Airborne Ground and Borehole Geophysics For Civil Geotechnical

Airborne, Ground and Borehole Geophysics For Civil, Geotechnical and Environmental

Contents • • INTRODUCTION BENEFITS OF GEOPHYSICS SOLUTIONS CASE STUDIES

Engineering and Environmental Geophysics Exploration Geophysics Mission Improved site characterization by provision of accurate and cost-effective geophysical solutions using siteappropriate geophysical techniques Vision To become a preferred provider of geophysical solutions through innovative and sound application of geophysics

Geophysical Borehole Logging – Data processing – Log Analysis - Innovation

Gyrocopter Light Airborne Geophysics Where Vision Becomes Reality!

Benefits of Geophysics • • • Non-destructive and usually non-intrusive Faster than invasive and destructive methods Able to cover large areas and gives continuous data Proven methods, based on physical parameters which links to geology Cost-effective Quantitative data

Use Geophysics to Investigate • • • Shallow and deep voids in rock concrete or near subsurface materials Fractures, joints bedding and faults: presence, positions and orientation Resistivity profiling for grounding or cathodic protection requirements Depth to bedrock Concrete or tar road investigations Lithological boundaries Water leaks from retainers Local stress (breakout) Geology Geological structure P-wave and s-wave velocities that can aid in establishing engineering parameters such as : – Rippability of Earth materials – Poisson’s ratio – Shear, Bulk and/or Young’s moduli

Choosing Geophysical Methods • Generally a direct trade off exists between resolution and spatial coverage – For example, some downhole logs can measure cm scale anomalies but only in the borehole while large and deep aquifers can be mapped with electromagnetic methods but in very low resolution. – Both will take a day or more to complete • No physical property contrast, no geophysics • Important to the success of any project to choose the correct tool for the geological/geotechnical problem

RESOURCES AND PEOPLE Alten du Plessis (Senior Geophysicist & Manager) MSc Geophysics (Wits) Robert Whitehead (Junior Geophysicist) DP de Villiers (Junior Geophysicist) Equipment MSc Physics 15 years experience BSc Hons (Wits) MSc Candidate Software Field Team Contract Personnel

Open Ground Resources – List of Typical Services • Engineering and Geotechnical – – – – – Mapping of services & utilities Mapping of voids (very shallow < 1 m to deep up to 30 m) Dam Site Investigations to map bedrock depth, quarry sites, fault and fracture zones Ground stability and gravimetric surveys Ground earthing and corrositivity Road pavement investigations (road layers, moistures, shallow voids) Depth to bedrock and thickness of overburden / fill material Stratigraphy and general geology Compressional and shear wave velocity measurements (MASW, down-hole, cross-hole) GPR in underground mining hanging wall investigations: Training and Support • Environmental – – Landfill and groundwater contamination investigations Mapping of preferential groundwater flow paths and permeable layers such as gravels, etc. Mapping of buried objects Mapping of pollution plumes

Case Study 1: Mapping of Buried Objects using Ground Penetrating Radar (GPR) Open Ground Resources was requested by an industrial client to map the presence of buried metal drums containing hazardous material and to confirm the presence and extent thereof. Magnetic and electromagnetic data were previously collected on the site but results were contaminated due to interference from existing infrastructure. Magnetic data displayed above could not be used to infer the presence of the buried drums and interpretation was based on the ‘known’ position of the buried objects. GPR section with strong hyperbolic anomalies interpreted as buried drums The high resolution capability of the GPR technique was far superior to low resolution magnetic and EM techniques and individual drums could be clearly observed. The robustness of the technique with respect to interference from infrastructure makes it ideal for application in industrial environments where maximum detail is required.

Case Study 2: MASW and Surface Waves to Map Fracture Zone in Open Pit Side Wall The dispersion of Surface Waves can be used to provide a rapid means of producing a continuous shear wave velocity section of the shallow subsurface, up to depths of 20 -30 metres can be mapped using a large sledgehammer. The MASW method (Multi Channel Analysis of Surface Waves) was used to map the presence of induced fractures in the sidewalls of a large open-pit. These fractures are pre-dominantly vertically orientated and present a difficult target for conventional geophysical methods as very high resolution are required to map the fracture zones. A series of parallel MASW sections were acquired using a land-streamer system (as shown in Figure to the right). The land-streamer allows for semi-continuous acquisition of MASW data, the streamer is moved at 1 -2 m intervals with sledgehammer impacts shots at the one end of the spread. The MASW results showed a very consistent zone of low shear wave velocity on all three MASW sections next to the open pit, with the reduction in shear wave velocities interpreted from the presence of known fractures. An example of data is shown to the left, with the position of the low-velocity zone indicated. The results could be used to infer the spatial extent of the fracture zones. Advantages of the MASW method Shear wave velocity section with zone of low bedrock velocity at the start of the section clearly visible * No boreholes or difficult shear wave refraction survey are required to produce a shear wave velocity section * Does not suffer from velocity inversions as is the case with seismic refraction *Can be used in industrial areas and on tar/concrete surfaces

