Physical Properties Probes & Parameters

Measures variation of natural radioactivity emitted by changes in concentration of radioisotopes such as uranium (U), thorium (Th) and potassium (K)
An important parameter for distinguishing rock types, lithology mapping, stratigraphic correlation and detection of alteration zones

Measured rock density is a function of porosity, fluid content and mineralogical composition; heavy elements increase the density signature of the host rock
Used to derive formation porosity, which is defined as the ratio of pore volume to total volume of the rock; plus identification of open fractures
Quantitative in-situ density is valuable for ore tonnage and reserve calculations

A reliable indicator of formation porosity
Calibrated Neutron probes enable quantitative porosity measurement. Relative (qualitative) neutron log can be used to define changes in lithology

Records the full acoustic waveform influenced by the elastic properties of the formation which are related to lithology and porosity
Aids in determination of porosity; calculation of acoustic impedance, compressional and shear wave velocities, detection of fractures; and cement bond logging assessment
Information from compressional, shear and Stoneley waves can be used to calculated mechanical properties critical to geotechnical and mine engineering

Measures the amount of ferromagnetic minerals contained within a volume of rock such as magnetite and pyrrhotite
Identifies changes in lithology, degree of homogeneity and may indicate a zone of alteration
Rapid in-situ magnetite assay estimate

Measures the combined conductivity of rock, soil and pore fluid; inductive method enables logging through PVC casing
Lithology identification distinguish clays, silt and sand; conductive mineralization identification such as massive sulphides

Chargeability is an electrical property measured through induced polarization (IP)
When the current is applied to a body, the electrons will align in the same direction as the electric field generated by the induced current. When the current is turned off, the electrons will remain in alignment for a brief period of time while still producing a measurable voltage. The period that this voltage decay exists will then translate into a measurement of chargeability.
Typically, disseminated massive sulphides will have a high chargeability compared to their host rock

Measures the combined electrical resistivity of rock, soil, and pore fluid; SP – voltage differences due to physical and electrochemical properties of rock and fluid; SPR – electrical resistance along the borehole to a single surface point
Electrical resistivity depends on a combination of: porosity, fracturing, pore fluid salinity, saturation, alteration and mineral composition
Identifies lithology and fracture zones for stratigraphic correlations and may provide contaminant identification based on conductivity of pore fluids; SP highs may indicate base metal sulphides, lows – conductive minerals; SPR increases with grain size and decreases with fracturing and/or greater borehole diameter

Measures changes in fluid temperature, and/or, resistivity related to fluid flow in the borehole
Temperature gradient can identify water flow through cracks fracture or shear zones which can aid structural interpretation and identify potential issues early

Three interconnected arms mechanically measure the borehole diameter
Diameter variations are used to evaluate fracturing, lithology changes, competency of rock, and volume calculations
Borehole diameter is critical, as a constraint or correction for other parameters in a comprehensive borehole geophysics survey

Combination of high-accuracy rate gyroscopes and accelerometers provides directional precision – including in high-magnetic environments and/or inside casing
Eliminates potential for error as surveyed-in reference point is not required
Superior positional accuracy for precise 3D modeling of all borehole information