Strontium Isotope Provenance Ratio Tool
Compare measured strontium ratio to all caller source baselines with independent sigma, retaining overlap and no matches; no ratio aliases, geographic identification or forced provenance.
Description
Strontium isotope provenance screening compares a measured ratio with multiple reference baselines.
Strontium isotope provenance screening compares a measured ratio with multiple reference baselines. Uncertainty can make several sources compatible, and preserving that overlap avoids a forced geographic assignment.1
Compare measured strontium ratio to all caller source baselines with independent sigma, retaining overlap and no matches; no ratio aliases, geographic identification or forced provenance.
When to use Strontium Isotope Provenance Ratio Tool
Use this tool to compare measured strontium ratio to all caller source baselines with independent sigma, retaining overlap and no matches; no ratio aliases, geographic identification or forced provenance.
Prepare the artifact, site or survey measurements and any independently established calibration or model choices. Keep paired observations aligned and confirm units and coordinate conventions.
How to use Strontium Isotope Provenance Ratio Tool and understand its results
- Prepare the artifact, site or survey measurements and any independently established calibration or model choices. Keep paired observations aligned and confirm units and coordinate conventions.
- Enter sampleSr87Sr86Ratio, sampleSigma, sourceMeanRatios, sourceSigmas, callerAbsoluteZLimit using the field table and calculation rules, then run the tool.
- Read sourceStandardizedDifferences, compatibleSourceFlags, compatibleSourceCount. The explanation below defines the units, signs, ordering and any flags or placeholder values.
- If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.
| Input field | Meaning | Value type; see rules below | Requirement |
|---|---|---|---|
| sampleSr87Sr86Ratio | Sample sr87 sr86 ratio | number | Required |
| sampleSigma | Sample sigma | number | Required |
| sourceMeanRatios | Source mean ratios | list of number | Required |
| sourceSigmas | Source sigmas | list of number | Required |
| callerAbsoluteZLimit | Caller absolute z limit | number | Required |
Enter a positive sample 87Sr/86Sr ratio, positive source means, nonnegative independent sigmas and a positive absolute-z limit. Each combined sigma must be positive. Return signed standardized differences, inclusive compatibility flags and the number of compatible sources. Zero or multiple matches are retained.
Paired lists must be nonempty and have equal lengths.
z_i = (sampleRatio−sourceMean_i)/hypot(sampleSigma,sourceSigma_i); compatible = |z_i|≤limit Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| sourceStandardizedDifferences | Source standardized differences | list of number |
| compatibleSourceFlags | Compatible source flags | list of number |
| compatibleSourceCount | Compatible source count | number |
{
"input": {
"sampleSr87Sr86Ratio": 0.71,
"sampleSigma": 0.001,
"sourceMeanRatios": [
0.71,
0.714
],
"sourceSigmas": [
0.001,
0.001
],
"callerAbsoluteZLimit": 2
},
"output": {
"sourceStandardizedDifferences": [
0,
-2.828427124746192
],
"compatibleSourceFlags": [
1,
0
],
"compatibleSourceCount": 1
}
}Limitations and assumptions
Baselines and the screening limit are supplied. Independent normal-scale uncertainties are assumed, and one isotope ratio does not uniquely identify birthplace, migration or source geography.
Numeric inputs must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Numeric lists are limited to 100,000 entries; the rules above may require smaller limits. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.
Alternative or Complementary methods
Use Lead Isotope Ratio Source Tool: Screen all caller lead-source multivariate baselines using reused Mahalanobis distance and combined covariance; retains ambiguous/no matches, without simple ratio aliases or source identification. For a complementary task, use Oxygen Isotope Migration Proxy Tool: Apply caller enamel-to-water isotope calibration and compare a local baseline with independent uncertainty; differing isotope state is not proof of migration, birthplace or ancestry.
References
-
Strontium Isotope Provenance Ratio Tool — tool.io
Similar or alternative tools
- Lead Isotope Ratio Source Tool
Screen all caller lead-source multivariate baselines using reused Mahalanobis distance and combined covariance; retains ambiguous/no matches, without simple ratio aliases or source identification.
- Oxygen Isotope Migration Proxy Tool
Apply caller enamel-to-water isotope calibration and compare a local baseline with independent uncertainty; differing isotope state is not proof of migration, birthplace or ancestry.