Case Study 3: Electrical Resistivity Imaging (ERI) for Lithology and Quarry Investigations at Dam Site A: Very resistive shallow and unweathered dolerite confirmed by drilling, suitable for dam construction material. Drilling confirmed thickness of 30 metres. Electrical Resistivity Imaging has been used for a dam site in Kwazula Natal, to source the depth and lateral extent of dolerite for dam construction purposes. Potential quarry sites were selected based on the visual appearance of dolerite outcrop and ERI was then used to map the depth and lateral extent of dolerite lithology. A total of four quarry sites was investigated, and three sites could be immediately discarded based on the ERI results with a resulting saving in drilling costs and investigation time. Site B: Thin & weathered dolerite on surface underlain by more conductive mudstones; this site was found unsuitable for dam building material.

Case Study 4: Application of Seismic Refraction at Coega Harbour, Port Elizabeth to Map Faulted Quartzite Application of the Seismic Refraction method proved to be a fast and effective means of mapping a block of faulted shallow quartzite encountered during a routine drilling investigation as part of the Coega Project, Port of Nqguru. Initial drilling had to be halted due to logistical and safety issues with the unknown extent of possible shallow bedrock of immediate concern in terms of excavation and harbour construction. Jon Mc. Stay, WSP: “The design options for the terminal, dredge basin and associated infrastructure was thus largely based on the seismic refraction data”. The seismic investigation provided accurate delineation of the shallow bedrock by integration of the seismic results with available borehole information with a quick turnaround time, without any mayor project delays. Data was processed using Seis. Opt 2 D and bedrock velocity ranges was contoured to image bedrock datum elevation as shown to the left.

Case Study 5: Electrical Resistivity Tomography to Map Concrete Integrity for Tower Foundation Electrical Resistivity Tomography (ERT) was used to evaluate the integrity of soil-crete foundations columns which was found to be inconsistent in depth and diameter when investigated after column construction. It was found that the columns were thinner in places than the design parameters, and concrete was also entirely missing at certain depths. The Supersting R 8 8 -channel Resistivity system was used to acquire ERT data between 3 boreholes using two cables with 28 electrodes each @ 0. 5 m spacing. The powerful 8 channel capability of the Supersting allowed for the collection of more than 5000 measurements in approximately 4 hours, allowing for high measurement density and stable inversion results. Footprint of Tower Foundation with soil-crete colomns. Boreholes used for tomography survey indicated in red.

Wireline Logging Precision, objectivity and continuity are the key attributes of geotechnical wireline data.

Downhole methods Wireline Worksop specialises in developing custom solutions to our clients problems Current capabilities include: • • Optical and acoustic televiewer Resistivity Sonic transit time Natural gamma Density Temperature Three-arm caliper Porosity and permeability

Optical televiewers work best in clean dry holes but will work perfectly well in clean water – sometimes it’s worth cleaning out a borehole before logging it. Advantages • Virtual core • Continuous • In-situ • Orientated What can we gain from this data? • Bedding, joints, fractures, voids • Lithology

Optical televiewer

Sonic log Tight layer Density log Describes lithology

Full Waveform Sonic log With P and S waves, we can calculate the dynamic moduli of elasticity Semblance Need to measure the P-wave first arrival time and the Swave transit time

Acoustic televiewer Juxtaposition with density

Acoustic televiewer - DIFs Drilling induced events must be recognised and purged from derived logs.

Acoustic televiewer - Breakout

Acoustic televiewer – Stress rotation In this example the stress orientation, indicated by breakout, has rotated by 55 degrees. A nearby fault is indicated.

