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We offer a wide range of geophysical techniques suitable for many all-deposit types and mineralisation styles in NZ’s rugged, highly vegetated and remote terrain. These techniques combined with our comprehensive post-acquisition consulting services are sure to suit the scale and purpose of most land-based exploration and investigations programmes across metalliferous, placer and hydrocarbon geological settings. We also have techniques suited to groundwater and geotechnical site characterization and design applications.

SGL's preference is to work collaboratively with clients to achieve the best marriage technique and objectives. This requires that the client’s needs and site constraints are clearly understood, allowing selection and design of the most suitable geophysical survey method(s). SGL prides itself on being agile, innovative, responsive and working efficiently to deliver quality results in the shortest time possible.

SGL's preference is to work collaboratively with clients to achieve the best marriage technique and objectives. This requires that the client’s needs and site constraints are clearly understood, allowing selection and design of the most suitable geophysical survey method(s). SGL prides itself on being agile, innovative, responsive and working efficiently to deliver quality results in the shortest time possible.

Why geophysics?

Geophysics is an excellent, normally non-invasive method for exploring the subsurface at all scales of practical interest. It is quicker and more cost-effective than relying solely on traditional invasive techniques such as drilling. It can be used to define target zones of interest or to provide continuous surface and subsurface data unlike traditional exploration methods like mapping, trenching and drilling.

Good quality data start with a clear understanding of your objectives, followed by careful survey design, planning and execution. Credible images of surfaces and mineralization anomalies will emerge through high-quality field equipment, continuous QA/QC, high quality processing software, routines and experienced personnel.

Outputs are formatted into the client’s coordinate system for easy incorporation into the model. In this way, the results will quickly help define and improve the client’s understanding of the geology and mineral resources being explored.

Geophysics is a time-honoured technique that if done right can result in significant exploration cost savings and increase the chance of a successful mining operation. We can add value by

What we offer

SGL offers a full/wide range of Ground Penetrating Radar, Seismic, Magnetic, Resistivity, Polarisation, Time-domain Electromagnetics, Gravity and metal detection geophysical exploration services. Appropriately applied, these methods will define anomalies, geological features and potential mineralisation, and changes to the geology from historic mining or natural processes. Other surveys we do relate to material characterization and groundwater.

SGL can also provide aerial and downhole survey solutions:

  • aerial surveys using fixed wing and multi-copter drones (UAVs) equipped with various high-payload sensors to enable capture a range of geophysical data such as ….
  • wireline (or downhole) logging. This well-established technique complements drilling to optimise data capture and reduce the risk of data loss in any exploration or investigation programmes.
  • Recovery and reprocessing of historic geophysical data
  • Post processing data domain conversion
  • Help with locating and characterizing the mineral resource
  • Tools to quantify a reserve
  • Downhole data analysis and interpretation using WellCAD
  • Expertise in data acquisition and problem solving
  • GIS mapping
  • Collaborative data analysis, reporting and interpretation

We can add value to your data in several ways. Our exploration and mining consulting services include:

Mineral Exploration

Seismic reflection: The requirements of exploration for oil, gas and coal are varied, and depend on the size and depth of the target, the material properties of the overburden and the terrain being explored. We are experienced in designing and implementing seismic surveys, and are well-practiced in meeting the unique challenges of exploring New Zealand’s backcountry.

We offer both 2D and 3D seismic reflection surveys to image basin structure and stratigraphy. We can acquire both P-wave seismic reflection for on land targets (down to 1km), as well as higher resolution P-wave and S-wave surveys for coal and other stratabound deposits nearer the surface (50-300m).

Imaging contacts, horizons and faults with 3-5m thickness and offsets is possible with good survey design, high-quality acquisition and careful processing. Typical applications include elucidating deep basin-scale geology, identifying small-medium scale structure for geological modelling, highwall design and mine planning. Data is inverted to depth domain for ready inclusion into your geological model.

Seismic refraction tomography (SRT): is useful for imaging depth to horizons and lithological changes to depths of around 50m.

Ground Penetrating Radar (GPR): SGL owns and operates NZ’s biggest range of antennas (100 – 2,700 MHz) for surveying targets ranging in depth between 10mm down to 25m. delineating and mapping the extent of overburden in gravelly soils. We can determine the thickness and 3D structure of individual gravel layers allowing forward planning and site development to be undertaken at much lower cost than traditional intrusive investigations.

GPR can be used to determine the thickness and continuity of beach sands, river channels and gravel lags that may be host to alluvial gold and other mineral sands. It can also detect coal seams and mine voids in the subsurface.

Multi-channel Analysis of Surface Waves (MASW): can be useful for identifying changes in stratigraphy and lithology across a site and depth to bedrock.

Electrical Resistivity Tomography and Induced Polarisation (ERT/IP): these complementary techniques can be used to detect sulphide mineralisation and the presence of burnt coal seams.

Magnetics/Gravity: Large scale structure and basin studies.

Bedrock profiling: Subject to the depth of the interest and technical constraints, we can carry out a bedrock survey using one or more of the following techniques - GPR, seismic, and MASW. Selection of the best method is a case-by-case decision. Applications include determining overburden depth across quarries, the depth and sedimentary structure of placer deposits, locating historic mine voids, depth of dredging and the extent of old backfill across a site.

​Equipment and Software

SGL owns and operates a wide range of best-in-class equipment and processing software.

Data capture systems:

  • Geometrics 96 channel seismic reflection/refraction system (P-wave and S-wave)
  • Tigre 128 channel ERT/IP system
  • ZZGeo 64 channel ERT/IP system
  • Seven GSSI GPR systems for high frequency/resolution concrete void and condition surveys to hyperspectral low frequency surveys for deeper mining applications.
  • Geonics EM61 metal detector
  • MASW


  • CAD
  • ArcGIS
  • WellCAD
  • ReflexW, Global Claritas, Surfseis, Refrac, RES3D etc
  • Leapfrog - geological modelling and visualization


SGL’s approach to quality assurance policy is based on technical excellence, professionalism, appropriately trained staff, and compliance with all relevant regulations. attached policy. Our equipment is maintained and calibrated in accordance with manufacturer and ASTM specifications.


SGL is committed to ensuring the safety of its personnel and the environment. We operate in accordance with the HSAW Act 2015 as it applies to remote areas and high hazard sites, such as mines and quarries. We risk assess and manage our field work in co-operation with the client to ensure it meets their HS&E standards and expectations.
We are SiteSafe and SiteWise green accredited. Our field staff have significant experience working in remote parts of New Zealand and first responder training.
Our staff are highly competent and qualified for field operations, including explosive and shotgun licenses, confined space training, first aid, and 4WD experience.

Exploration Projects Manager

Dean Fergusson has over 35 years of experience in mineral exploration, projects and mining operations throughout New Zealand.  He has a BSc and MSc (hons) in Earth Science from University of Waikato. He is a long-term member of AusIMM and is a chartered professional geologist. He successfully implemented and managed multiple, high-resolution 3D seismic reflection surveys in NZ’s highly-structured coal basins, developing work-flows to map, model and risk assess geological hazards in mine feasibility and operational planning. He is highly conversant with wireline logging techniques and data interpretation and the applied use of GPR for site investigations. Dean brings a wealth of project management experience and knows first-hand how to successfully apply geophysical techniques in mining and geotechnical end uses.