VOLUME 47

. DECEMBER 2016

INSIDE: Shale gas developments in

Shale gas developments in the the Karoo Basin Karoo Basin I 1 Doug Cole/Haajierah Mosavel

Characterisation of surface dust and trapped dust samples around some asbestos mine dumps in Mpumalanga Province, I 3 Maphuti Kwata

The all new Young Geoscientists’ Network I 4 Refilwe Shelembe Core logging team at borehole site KWV-1 near Willowvale in the Eastern Cape (left to right): Cecil Tivani (UJ), Claire Geel (UCT), Haajierah Mosavel and Doug Cole. First South Africa–Canada Bilateral Collaboration Workshop I 5 Refilwe Shelembe In 2015 and 2016, the Council for subsequent laboratory measurements Geoscience undertook a collaborative of residual gas and Rock-Eval analysis. project with the Karoo Research Initiative Shallow groundwater was sampled from New book on the Bushveld (KARIN) under the auspices of CIMERA wind pumps within a 10 km radius of Complex I 7 (DST-NRF Centre of Excellence for borehole KZF-1 and from boreholes and Maria Atanasova Integrated Mineral and Energy Resource rivers within a 10 km radius of borehole Analysis) with a view to investigating the KWV-1. Artesian water emanating from shale gas potential and the properties depths of between 560 and 670 m in Annual Conference 2017 I 8 and distribution of shallow and deep borehole KZF-1 was sampled, but no groundwater in the Karoo Basin. deep artesian water was encountered in borehole KWV-1. Laboratory Services – new Methane gas is known to occur in the instrumentation I 8 shale of the Karoo Basin. Borehole KZF-1 which had been drilled The provides the to a total depth of 671 m intersected best target for shale gas since it has 657 m of Ecca Group shale overlying similar total organic carbon contents to 14 m of diamictite at several gas-producing shales in the USA the base of the borehole. No dolerite and maturity levels conducive to the was encountered. Black carbonaceous production of dry gas. shale of the Whitehill Formation was intersected at three intervals due to The investigation focussed on core tectonic duplication caused by thrusting. retrieved from two deep boreholes in the Thicknesses from the top downwards Tankwa Karoo (KZF-1) and the vicinity were 19.5 m, 36.25 m and 2.45 m. of Willowvale (KWV-1) in the Eastern Cape Province. Carbonaceous shale The desorbed gas measurements are from the Ecca Group was sampled for very low for the Ecca Group shales, with desorbed gas in the field and sealed for the highest value being 0.047 m3 of gas

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per tonne per day from the Whitehill Formation. Only the Whitehill Formation was sampled for residual gas, with the highest value recorded being 0.56 m3 of gas per tonne, with methane contributing 86 %. The results of the Rock-Eval analysis indicated that the shales are overmature and have a low potential for shale gas.

Borehole KWV-1 was drilled to a total depth of 2 353 m and intersected 410 m of dark-grey shale of the Fort Brown Formation, 13 m of black carbonaceous shale of the Whitehill Formation and 31 m of dark-grey shale of the Prince Albert Formation overlying 15 m of Dwyka Group diamictite at the base of Drilling rig and core boxes at the KWV-1 site near Willowvale. the borehole. 1 245 m of sandstone, rhythmite and shale of the Ripon Formation occur between the Fort Brown and Whitehill Formations. Several dolerite sills up to 150 m intrude the entire Karoo succession. Gas contents are very low with no residual gas present. The highest total gas value recorded was only 0.2 m3 of gas per tonne, derived from a sample of carbonaceous shale from the Ripon Formation. The results of the Rock- Grey shale containing abundant lighter-coloured tuff beds of the Collingham Formation overlying black Eval analysis indicated that the shales carbonaceous shale of the Whitehill Formation at 420.46 m depth. A sample of the Whitehill Formation was are overmature, probably as a result of removed for gas analysis. deep burial and thermal metamorphism associated with dolerite intrusion.