Acoustic televiewer – picking Images Manual picking involves placing a projected curve over a fracture plane and classifying the type of event picked. Automatic picking is available. It is quicker but lacks detail and certainty. Basic structure classification might include: • Sedimentary bedding • Veins • Lithological boundaries • Fractures • Faults

Acoustic televiewer – fault drag and block rotation

Structure logs – presentation

Wireline logs offer • Continuous measurement (no gaps) • Objectivity (not an opinion) • Precision (repeatable and vertically proportional / one event) • In situ measurement • Accuracy (via calibration or empirical conversion) • High resolution of televiewer images • Orientation of fractures and bedding • Aperture of open fractures • Orientation of maximum horizontal stress tensor • A permanent digital record (easy manipulation and transmission)

Limitations of wireline logging • Some logs cannot be captured in dry holes (sonic data) • Density has relatively poor resolution • Sonic logs are not necessarily measuring IRS • Shear waves cannot be measured in slow formations • Empirical data are needed for UCS and elastic moduli conversion • Optical televiewer is superb…but needs a clean hole and/or clean water • Proper planning to circumvent these limitations is necessary

List of Services • • • Training in data capture (field operations) Training in logging theory and radiation safety Advising on logging modus operandi / planning field operations QA of logs and logging contractor's procedures (in the field) Intervention services (problem solving during operations) Data processing and presentation to best effect Log analysis and derivation of relevant outputs Formal project reporting with conclusions and recommendations Presentation of results

Gyrocopter Light Airborne Geophysics Where Vision Becomes Reality! Presented by Dr. Laurent AMEGLIO (Gyro. LAG – CEO & Technical Director)

Disclaimer & Forward-looking Statements This document/presentation (the “Document”) has been prepared by Gyro. LAG (the “Company”) solely for information purposes only and shall not be regarded neither as a proposal, acceptance, nor as a statement of will or official statement from Company and/or subsidiaries and/or affiliates and/or associates. This Document is the sole responsibility of the Company. Information contained herein does not purport to be complete and is subject to certain qualifications and assumptions and should not be relied upon for the purposes of making an investment in the securities or entering into any transaction. The information and opinions contained in the Document are provided as at the date of the Document and are subject to change without notice and, in furnishing the Document, the Company does not undertake or agree to any obligation to provide recipients with access to any additional information or to update or correct the Document. In preparation of this Document, Company has exercised reasonable skill, care and diligence. The statements, conclusions and recommendations contained herein might be based upon data obtained from third parties. No warranty or undertaking is made in respect of information that was obtained and used in this Document and which, unknown to Company, was incorrect or incomplete. Neither Company, nor any of its employees, nor any of their contractors, subcontractors or their employees, nor any of its Associates and shareholders, makes any warranty, express or implied, or assumes any legal liability or responsibility whatsoever for, or in respect of, any use of, or reliance upon, this Document by recipient or any third parties, or if it is used by Recipient or any third parties, for any other purpose than originally intended. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favouring by Company or its contractors or subcontractors. The views and opinions of author(s) expressed herein do not necessarily state or reflect those of Company. This document may contain "forward-looking statements and information” that are based on the Company's current expectations, estimates and projections about future events and financial trends affecting the Company. Forward-looking statements and information can be identified by the use of words such as "may, " "will, " "should, " "expect, " "estimate" or other comparable terminology. Forward-looking statements and information are inherently subject to risks, uncertainties and assumptions, many of which the Company cannot predict with accuracy and some of which the Company might not even anticipate. Important factors, which may affect these expectations, estimates and projections and may cause expectations, estimates and projections to differ materially from those expressed in the forward looking statements and information contained herein, include, but are not limited to: (i) continued availability of capital and financing; (ii) Company's ability to borrow on favourable terms; (iii) general economic, market, business or governmental conditions; (iv) adverse changes in the airborne geophysics markets including, among other things, increased competition with other companies, market prices; (v) risk of airborne surveys acquisition and development, including, among other things, risks that projects may not be completed on schedule, that Clients may not or delay payment for services rendered by the Company to them, or that development or operating costs may be greater than anticipated; (vi) risks of investing through joint venture structures, including risks that the Company's joint venture partners may not fulfil their financial obligations as investors or may take actions that are inconsistent with the Company's objectives; (vii) environmental requirements. Accordingly, the Company can give no assurance that these expectations, estimates and projections will be achieved. Future events and actual results may differ materially from those discussed in the forward-looking statements. Gyro. LAG – Company profile 33

