe2+ and Mn2+ mobilisation.

For more information contact:Kate RobeyMapping Geology+27 (0)21 943 6733krobey@geoscience.org.za

The Sub-Saharan African delegates at the AQUA2015 Congress (photo: M. Dippenaar).

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Council for Geoscience Conference 2016

In pursuit of Excellence in the Geosciences4–5 February 2016

INVITATION

You are cordially invited to the Council for GeoscienceConference 2016.

The two day conference will provide insight into the scientific work of the organisation and will serve as a platform for discussion around various scientific issues that are of national importance.

The conference will bring together local and international experts, researchers, young scientists and decision makers who will exchange their knowledge, experience and research innovations.

Please join us as we build expertise “In pursuit of Excellence in the Geosciences”.

Date: 4 to 5 February 2016Venue: CSIR International Convention CentreCost: R2 000 per delegate

: R1 000 for studentsThis fee does not include accommodation

We look forward to seeing you there!

For general and registration enquiries, please email:CGSConference@geoscience.org.za or log onto www.geoscience.org.za