The quality of the shallow groundwater around the KZF-1 borehole site was found to vary significantly, ranging from good-quality potable water to brackish

water with elevated Na, Cl and HCO3 concentrations. The shallow groundwater and surface water in the vicinity of the KWV-1 borehole site was found to be of good quality, based on pH and electrical conductivity measurements. The deep artesian groundwater sampled from borehole KZF-1 consisted of good-quality groundwater emanating from brecciated Prince Albert Formation shale at 560 m depth and brecciated Dwyka Group diamictite at 671 m depth, interspersed with sulphurous groundwater from brecciated Prince Albert Formation pyrite- rich shale at 634.44–637.44 m depth.

The shale gas potential of the Ecca Group shales, including the Whitehill Formation in the two boreholes, was found to be minimal. The shales Shallow groundwater sampling from a borehole near Willowvale with Kate Robey, Doug Cole and Haajierah were found to be overmature owing Mosavel.

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to tectonometamorphic overprinting deep groundwater for the first time. associated with the in This will be a requirement for future For more information contact: the case of KZF-1 and deep burial and regulations, should hydraulic fracking Doug Cole/Haajierah Mosavel thermal metamorphism from dolerite in for shale gas proceed. Knowledge Mapping Geology the case of KWV-1. of the deep groundwater properties +27 (0)21 943 6700 will facilitate empirical investigations [email protected] This research is important, as it into the possible contamination of the [email protected] allowed for the sampling of in situ shallow groundwater.

Characterisation of surface dust and trapped dust samples around some asbestos mine dumps in Mpumalanga Province, South Africa

The of asbestos in South Africa started in the 1800s and ceased in 2002 because of environmental and health reasons. Large operations of asbestos mining in South Africa took place in the Northern Cape, and Mpumalanga Provinces. It is an environmental concern that numerous asbestos mine dumps situated in close proximity to human settlements in the Mpumalanga Province have remained unrehabilitated. Asbestos particles are microscopic in size and can be lifted from ground-based sources by wind erosion or during excavation processes. The purpose of this investigation is to characterise surface dust and trapped dust samples around human Location of the sampling sites in the Mpumalanga Province. settlements that are close to ownerless and abandoned mine dumps. Thus, samples were collected from five sites, with three of these sites (A, B and C) situated close to Mbombela (previously Calcite named Nelspruit), the capital city of Mpumalanga Province. A fourth site, D, Plagioclase is close to Malelane on the eastern side m/m % of Mbombela near the Mozambique Quartz border gate, while Site E is located to Chlorite the southwest of Mbombela.

Amphibole The geochemistry results indicate the presence of oxides of Si, Ti, Al, Fe, Serpentine Mn, Mg, Na, K, P and Cr metals which confirms the predominance of silicate Talc minerals, as indicated by the following

measurements: SiO2 (28.78 to 62.3 %),

Fe2O3 (9.61 to 38.45 %) and MgO Sampling points (14.94 to 41.2 %).

The dominant minerals measured

were chlorite (Mg,Fe,Li)6AlSi3O10(OH)8, Mineralogy data.

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quartz (SiO2), plagioclase (NaAlSi3O8) semirectangular. The size particle (Mg,Fe,Al)5(Al,Si)8O22(OH)2) and mica

and serpentine (Mg3(OH)4(Si3O5). range measured 70 µm to 100 µm (KAI2(Si3AIO10)(OH)2. The non-silicate

The other minerals detected in low for granular, 100 µm to 200 µm for minerals were calcite (CaCO3), feldspar

concentrations were calcite (CaCO3) semitriangular and 200 µm to 500 µm ((KAISQ3O8)-(CaAI2Si2O8)), dolomite

and talc ((Mg3[Si4O10](OH)2). for semirectangular minerals. (CaMg(CO3)2 and clinopyroxene ((Ca,

Mg, Fe, AI)2(Si ,Al)2O6)). The shapes of the amphibole The SEM-EDS data confirmed the

and serpentine minerals detected presence of quartz (SiO2), serpentine The results confirm the predominance

were granular, semitriangular and (Mg3(OH)4(Si3O5)), amphibole (NaCa2 of silicate minerals in trapped and surface dust samples. The significant levels of amphibole and serpentine asbestos minerals measured suggest Composition A B C D E an increased risk of contamination to

SiO2 37.17 28.78 33.62 62.3 33.41 the nearby communities.