Technologies Industries Magnetic Gamma spectrometry Digital video Aerial photo Thermal imaging Laser scanning Scalar gravity Multi- and Hyper-spectral Self-Potential (Experimental) Electromagnetic (R&D) Mining Security Environment Civil Engineering Water Exploration Mineral Exploration Geological Mapping Precision Agriculture Oil & Gas Exploration Where Vision becomes Reality ! www. gyrolag. com info@gyrolag. com

Gyro. LAG – About the company Gyro. LAG (Pty) Ltd (Gyrocopter Light Airborne Geophysics), headquartered at Potchefstroom airport (South Africa, 26° 40"05' S / 027° 05"05' E WGS 84), brings to reality the next generation of advanced and innovative airborne multisensor geophysical platforms to the natural resource exploration, environmental, civil engineering and precision agriculture industries. Established in 2011 in Johannesburg, the vision of Gyro. LAG was to develop a small and stable multi-sensor platform, resulting in highly flexible surveys flown at low/reasonable cost of operation. Gyro. LAG is 'Where Vision Becomes Reality'! Gyro. LAG owns complete airborne geophysical systems which are installed on board customized gyrocopters (our flagship aviation platforms - see technical profile below) and one light fixed-wing aircraft, suited for a wide range of topographic and environmental conditions. By using latest technological developments and out of the box thinking in both airborne carriers and geophysical and geomatics sensors, Gyro. LAG is available to carry out specialized airborne surveys to individuals, consultants, exploration companies, government entities, farming and environmental groups. Customizing its aircraft, Gyro. LAG also provides an uncompromising commitment and culture to 'Safety by Design, Not by Default'! Gyro. LAG – Company profile 35

Gyro. LAG – Tool box Gyro. LAG's selection of technology for geophysical and remote sensing applications are presented on the right with: two three-components fluxgate magnetometers (a to d); gamma-ray spectrometers (4 ltr Cs. I and 16 ltr Nal with full spectrum analysis – e); scalar gravimetry (1 m. Gal accuracy for 2 km full wavelength resolution – f); a CCD digital video/aerial photos system (g); a thermal imaging camera (h); a laser scanner - Li. DAR (i); DTM (j); data interpretation products e. g. physical geology (k) and structural map (l). Gyro. LAG – Company profile 36

Gyro. LAG – Industries and applications By using latest technological developments and 'in new box' thinking in both airborne carriers and geophysical and geomatics sensors, Gyro. LAG is available to carry out specialized airborne surveys to individuals, consultants, exploration companies, government entities, farming and environmental groups along three main applications: ROC - Resources Observation Carrier. . . Light aircraft airborne geophysics and geomatics for the natural resources exploration (mineral, water, oil and gas, etc). (The Roc is a legendary bird of prey from Eastern mythology) LEAF - Light Environmental & Agricultural Flying. . . Light aircraft airborne geophysics and geomatics for the precision farming and environmental industries. (The ginkgo leaf is a living fossil dating back 270 million years) ACE - Airborne Civil Engineering. . . Light aircraft airborne geophysics and geomatics for the civil engineering industries for roads building to mine infrastructures. Gyro. LAG – Company profile 37

Gyro. LAG – Products TMI DTM NIR K Th U Ternary Tilt TIR Tot. C Photo Gyro. LAG – Company profile Li. DAR 38

Gyro. LAG – Interpretation products Gyro. LAG is also an exciting infusion of cutting edge science and expert interpretation that transform data into knowledge: Sub-outcrop geology map extrapolated from geophysical data and 2 D models for PGE exploration. Airborne total magnetic field map with selected targets (e. g. for REE exploration). Magnetite (green) and pyroxenite (beige) parts of a carbonatite complex in Africa. Gyro. LAG – Company profile 39

Gyro. LAG – Technologies Devoted to the development of innovative and cutting edge airborne technologies and solutions, Gyro. LAG brings the following bouquet of unique technological and geo-scientific applications to the industry: FLAME – FLuxgate Airborne Magn. Etic. . . an association with Unistra (France) POFADER – POtential Field Airborne DEtection & Record SWIFT - Short Wave In. Frared Technology. . . A unique near- or short-wave infrared spectral profiler for geological and mineral mapping. Under development. Gyro. LAG – Company profile 40

