Drill Log

The Drill Log tab allows you to import a vertical isotopic profile from core sampling or drilling, visualize it as a three-track log, and automatically detect isotopic anomalies signaling levels of geochemical interest.

When to Use This Tool?

You have measured an isotopic system (δ34S, δ13C, δ18O…) on core samples at regular intervals.
You are looking for isotopic signature breaks corresponding to lithological contacts, mineralized faults, or alteration levels.
You want to correlate isotopic anomalies with a lithological column.

Expected CSV File Format

The file must contain at least one depth column and one isotopic value column. Headers can be in French or English—the module detects them automatically.

Column	Recognized Headers	Required
Depth	depth, profondeur, prof, depth_m	Yes - in meters
Isotopic Value	delta34S, d34S, delta13C, value, valeur	Yes
Lithology	litho, lithologie, rock, roche	No - Track 3 if present
Uncertainty	sigma, uncertainty, incertitude, err	No - error bars if present

Depths in meters only. Decimal values accept either dots or commas. Rows without an isotopic value are ignored without error. Non-uniform depth intervals are accepted; the log adapts the vertical scale automatically.

Example of a Valid File

depth,delta34S,lithology,uncertainty
12.5,-2.1,Sandstone,0.15
25.0,-1.8,Sandstone,0.12
38.5,+4.7,Mineralized Breccia,0.20
51.0,+11.2,Quartz Vein,0.18
64.5,+3.1,Limestone,0.14
77.0,-0.9,Limestone,0.11

Importing the File

Drill Log Tab → Import CSV → Select File

The module displays a column detection summary. Verify that depth and isotopic value are correctly identified before validating.

The Three-Track Vertical Log

Track	Content
Track 1 - Depth	Vertical scale in meters, from the top to the bottom of the drill core.
Track 2 - Isotopic Value	Continuous curve. Anomalies (> 2σ between consecutive points) are highlighted in red with their σ amplitude annotated.
Track 3 - Lithology	Text column based on the lithology field if present. Empty otherwise.

Anomaly Detection

The module calculates the global standard deviation of the profile (global σ) and then detects every jump between consecutive points exceeding 2 × σ. Anomalies are listed in the summary below the log.

Interpreting Anomalies by Measured System

System	Positive Jump (Sharp Increase)	Negative Jump (Sharp Decrease)
δ34S	Entering a hydrothermal zone - magmatic sulfides or TSR. Proximal signal.	Increased BSR contribution - diagenetic zone or distance from source.
δ13C	¹³C enrichment - hydrothermal carbonate or secondary oxidation.	Depletion - immature organic matter or incoming biogenic methane.
δ18O	Cold meteoric fluid or late low-temperature alteration.	High-temperature precipitation or exchange with a hot hydrothermal fluid (typical of skarns).
δ7Li	⁷Li enrichment - active fractionation by clays, fluid depleted in light Li.	⁶Li enrichment - mantle source or minimally modified fluid.

Cross-reference detected anomalies with the lithological column. An isotopic jump coinciding with a lithology change (e.g., limestone → mineralized breccia) is a strong signal of a mineralized contact or fault.

Statistical Summary Displayed After Import

Number of valid measurement points imported.
Depth range covered (min m / max m).
Mean isotopic value, global standard deviation, and range (min / max).
Number of anomalies detected (> 2σ between consecutive points) and a list with depth + amplitude.