Stratum Depth Interpolation

Interpolate a supplied monotone stratigraphic depth-age model within bracketed control points; no extrapolation, reversals, hiatus uncertainty or sedimentation-rate inference.

Description

A monotone depth–age model interpolates between established stratigraphic controls.

A monotone depth–age model interpolates between established stratigraphic controls. Bracketed interpolation avoids silently inventing ages outside the dated profile.^[1]

Interpolate a supplied monotone stratigraphic depth-age model within bracketed control points; no extrapolation, reversals, hiatus uncertainty or sedimentation-rate inference.

When to use Stratum Depth Interpolation

Use this tool to interpolate a supplied monotone stratigraphic depth-age model within bracketed control points; no extrapolation, reversals, hiatus uncertainty or sedimentation-rate inference.

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 Stratum Depth Interpolation 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 controlDepthsM, controlCalendarAgesBp, sampleDepthsM using the field table and calculation rules, then run the tool.
Read interpolatedCalendarAgesBp. 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
controlDepthsM	Control depths m	list of number	Required
controlCalendarAgesBp	Control calendar ages bp	list of number	Required
sampleDepthsM	Sample depths m	list of number	Required

Supply nonnegative control and sample depths in m and at least two strictly increasing calendar ages BP. For each requested depth, require aligned strictly increasing control depths and a query within their inclusive range. Return linearly interpolated ages in sample order. An empty sample list returns an empty result.

Each sequence checked for increasing order must contain at least two strictly increasing values.

age(d) = age_left + (age_right−age_left)(d−depth_left)/(depth_right−depth_left)

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

Output field	Meaning	Value type
interpolatedCalendarAgesBp	Interpolated calendar ages bp	list of number

json

{
  "input": {
    "controlDepthsM": [
      0,
      1,
      3
    ],
    "controlCalendarAgesBp": [
      100,
      200,
      600
    ],
    "sampleDepthsM": [
      0.5,
      2
    ]
  },
  "output": {
    "interpolatedCalendarAgesBp": [
      150,
      400
    ]
  }
}

Limitations and assumptions

The supplied controls define the age model. Extrapolation is rejected for requested samples; hiatuses, reversals and control-age uncertainty are not modeled. BP must use the caller's consistent reference convention.

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 OSL Age: Infer residual-corrected OSL age with independent dose/rate uncertainties, retaining signed residual nondetections; assumes full resetting and constant effective dose rate, not a validated burial age. For a complementary task, use Calibrated Age Intercept Range: Intersect a measured radiocarbon uncertainty band with a supplied piecewise-linear calibration curve, retaining disjoint intervals; not Bayesian calibration, curve uncertainty or an embedded IntCal lookup.

References

Stratum Depth Interpolation — tool.io

Similar or alternative tools

OSL Age
Infer residual-corrected OSL age with independent dose/rate uncertainties, retaining signed residual nondetections; assumes full resetting and constant effective dose rate, not a validated burial age.
Calibrated Age Intercept Range
Intersect a measured radiocarbon uncertainty band with a supplied piecewise-linear calibration curve, retaining disjoint intervals; not Bayesian calibration, curve uncertainty or an embedded IntCal lookup.