Isotopic Weaning Age Enamel

Locate a unique caller isotopic-enrichment transition on supplied enamel formation ages, excluding enamel maturation lag/other diet effects; proxy timing is not a confirmed age at cessation of breastfeeding.

Description

An enamel isotope transition can be placed on a supplied formation-age curve.

An enamel isotope transition can be placed on a supplied formation-age curve. Its threshold crossing is a timing proxy and need not coincide with the end of breastfeeding.^[1]

When to use Isotopic Weaning Age Enamel

Use this tool to locate a unique caller isotopic-enrichment transition on supplied enamel formation ages, excluding enamel maturation lag/other diet effects; proxy timing is not a confirmed age at cessation of breastfeeding.

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 Isotopic Weaning Age Enamel 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 enamelFormationAgesYears, delta15NValues, postWeaningReferenceDelta15N, callerResidualEnrichmentCriterion using the field table and calculation rules, then run the tool.
Read modelIsotopicTransitionAgeYears. 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
enamelFormationAgesYears	Enamel formation ages years	list of number	Required
delta15NValues	Delta15 n values	list of number	Required
postWeaningReferenceDelta15N	Post weaning reference delta15 n	number	Required
callerResidualEnrichmentCriterion	Caller residual enrichment criterion	number	Required

Supply at least two strictly increasing nonnegative enamel formation ages in years, aligned isotope values, a finite reference and a nonnegative residual criterion. Locate exactly one bracketed crossing by linear interpolation, also accepting a unique exact sample tie. Missing, multiple or plateau crossings are rejected rather than extrapolated.

find age where δ15N(age)−postWeaningReference = residual criterion

Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.

Output field	Meaning	Value type
modelIsotopicTransitionAgeYears	Model isotopic transition age years	number

json

{
  "input": {
    "enamelFormationAgesYears": [
      0,
      1,
      2,
      3
    ],
    "delta15NValues": [
      10,
      9,
      7,
      6
    ],
    "postWeaningReferenceDelta15N": 6,
    "callerResidualEnrichmentCriterion": 2
  },
  "output": {
    "modelIsotopicTransitionAgeYears": 1.5
  }
}

Limitations and assumptions

Formation ages and isotope attribution are supplied. Enamel maturation lag, dietary changes and uncertain baselines are excluded. The result is not a confirmed weaning age or clinical assessment.

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 Delta15N Trophic Level Scale: Evaluate caller nitrogen-enrichment trophic proxy with independent measurement/baseline uncertainty; signed relative positions remain and baseline/enrichment differences are not dietary diagnosis. 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

Isotopic Weaning Age Enamel — tool.io

Similar or alternative tools

Delta15N Trophic Level Scale
Evaluate caller nitrogen-enrichment trophic proxy with independent measurement/baseline uncertainty; signed relative positions remain and baseline/enrichment differences are not dietary diagnosis.
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.