Current Log Summary
Results update when interval values change.
Project and Drill Hole Details
Core Interval Log
Add one row for each logged interval. Calculations run automatically.
| # | From (m) | To (m) | Interval (m) | Box | Row | Run | Sample ID | Recovered (m) | Recovery % | RQD length (m) | RQD % | Rock type | Lithology code | Formation | Color | Grain size | Texture | Weathering | Hardness | Fractures | Joint angle | Bedding angle | Foliation | Faults | Veins | Shear zone | Mineral | Mineral % | Mineralization style | Sulphide % | Alteration | Alteration intensity | Sample type | Laboratory | Batch | Assay status | Rock strength | Joint condition | Joint spacing | Roughness | Infilling | Water condition | Description / remarks | Action |
|---|
Export and Report Options
Core Sample Logging Guide
Core sample logging records geological observations from drilled rock intervals. They also describe lithology, structures, alteration, mineralization, and sampling details. Consistent records help teams compare holes across an exploration project. They support geological models, laboratory submissions, and engineering reviews. Clear field descriptions also improve later interpretation and verification.
Why Recovery And RQD Matter
Core recovery compares recovered material against the drilled interval length. High recovery usually indicates most drilled rock reached the core box. Lower recovery can reflect broken ground, soft zones, or drilling losses. RQD provides another practical indicator of rock mass quality. This tool calculates both percentages from the measurements you enter. Review unusual values before using them in technical interpretations.
Logging Lithology And Structures
Lithology entries should use clear rock names and project codes. Record color, grain size, texture, weathering, hardness, and formation. Structural observations can include joints, bedding, foliation, faults, and veins. Shear zones and fracture counts can identify weaker rock sections. Mineralization fields capture minerals, estimated percentages, sulphides, style, and alteration. Use consistent terminology throughout the hole whenever project standards allow.
Sampling And Quality Control
Every laboratory sample should have a unique and traceable identifier. Record sample type, laboratory, batch, and current assay status. Remarks can document duplicates, standards, blanks, controls, or unusual handling. Check sample boundaries against physical markers before submitting the final log. Depth intervals should not overlap unless project procedures require overlap. Gaps should be explained when core loss or missing records occur.
Using The Generated Report
Start by entering project, location, and drill hole information. Add intervals from the shallowest depth toward the hole bottom. Enter recovered core and RQD lengths from measured field observations. Complete geological and sampling fields as information becomes available. Review summary values for missing core and low-quality intervals. Export CSV for databases and detailed spreadsheet analysis. Export PDF for convenient field or office documentation. Final interpretations should follow project standards and professional review.
Example Core Log Data
| Interval | Rock | Recovery | RQD | Mineralization | Interpretation |
|---|---|---|---|---|---|
| 0.0–1.5 m | Weathered granite | 88% | 62% | Trace pyrite | Moderately weathered surface zone |
| 1.5–3.0 m | Granodiorite | 97% | 84% | 1% pyrite | Competent intrusive rock |
| 3.0–4.5 m | Quartz vein zone | 93% | 72% | 3% sulphides | Mineralized veining interval |
| 4.5–6.0 m | Altered granodiorite | 90% | 68% | 2% pyrite | Fractured alteration zone |
Formula Used
Interval length = To depth − From depth
Core recovery (%) = Recovered core length ÷ Interval length × 100
RQD (%) = RQD length ÷ Interval length × 100
Missing core = Interval length − Recovered core length
How to Use This Calculator
- Enter project and drill hole information.
- Add each core interval in drilling order.
- Record recovered core and RQD lengths.
- Add lithology, structure, mineralization, and sampling details.
- Review the summary for quality and completeness.
- Download CSV or PDF for your project records.
Frequently Asked Questions
What is core recovery?
Core recovery measures how much core was recovered compared with the drilled interval. It can highlight lost or highly broken material.
What is RQD?
Rock Quality Designation is a common rock quality indicator based on the amount of sound core meeting the selected length criterion.
Can I log mineralized intervals?
Yes. Each row includes mineral type, percentage, sulphide content, mineralization style, alteration, and alteration intensity.
Can I record laboratory information?
Yes. Sample type, laboratory, batch, sample identifier, and assay status can be stored for each interval.
Does the PDF include every field?
The PDF provides a compact report containing key interval fields. The CSV export contains the complete detailed dataset.
Should this replace professional geological logging?
No. This tool supports data entry and calculations. Final logging standards and interpretations should follow qualified professional review.