TiO2 0.21 0.4 0.05 0.59 0.02

Al2O3 4.87 5.32 1.96 13.4 1.39

Fe2O3 4.48 38.45 9.61 8.01 6 MnO 0.247 0.279 0.079 0.159 0.114 MgO 32.02 14.94 40.94 2.2 41.2 CaO 0.84 0.35 0.01 1.39 0.37 For more information contact: Na2O <0.01 <0.01 <0.01 1.08 <0.01 Maphuti Kwata K2O 0.02 0.23 <0.01 0.74 <0.01 Sustainable Resources and P O 0.046 0.144 0.02 0.176 0.014 2 5 Environment Cr O 0.387 0.393 0.644 0.205 0.229 2 3 +27 (0)12 841 1387 Total 99.64 99 99 99.9 100.2 [email protected] Geochemistry data for sites in the Mpumalanga Province.

The all new Young Geoscientists’ Network

The new committee of the Young Scroll – The symbolic award of success Wiggle in the G – Waves generated from Geoscientists’ Network (YGN) (formerly in education and research (similar a seismograph the Young Science Forum (YSF)), was to obtaining a graduation certificate Last segment of the N – Geological pick elected early in 2016. This presented after hard work, commitment and hammer an ideal opportunity to re-establish determination) and rebrand the network. A new logo All these symbols indicate the was designed by the YGN executive Stars – Excellence applied in research inclusiveness of the YGN and pillars of committee and refined by graphic excellence and hard work to which YGN designer Jane Abraham to reflect the Y – Bonds and molecules of elements members aspire. Anyone up to the age of values of the network. found in minerals 40 is welcome to join the network.

Old logo. New logo.

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The development and progression of MISSION • Encourage excellence in participation in education and innovation in the National projects and programmes Development Plan 2030 of South Africa To create a strong network of active • Invest in commitment and diligence • Uphold principles of continual are the pillars of the YGN vision, mission young geoscientists in the CGS and improvement and values. South Africa

VISION VALUES For more information contact: Refilwe Shelembe To help create sustainable professional • Encourage development through YGN Executive Committee +27 (0)12 841 1098 development for young geoscientists at participation in projects and [email protected] the CGS. programmes

First South Africa–Canada Bilateral Collaboration Workshop

The (CGS) of the workshop was characterised by aureole. The large and extensive hosted the first workshop on Mineralising early morning starts, late nights and Transvaal calc-silicate xenoliths in the Systems of South Africa and Canada winding roads in the Mpumalanga and RLS at type localities visited provided from 17 to 28 October 2016. This was the Limpopo Provinces. The team left for the evidence of this type of contact. The result of the signing of a Memorandum Nkomati Nickel Mine where the models typical extensive chromitite layers (Upper of Understanding and the Implementing of emplacement, crystallisation and other Group (UG) 1, UG 2, UG 3 and the Agreement between the CGS and the controlling factors of the Ni-Cu sulphide Middle Group chromitites) visited at the Geological Survey of Canada (GSC). mineralisation of the Uitkomst Layered Modikwa Mine and the Dwars The main objective of these agreements Intrusion are believed to be coeval and River National Monument characterise is professional development through cogenetic with the Proterozoic Bushveld the RLS and indicate the injection and knowledge exchange, sharing and Complex. The excursion also included mixing of new and old magmas. The building. The themes of the workshop noteworthy discussions around the Canadian Black Thor-Double Eagle covered layered mafic intrusions, intrusive contact between the Transvaal Intrusive Complexes of the Ring of Fire Bushveld-related granites, greenstone rocks and the Layered Suite are also classic examples of chromitite belts, structure-controlled (RLS) and its contact metamorphic (and Ni-Cu-PGE) deposits. The workshop mineralisation and characterisation, craton history and impact structures, to name a few.

The launch of the Mineralising Systems Workshop, which was inaugurated by the opening address of the COO, Dr Mosidi Makgae, mainly featured the rich . A few presentations on similar Canadian themes were undertaken by the delegates from the GSC. The kick-off to the workshop presented the current projects and MTEF tasks of the CGS, such as the prospectivity of the Tugela Terrane, shale gas in South Africa, regional geochemical element distributions in the Bushveld Complex and rare earth elements in the Bushveld Complex. All presentations (except those concerning mines) were given by experts of the CGS and the GSC and these resulted in interesting and thought-provoking discussions. The seven-day excursion Participants of the workshop prior to the commencement of the field excursion.

