Borehole Breakout and Fracture Analyses: Jwaneng Kimberlite Mine, Southern Botswana, Africa
Bibliographic record
Abstract
Borehole breakouts, so named by Babcock (1978), are enlargements and elongations of a borehole in a preferential direction. These are formed by spalling of borehole fragments in a direction parallel to the minimum (least) horizontal stress. The breakouts are typically elongated in the direction of the borehole axis and can be expressed by three parameters; orientation in the borehole, the opening angle and the radial depth. Knowledge of the orientation of horizontal earth stresses derived from analysis of borehole breakouts is important to geotechnical and rock mechanical studies. The country rock model for the Jwaneng Mine is extremely complex with a number of major structural faults and splays. The main central fault that intersects the kimberlite bodies has the same orientation as the Zoetfontein fault system 55km to the north (azimuth/dip of 339°/85°). The related fault splays or fractures, are tensile with the main structures and therefore may be fluid conduits. Utilizing downhole imagery in conjunction with the more typical suite of in-situ physical rock property measurements provides constraints on these structures and associated stress fields. Inferences on water mobility through the fracture systems can be made at depth and form an integral part of mine planning, development and optimization.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".