Gyro. LAG – Research and development Gyro. LAG has also established strong ties and partnerships with academic and scientific entities at: UNISTRA - University of Strasbourg (France). . . development in airborne fluxgate magnetic surveying. NMMU & AEON - Nelson Mandela Metropolitan University (South Africa). . . AGEO - Airborne GEophysics Observatory. TUT - Tshwane University of Technology (South Africa). . . contributing to the airborne geophysics component of TUT's Science & Technology Train project. Gyro. LAG – Company profile 41

Gyro. LAG – Research and development NWU - North West University (South Africa). . . development on airborne geophysics for precision agriculture and environmental applications. Under discussion. Hochschule Koblenz & Fraunhofer - University & Research Institute (Germany). . . development NIR and TIR airborne mapping. Gyro. LAG – Company profile 42

Gyro. LAG – Trading innovations Gyro. LAG also invite you to join its . . . FEEL - Frequent Executive Explorer League . . . the world first and unique frequent airborne geophysics flyer program. With FEEL you earn valuable miles when you fly airborne geophysics or remote sensing with Gyro. LAG. You can redeem your miles for new airborne geophysical surveys with Gyro. LAG, special interpretation products, and much more. Depending on the number of miles you earn within a period, you can also achieve status and enjoy many special and exclusive geophysical privileges for your exploration and mining activities. Gyro. LAG – Company profile 43

Gyro. LAG – Trading innovations Gyro. LAG is also a founding member of Assegai Geophysics (www. assegaigeophysics. com), a consortium of geophysical consulting and contracting companies led by a team of industry experts with more than 100 years of combined experience worldwide and with a strong Africa focus. Assegai Geophysics is the portal of choice for integrated tailored geophysical solutions in airborne, ground, marine, wireline and data modelling applications to the natural resources exploration, environmental, civil engineering and precision agriculture industries. Gyro. LAG – Company profile 44

Gyro. LAG – Trading innovations Gyro. LAG is also now offering its gyrocopter airborne geophysics platform as a franchise with two configurations: FLAG platform (Fly Light Airborne Geophysics) FLARe. S platform (Fly Light Airborne Remote Sensing platform) Gyro. LAG – Company profile 45

Gyro. LAG – Applied Research Centers Gyro. LAG teamed up with AEON, the Earth Stewardship Science Research Institute at the NMMU (South Africa), setting up AGEO to provide light airborne geophysics support to earth systems science research projects, linking marine to continental environments. Gyro. LAG – Company profile 46

Gyro. LAG – Applied Research Centers Gyro. LAG is looking for an academic entity interested to contribute to its 'X-farm' program to provide the agriculture industry with a state-of-the-art affordable light airborne remote sensing (inc. geophysics) support for crops and farm management. Gyro. LAG – Company profile 47

Gyro. LAG – Aviation Gyro. LAG fleet is made of unique and versatile light airborne platforms that provide a blend of capabilities to perform effectively in any surveying environment. Gyro. LAG – Company profile 48

Gyro. LAG universe Gyro. LAG and its partners have created a compelling momentum at the cutting edge of airborne geophysics. We interface a research & innovation hub and a commercial hub pulling together unprecedented forces to provide the industry with unique and tailored solutions and services. Gyro. LAG – Company profile 49

Gyro. LAG – Offices Gyro. LAG South Africa ATC Tower, Potchefstroom Airfield (South Africa) (WGS 84) 26° 40"05' S / 027° 05"05' E Mail: P. O. Box 21153, Noordbrug 2522, South Africa E-mail: info@gyrolag. com Web: www. gyrolag. com Reg. no. : 2011/129433/07 Gyro. LAG Botswana Unit 7, plot 101, Commerce Park, Gaborone, Botswana Mail: P. O. Box 95 ADD, Postnet Kgale View, Gaborone, Botswana E-mail: info@gyrolag. com Web: www. gyrolag. com Reg. no. : CO 2013/12910 Gyro. LAG Australia 179 Back Yamma Rd, Parkes, 2870, NSW, Australia Mail: 179 Back Yamma Rd, Parkes, 2870, NSW, Australia E-mail: info@gyrolag. com Web: www. gyrolag. com Gyro. LAG – Company profile 50

Gyro. LAG – Around the world Gyro. LAG – Company profile 51

Gyrocopter Light Airborne Geophysics Cell. : +27 84 787 1000 Email: laurent@gyrolag. com Web: www. gyrolag. com Where Vision becomes Reality!