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group also visited the platinum reef which 1 had been discovered by Hans Merensky in 1924. Today, the adit is still remarkably intact. The pegmatoidal pyroxenites and chromitite stringers found in the adit are good indicators of the position of the platinum reef. Although younger and a product of a meteorite impact event, the major lithologies of the Sudbury Igneous Complex in Canada are similar to those of the RLS.

Gold mineralisation observed at the Sheba Gold and Stibium Mopani Mines and in the Golden Quarry was discovered in the 1800s. These deposits are hosted in the classic Archaean Barberton and Murchison Greenstone Belts respectively and were controlled by brittle and ductile deformation. Pillow lava structures and spinifex textures in the komatiites are classic indicators of the volcanic setting in which the formations in the basal of the Barberton Greenstone Belt had been emplaced. The world-class Barberton Greenstone Belt, which is the largest of the fourteen greenstone belts in South Africa, and the Canadian Abitibi Greenstone Belt, are classic volcanosedimentary sequences which are remarkably similar.

Some of the interesting type localities visited during the excursion that also showcased the geology of South Africa included the Palabora Copper Mine which is the largest open-pit mine in South Africa, hosted by the Phalaborwa Carbonitite Complex (coeval with the Bushveld Complex), the giant stromatolites (stromatolites on steroids) in the dolomitic Malmani Subgroup of the along the Sudwala Pass and gold reefs in the 1. Group at open pit of Nkomati Nickel Mine; 2. In the abyss of the Golden Quarry; 3. Younging direction in Pilgrim’s Rest area in Mpumalanga. pillow structures along the Komati River; 4. Transvaal calc-silicate xenolith in the Rustenburg Layered Suite; The visit to the renowned Vredefort 5. Giant stromatolites of the Malmani Subgroup along the Sudwala Pass in Mpumalanga; 6. Classic UG 1 Impact Structure, the oldest and chromitite layer in the Dwars River National Monument; 7. Studying borehole core in the Stibium Mopani Mine; second largest in the world, was the 8. Pseudotachylitic breccias from the Vredefort Impact Structure. last trip of the workshop excursion. Deformation indicators such as shatter cones and pseudotachylitic breccias Africa and the Superior Craton which The close of the workshop was marked indicate the size and direction of the forms the core of the Canadian Shield by the identification of and agreement on Vredefort impact event and how the in North America. The dyke swarms common areas of collaborative research rocks of the Supergroup on the Kaapvaal and Superior Cratons between the CGS and the GSC. The were overturned. The highlight of the are evidence that these two (and a few success of this Mineralising Systems workshop was an investigation into the others), which may have been rotated, Workshop marks the standing scientific historical development and the links were once fragments of a much larger relationship of these two surveys which between the in South stable platform. will run from 2016 to 2020.

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The workshop organisers wish to thank J.P. Hunt, M. Bensid, V. Mothetha, For more information contact: everyone who contributed towards P. Bosch, T. Dhansay, G. de Kock, Refilwe Shelembe making this workshop a success. The C. Hatton, J. Elsenbroek, L. Mutele, Mapping Geology workshop participants were R. Shelembe V. Nxumalo, S. Hlatshwayo, A. Billay, +27 (0)12 841 1098 (organiser), R. Netshitungulwana W. Bleeker, M. Houlé (GSC), P. Mercier- [email protected] (organiser), N. Baglow (organiser), Langevin (GSC) and C. Lawley (GSC).

New book on the Bushveld Complex Microminerals of the Bushveld Complex South Africa

by Maria Atanasova1, Bruce Cairncross2 and Wolfgang Windisch3 1Council for Geoscience, ; 2Department of Geology, University of ; 3932 Crots Street, Pretoria

The Bushveld Complex is world famous for its spectacular geology and platinum- chromium deposits. It covers an area Microminerals of the Bushveld Complex 2 South Africa of approximately 65 000 km and is 437 PAGES therefore the largest layered complex in the world. It is equally well known for its OVER 1 000 FIGURES esoteric platinum-group mineralogy. Apart from these commodities the Bushveld PHOTOGRAPHS Complex is a source of secondary mineralisation. The main objective of this SEM IMAGES book is to document and publish the occurrence of these secondary minerals 35 SPECIES FIRST IDENTIFIED that occur as microminerals. FOR SOUTH AFRICA

