Intercept

The length of mineralised rock a drill hole passed through, quoted with its grade.

Definition

The length of mineralization encountered in a drill hole, typically reported with grade information. For example, '10 meters at 5 g/t gold' means the drill hole encountered 10 meters of material grading 5 grams of gold per tonne.

Why it matters

Intercepts are the raw output of exploration and the main driver of junior share prices. A single spectacular hole can re-rate a company before anyone knows whether it repeats.

In practice

Read grade and width together — 50m at 1 g/t and 5m at 10 g/t contain similar metal but imply very different mines. Then check whether the width quoted is true width or downhole length.

Where people go wrong

Headline intercepts are chosen by the company. Look for the full table of results, including the holes that missed, and for how the composite was calculated.

See also

  • True Width The actual thickness of a mineralized zone measured perpendicular to its orientation. Drill holes rarely inter
  • Grade (g/t) The concentration of a valuable mineral within ore, typically expressed in grams per tonne (g/t) for precious
  • Assay The chemical analysis of rock, soil, or drill core samples to determine the concentration of valuable minerals
  • Drill Program A systematic exploration program using diamond or reverse circulation drilling to obtain subsurface samples fo

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