Uranium-Series Speleothem Age Calculator
Closed no initial Th 230230 Th/U238 chain inversion includes separately measured present U234 excess, bounded monotone bisection; no detrital/open-system correction or actual dated-age certification. Caller independently establishes sample/context/calibration applicability; not definitive chronology, provenance, taxonomy, disease or human identity.
Description
Uranium-series dating relates activity ratios to decay under a closed-system model.
Uranium-series dating relates activity ratios to decay under a closed-system model.1
Initial thorium, contamination and model branch assumptions affect whether an age solution is meaningful. Use Uranium-Series Speleothem Age Calculator to evaluate the supplied inputs under the model explained below.
When to use Uranium-Series Speleothem Age Calculator
Use Uranium-Series Speleothem Age Calculator to evaluate the supplied inputs under the model explained below. Establish the units, measurement scope and model assumptions before entering values.
How to use Uranium-Series Speleothem Age Calculator and understand its results
- Establish the units, measurement scope and model assumptions before entering values.
- Enter Observed th230 u238 activity ratio, Observed u234 u238 activity ratio, Caller th230 decay per year, Caller u234 decay per year, Caller maximum age years using the field table and validation rules below, then run the tool.
- Read Conditional closed system age years; interpret the units, signs, ordering and unknown-value placeholders described below.
- Correct reported input errors and rerun. Apply successful results according to their specific meanings and check the assumptions before using them in a decision.
| Input field | Meaning | Value type | Requirement |
|---|---|---|---|
| observedTh230U238ActivityRatio | Observed th230 u238 activity ratio | number | Required; constraints below |
| observedU234U238ActivityRatio | Observed u234 u238 activity ratio | number | Required; constraints below |
| callerTh230DecayPerYear | Caller th230 decay per year | number | Required; constraints below |
| callerU234DecayPerYear | Caller u234 decay per year | number | Required; constraints below |
| callerMaximumAgeYears | Caller maximum age years | number | Required; constraints below |
Enter nonnegative observed Th230/U238 activity ratio, observed U234/U238 ratio at least 1, positive decay constants per year with λ230>λ234, and a positive maximum age in years. The monotone model assumes initial Th230=0 and must reach the target within the caller bracket. Bisect [0,maximumAge] for 80 iterations using 1−exp(−λ230t)+(Uratio−1)λ230/(λ230−λ234)×(1−exp(−(λ230−λ234)t)). Return the midpoint in years. No detrital correction, open-system assessment, uncertainty or alternative branch is provided.
age=root of model(t)=observedTh230U238 within [0,callerMaximumAge], using 80 bisections Use the field order, units and branch conditions described above.
| Output field | Meaning | Value type |
|---|---|---|
| conditionalClosedSystemAgeYears | Conditional closed system age years | number |
{
"input": {
"observedTh230U238ActivityRatio": 0.5,
"observedU234U238ActivityRatio": 1,
"callerTh230DecayPerYear": 0.001,
"callerU234DecayPerYear": 0.0001,
"callerMaximumAgeYears": 10000
},
"output": {
"conditionalClosedSystemAgeYears": 693.1471805599451
}
}Limitations and assumptions
Initial thorium, contamination and model branch assumptions affect whether an age solution is meaningful. Apply the exact scope and assumptions explained above.
All listed fields require explicit values. Unexpected fields, incorrect types, nonfinite numbers and sparse arrays fail validation. Domain-specific bounds, alignments and supported tokens are explained above; extremely large inputs or outputs can also be rejected. Input errors differ from successful false results, empty match lists and unknown-evidence placeholders.
Alternative or Complementary methods
Use Potassium-Argon Age Calculator for a related task: Potassium–argon age depends on a radiogenic argon ratio and decay-branch constants.
Use C14 Age From Activity Calculator for a related task: Radiocarbon activity supports an exponential age under a chosen half-life convention.
References
-
Uranium-Series Speleothem Age Calculator — tool.io
Similar or alternative tools
- Potassium-Argon Age Calculator
Potassium–argon age depends on a radiogenic argon ratio and decay-branch constants.
- C14 Age From Activity Calculator
Radiocarbon activity supports an exponential age under a chosen half-life convention.