Effect of Size-Biased Sampling on Resource Predictions from the Three-Part Method for Quantitative Mineral Resource Assessment—A Case Study of the Gold Mines in the Timmins-Kirkland Lake Area of the Abitibi Greenstone Belt, Canada
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- Document: Report (872 kB pdf)
- Related Works:
- Techniques and Methods 7-C14: User’s guide for MapMark4—An R package for the probability calculations in three-part mineral resource assessments
- Techniques and Methods 7-C15: Probability calculations for three-part mineral resource assessments
- Companion File: Scripts (1.31 MB zip)
- Download citation as: RIS | Dublin Core
Abstract
The three-part method for quantitative mineral resource assessment is used by the U.S. Geological Survey to predict, within a specified assessment area, the number of undiscovered mineral deposits and the quantity of mineral resources in those undiscovered deposits. The effects of size-biased sampling on such predictions are evaluated in a case study that involves gold mines from the Timmins-Kirkland Lake area of the Abitibi greenstone belt, Canada. The gold mines are divided, based upon the time of the assessment, into two groups: existing mines and future mines. The total produced gold for the existing mines are used to predict, with the three-part method, the total produced gold for the future mines. Then the predictions are compared to the known, total produced gold for the future mines. For comparisons using the mean, the predictions are 1.6 to 12 times too high, depending upon the time of the assessment and the probability density function characterizing the total produced gold in the existing mines. For comparisons using the median, the predictions are 1.3 to 10 times too high, depending upon the time of the assessment. The reason for these excessively high predictions is that the three-part method is based on the assumption that the total produced gold from the existing mines is representative of the total produced gold in the future mines; this assumption is inappropriate because of size-biased sampling. There is reason to be concerned that size-biased sampling adversely affected the resource predictions of previous U.S. Geological Survey assessments that were conducted with the three-part method.
Suggested Citation
Ellefsen, K.J., 2019, Effect of size-biased sampling on resource predictions from the three-part method for quantita-tive mineral resource assessment—A case study of the gold mines in the Timmins-Kirkland Lake area of the Abitibi greenstone belt, Canada: U.S. Geological Scientific Investigations Report 2018–5149, 15 p., https://doi.org/10.3133/sir20185149.
ISSN: 2328-0328 (online)
Study Area
Table of Contents
- Acknowledgments
- Abstract
- Introduction
- Background
- Three-Part Method
- Evaluation of Predictions from the Three-Part Method
- Discussion
- Future Research
- Software and Reproducibility
- References Cited
- Appendix 1. Data Compilation
- Appendix 2. Sample Space
- Appendix 3. Requirements for Datasets
| Publication type | Report |
|---|---|
| Publication Subtype | USGS Numbered Series |
| Title | Effect of size-biased sampling on resource predictions from the three-part method for quantitative mineral resource assessment—A case study of the gold mines in the Timmins-Kirkland Lake area of the Abitibi greenstone belt, Canada: |
| Series title | Scientific Investigations Report |
| Series number | 2018-5149 |
| DOI | 10.3133/sir20185149 |
| Year Published | 2019 |
| Language | English |
| Publisher | U.S. Geological Survey |
| Publisher location | Reston, VA |
| Contributing office(s) | Geology, Geophysics, and Geochemistry Science Center |
| Description | Report: v, 15 p.; Companion File |
| Country | Canada |
| Other Geospatial | Ontario Province, Quebec Province |
| Online Only (Y/N) | Y |
| Google Analytic Metrics | Metrics page |