Description
minimumGap = underlyingYoung-overlyingOld; maximumGap = underlyingOld-overlyingYoung; midpointGap is the difference of interval midpoints.
Geological records use depth datums, age-before-present coordinates and recovery definitions. A signed difference or recovered-length ratio can expose a supplied inconsistency without reconstructing geological history or correcting sample loss.
minimumGap = underlyingYoung-overlyingOld; maximumGap = underlyingOld-overlyingYoung; midpointGap is the difference of interval midpoints.
When to use this tool
Use Unconformity Duration Explicit Bounds when checking an explicit geological coordinate, interval or recovery convention.
How to use the tool and how it works
- Enter overlyingYoung, overlyingOld, underlyingYoung, underlyingOld. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read minimumGap, maximumGap, midpointGap, certainlyPositive. Inspect certainlyPositive before interpreting the associated values.
Require each nonnegative age interval ordered young <= old. minimumGap = underlyingYoung-overlyingOld; maximumGap = underlyingOld-overlyingYoung; midpointGap is the difference of interval midpoints. certainlyPositive uses underlyingYoung > overlyingOld.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| overlyingYoung | Overlying Young | Required. Finite number; minimum 0. |
| overlyingOld | Overlying Old | Required. Finite number. |
| underlyingYoung | Underlying Young | Required. Finite number; minimum 0. |
| underlyingOld | Underlying Old | Required. Finite number. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| minimumGap | Minimum Gap | Required. Finite number. |
| maximumGap | Maximum Gap | Required. Finite number. |
| midpointGap | Midpoint Gap | Required. Finite number. |
| certainlyPositive | Certainly Positive | Required. Boolean. |
{
"input": {
"overlyingYoung": 10,
"overlyingOld": 12,
"underlyingYoung": 20,
"underlyingOld": 24
},
"output": {
"minimumGap": 8,
"maximumGap": 14,
"midpointGap": 11,
"certainlyPositive": true
}
}Limitations and assumptions
- All ages are before-present coordinates on one unit basis. Negative gaps are retained and bounds are supplied extremes, not confidence limits or proof of an unconformity.
- Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Use verified datums, original logs and appropriate geological interpretation when correlating units or reconstructing missing intervals.
References
Similar or alternative tools
- Geological Age Boundary Distance
signedDistance = age-boundary; olderThanBoundary uses strict greater-than.
- Geologic Age Older Younger Pair
Compare explicit compatible ages measured before a common present without assigning geologic periods.