How to map lithostratigraphic descriptions and other units

[hollyel]

This thread is being created to document ongoing questions and discussions around expanded lithostratigraphic information (along with #39 ).

DwC currently has terms for Group, Formation, Member, and Bed. There is often further information that could/should be shared in addition to those terms, but this data can be challenging to represent in existing standards (e.g. other units, informal units, further details for the lithology, or stratigraphic descriptions). Are there suggestions for how to better utilize existing terms for this information? Are new terms needed? Does ABCDEFG have better solutions? If so, what are the options for utilizing these solutions within DwC implementations?

[hollyel]

Comments from paleo-data discussion:

From Kesler Randall: We have a lot of informal members for San Diego region rock units that we use locally. It would be great to have another sub-formation Darwin Core field besides Member and Bed. In addition to lithostratigrahic name fields in Specify, we also have fairly detailed and lengthy descriptions of the lithology of the bed the fossils were recovered from, as well as generalized stratigraphic description of the outcroping/exposure that contained the fossil-producing horizon. We've been recording this type of data for 30 years in a locality description field which we've recently mapped to locationRemarks in Dawin Core. Our department researchers find this stratigraphic contextual information extremely valuable. I guess ideally this kind of data is better placed in a geologicalContextRemarks field - if it existed.

[falkogloeckler]

In ABCD Extension for Geoscience (ABCD-EFG) your can find the terms: Supergroup, Group, Formation, Member, Bed (see: http://www.geocase.eu/sites/default/documentation/html/efg.html#element_LithostratigraphicAttribution_Link0303E5D8)
But additionally also "InformalLithostratigraphicName" and "StratigraphicMeasurmentsOrFacts" (http://www.geocase.eu/sites/default/documentation/html/efg.html#element_StratigraphicMeasurementsOrFacts_Link0304E3A0).
The latter can be used as kind of key-value element (complex type) as documented in ABCD (https://terms.tdwg.org/wiki/abcd2:Unit-MeasurementOrFactAtomised)

So the measured parameter would be "sub-formation" (or however you would like to call the key here) and the value would be accommodated in "lowerValue".
Advantage: it is a very gerneric approach.
Disadvantage: without a controlled vocabulary for the parameters' name aggregating data would be difficult as every institution could have individual terms.