DETAILED REFERENCE LIST For several years, Maria Atanasova and Wolf Windisch have been collaborating in GLOSSARY identifying some of the more unusual and

Maria T. Atanasova interesting minerals from several Bushveld Bruce Cairncross localities. Bruce Cairncross is well known Wolfgang R. Windisch for his mineral work and co-authored and Complex has to offer. Another edited the book. important aspect of this work is that the documentation and publishing of these Valuable SEM data and SEM images microminerals give an insight into the have been generated in this process diversified mineralogy of the Bushveld soil geochemical maps and historical and stockpiled for future use. The Complex other than the well-known photographs and maps. methodology followed has been that of platinum and chrome deposits. traditional mineralogical research: Positive For more information contact: and quantitative identification of minerals Target group readers include researchers using SEM and XRD; fieldwork to of the Bushveld Complex and mines in Thelma Swart document the settings of the mineralised the region, micromount specialists, local Council for Geoscience sites; the utilisation of geological and and international persons interested in +27 (0)12 841 1017 soil geochemical databases to compile the Bushveld Complex and members of [email protected] locality maps using GIS software, and the public who would be attracted by the literature surveys to establish a database beauty of these tiny crystals. This book Council for Geoscience of previous work and gaps in the literature will be a valuable addition to the library +27 (0)12 841 1911 that should be focussed on. of any academic or researcher working [email protected] in Bushveld type layered complexes http://www.geoscience.org.za THE BOOK worldwide. The book is illustrated 280 Pretoria Street, Silverton, Pretoria, The book is in full colour, illustrating the profusely with colour photographs and 0184 magnificent beauty of the microscopic SEM micrographs of microminerals, world of minerals that the Bushveld locality photographs, geological and LIMITED PRINT RUN!

CGS 2016_ Geoclips - Vol 47_ December 2016_ 21-11-2016_ v1.indd 7 2016/11/30 01:39:21 PM “GEOSCIENCE FOR A CHANGING WORLD” A TWO-DAY MINI CONFERENCE PRESENTED BY THE COUNCIL FOR GEOSCIENCE, PRETORIA FROM 2–3 MARCH 2017

The CGS conference will bring together national and international scientists under one roof to discuss matters of geoscientific interest. Within the broad geological mandate of the Council for Geoscience, special emphasis will be placed on prospectivity mapping, marine geological mapping, seismic microzonation, modern methods in geological mapping and aquifer recharge. Internationally renowned experts will participate as keynote presenters and scientists from the Council for Geoscience will present research undertaken for various national programmes. With this annual conference, the Council for Geoscience hopes to provide its stakeholders with insight into all the nationally funded Annual research programmes it has been tasked to undertake. Four pre-conference workshops will also be held dealing with prospectivity mapping, marine geological mapping and seabed mineral exploration, the seismic microzonation of Johannesburg and global events in the South African stratigraphic record. Conference 2017Follow the website for new developments: http://geoscience.org.za/cgs/

Laboratory Services

The Petrography Section is proud to announce the addition of a new Olympus Petrographic Microscope fitted with a 5 megapixel camera to its inventory of instrumentation. This means that we are now able to add good-quality photomicrographs to our petrographic reports. Depending on the client’s publication requirements, the photomicrographs are available in TIF or JPEG formats. In addition, the Petrography Section offers concise and detailed petrographic descriptions. These descriptions include macroscopic descriptions of the specimen, the rock type, the mineral phases present, abundances and textural relations. Detailed petrographic descriptions take this further by adding X-Ray Diffraction (XRD) results, the interpretation of these results in relation to petrographic findings and high-resolution photomicrographs depicting the sample as seen under the microscope.

For more information contact: [email protected]

If you are not on our mailing list and you would like to receive a copy of GEOclips, please send an e-mail to: Mahlatse Mononela, Go to Market, [email protected] Private Bag X112, Pretoria 0001, South Africa / 280 Pretoria Street, Silverton, Pretoria Tel: +27 (0)12 841 1911 / Fax: +27 (0)12 841 1221 / www.geoscience.org.za

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