Mg/Ca Paleothermometry
Invert caller Mg/Ca=A exp(B T_C) with calibration-domain guard and ratio-only uncertainty; units/taxon/calcification-depth and dissolution effects remain explicit external assumptions.
Description
An exponential Mg/Ca calibration relates a measured ratio to calcification temperature.
An exponential Mg/Ca calibration relates a measured ratio to calcification temperature. Taxon and measurement units determine which calibration applies.
Invert caller Mg/Ca=A exp(B T_C) with calibration-domain guard and ratio-only uncertainty; units/taxon/calcification-depth and dissolution effects remain explicit external assumptions.
When to use Mg/Ca Paleothermometry
Use this tool to invert caller Mg/Ca=A exp(B T_C) with calibration-domain guard and ratio-only uncertainty; units/taxon/calcification-depth and dissolution effects remain explicit external assumptions.
Prepare the fossil measurements or occurrence records and the chosen calibration parameters. Retain the stated coordinate, age and measurement conventions.
How to use Mg/Ca Paleothermometry and understand its results
- Prepare the fossil measurements or occurrence records and the chosen calibration parameters. Retain the stated coordinate, age and measurement conventions.
- Enter measuredMgCaRatio, exponentialCalibrationScale, exponentialTemperatureSlopePerC, calibrationTemperatureBoundsC, ratioSigma using the field table and calculation rules, then run the tool.
- Read modelTemperatureC, measurementTemperatureSigmaC. 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 |
|---|---|---|---|
| measuredMgCaRatio | Measured mg ca ratio | number | Required |
| exponentialCalibrationScale | Exponential calibration scale | number | Required |
| exponentialTemperatureSlopePerC | Exponential temperature slope per c | number | Required |
| calibrationTemperatureBoundsC | Calibration temperature bounds c | list of number | Required |
| ratioSigma | Ratio sigma | number | Required |
Use positive ratio, scale and slope, nonnegative ratio sigma and two ordered calibration bounds. Reject temperatures outside the inclusive Celsius domain; report ratio-only propagated uncertainty.1
temperature °C = ln(ratio/scale)/slope; measurement sigma = ratio sigma/(ratio × slope) Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| modelTemperatureC | Model temperature c | number |
| measurementTemperatureSigmaC | Measurement temperature sigma c | number |
{
"input": {
"measuredMgCaRatio": 7.38905609893065,
"exponentialCalibrationScale": 1,
"exponentialTemperatureSlopePerC": 0.1,
"calibrationTemperatureBoundsC": [
0,
30
],
"ratioSigma": 0.1
},
"output": {
"modelTemperatureC": 20,
"measurementTemperatureSigmaC": 0.13533528323661267
}
}Limitations and assumptions
Calibration, dissolution and depth effects remain external; the sigma excludes coefficient uncertainty.
Numbers and computed results must be finite; overflow produces an error. 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 Clumped Isotope Temperature: Invert a supplied Δ47=A/T_K²+B calibration only within caller temperature/reference-frame bounds; no universal isotope coefficients, diagenesis correction or validated paleotemperature. For a complementary task, use Planktonic-Benthic Ratio Productivity Proxy: Correct planktic/benthic observed test counts for caller differential recovery and screen a ratio band; ratio is not a unique productivity or water-depth estimator.
References
-
Mg/Ca Paleothermometry — tool.io
Similar or alternative tools
- Clumped Isotope Temperature
Invert a supplied Δ47=A/T_K²+B calibration only within caller temperature/reference-frame bounds; no universal isotope coefficients, diagenesis correction or validated paleotemperature.
- Planktonic-Benthic Ratio Productivity Proxy
Correct planktic/benthic observed test counts for caller differential recovery and screen a ratio band; ratio is not a unique productivity or water-depth estimator.