Geophysics Analysis & Interpretation


We produce a large number of radiometric maps (around 150 for a typical airborne rad survey) representing the basic analysis of the distribution of radioelements and their ratio. None of the map is redundant. Each map provides quantitative or visual nuances that enhance the interpretation. Besides performing traditional filtering we also apply more advanced maps using our technologies. 

Then we produce a number of more advanced analysis, statistics and maps. We integrate other datasets to better quantify the radiometric anomalies and the alterations.

Accurate Gridding

To achieve the high resolution mapping that we produce, traditional commercially available gridding techniques (Least square, linear, nearest neighbour, or kriging, etc) do not suffice. Our proprietary techniques have the ability to emphasize very small, local vs regional anomalies. This is particularly needed to select small targets. 

Basic Mapping of the Radioelements Ratios 
These are maps reveal the radiometric anomalies and how they differentiate from surrounding rocks. We also calculate and map the ratios “between” elements and interpret the results to advance the understanding of the lithology. The results are maps of zones of element enrichment and depletion and analysis of interconnection between anomalies. 

Zones of Alteration, Mineralization
Preliminary interpretation of zones of alteration, mineralization, and preliminary interpretation of the source of anomalies. These maps include contours of anomalous zones of particular interest on the ternary maps, as well as preliminary lithology i.e ultramafic, mafic, felsic, etc.


Advanced Radiometric Mapping
TerraNotes has researched and developed a number of more advanced radiometric analysis techniques to differentiate in greater detail the attributes of anomalies and zones of alteration. These enhanced distribution maps often compare ternary and enhanced ternary maps, e.g. eTh/K on K may potentially illustrate the location of potassium alteration zones. They provide a lot of information about fundamental mineralogy and geochemical properties of bedrock and surficial alterations, possible deposits, often indicating geological features not seen by other techniques. These maps eliminate the cultural effects (topography highs/lows, waterbodies) or processing flaws due to altitude correction. Thus, the anomalies reflect the lithologies and alterations only.

URANIUM: Ternary maps specific to uranium exploration
TerraNotes has developed the INDEX OF DIRECT DETECTION OF U MINERALIZATION.  Our algorithm searches for a number of Radioelement Parameters and then maps the coincidence of these items with each other. The black polygons on the 1st map below delineate coincident blue anomalies on both maps indicating significant amount of uranium mineralization.
The 2nd map below illustrates these Radioelement Parameters as individual contours and as composite indices. These zones - particularly the red and yellow zones - may form the high priority zones for further uranium exploration. This procedure allows us to find the uranium mineralization of greatest interest near surface.
TERNARY MAPS: We produce a large number of ternary maps. We are finding that they are very useful at the interpretation stage. For instance, the 3d map below shows the uranium distribution map versus uranium alteration map. Coincident blue (left panel) and red (right panel) colours form the regions of interest for further exploration. We also produce radioelements differentiation maps. For example, the 4th map below represents the K differentiation which can be used to find K-rich lithologies and to differentiate the attitude of the the K enrichment zones. Of course we use these procedures for each element as well as inter-elements ratios. 

RADON TRACKS on TERNARY ELEMENTS: We prepare a number of maps and interpretation of the soil U and radon tracks integrated to ternary radioelements maps. For example map 5 below where the blue ellipses represent regions of interest at a very local scale. Map 6 below shows an example of the linear relationship - inverse relationship - between radon tracks and other elements (e.g. Rd vs. U).

PORPHYRIES: Maps specific for the interpretation of porphyries
TerraNotes has developed a workflow and mapping specific for the interpretation of porphyries. The deposits are generally characterized by an association with porphyritic intrusions, by overprinting propylitic, potassic, and phyllic alteration, by disseminated or fracture-controlled sulphides, and by metal zonation (Various authors 2005, 2010). There are nuances and difference in the geophysical signature of different types of porphyry. Also, lythocaps developing over mineralized intrusions can mask signatures. Therefore, attention must be paid to the quality of maps and interpretation. 

Our geologist and geophysicists review and analyse the maps described above. A number of radiometric anomalies, zones of alteration and areas of interest will be selected, analyzed and prioritized. 
We have researched and developed technologies that improve the qualitative and quantitative interpretations at the reconnaissance scale, at the local scale or at the drill grid scale.

Our team has what it takes: The proper interpretation requires the examination of all of the measured variables and associated derived product. Our interpretations involve knowledge of the following:

  • How the acquired radioactive element distributions correlate with normal lithologic signatures;
  • How these normal lithologic signatures are recognizably modified by mineralizing processes (alteration signatures);
  • How these lithological and alteration signatures are incorporated into surficial materials;iv) how these surficial materials can be spatially related to bedrock sources (inspired from Shives et al, 1995-1997). 
  • Our expertise ability and methods are directed toward addressing these four basic problems of effective radiometric interpretation.

The interpretation includes the following:

  1. Radiometric interpretation of the geophysical maps produced in the above deliverables and prioritization of zones of interest.
  2. Integrated  interpretation and prioritization of zones of interest.
  3. Geology/lithology/alterations and mineralization interpretation.