HolmesCo: Gold Assay Results
Week 6 handout — Base rates and conditional probability
This is a fictional document for teaching purposes.
HolmesCo
Geological Consultants Since 2019
“Where There’s a Test, There’s Gold”™
PRESS RELEASE — FOR IMMEDIATE DISTRIBUTION
Date: March 2026
Major Gold Discovery in County Durham
HolmesCo is pleased to announce the results of a landmark geochemical survey across County Durham and the Northern Pennines.
Survey methodology
Our field teams collected soil and shallow rock samples from 1000 locations across the survey area. Each sample was tested using HolmesCo’s proprietary AuDetect™ geochemical assay, which identifies gold-bearing rock with 95 % accuracy:
- If gold is present, the assay correctly identifies it 95 % of the time (sensitivity)
- If gold is absent, the assay correctly rules it out 95 % of the time (specificity)
Results
Of the 1000 samples tested, 54 returned positive results for gold mineralization.
The positive samples are concentrated in the western part of the survey area, consistent with known geological structures in the Alston Block.
Interpretation
“Fifty-four confirmed gold hits across County Durham represents a highly significant discovery. Our AuDetect™ assay is 95 % accurate — these results give us great confidence that there is genuine gold mineralization in the region. We recommend immediate follow-up drilling at the most promising sites.”
— Dr G. Holmes, Chief Scientific Officer, HolmesCo
HolmesCo has applied for three exploration licences and is seeking investment partners to fund a Phase 2 drilling programme.
Investors interested in this opportunity should contact HolmesCo’s Business Development team.
This press release has been prepared by HolmesCo and has not been independently reviewed. AuDetect™ accuracy figures are based on laboratory validation against known reference samples. Field performance may vary. HolmesCo accepts no liability for investment decisions made on the basis of this announcement.