Dear all This is a small step for the CRM (maybe a leap for CRMarcheo) In CRMarcheo there are two classes used to model creation and modification of stratigraphic objects (layers and surfaces), A4 Stratigraphic Genesis and A5 Stratigraphic Modification. A4 is a subclass of A4. The rationale is that in CRMbase and CRMsci modification is seen as a wider concept than creation since all creation involve a modification (of something yet not identifiable). We have had som discussion about the scope not of A5 which does not correpsond to the scope note of S18 and E11 Modification. We are aware that an instance of E11 Modification requires an actor while instances of S18 and A5 don't.
S18 Alteration: This class comprises natural events or man-made processes that create, alter or change physical things, by affecting permanently their form or consistency without changing their identity. Examples include alterations on depositional features-layers by natural factors or disturbance by roots or insects, organic alterations, petrification, etc. E11 Modification [...] Since the distinction between modification and production is not always clear, modification is regarded as the more generally applicable concept. This implies that some items may be consumed or destroyed in an instance of E11 Modification, and that others may be produced as a result of it. [...} Proposal: Change the scope note of A5 from the existing: A5 Stratigraphic Modification Subclass of: S18 Alteration Scope Note: This class comprises activities or processes resulting in the modification of Stratigraphic Units after their genesis through A4 Stratigraphic Genesis Events. to the following: A5 Stratigraphic Modification Subclass of: S18 Alteration? Scope Note: This class comprises activities or processes that create, alter or change instances of A8 Stratigraphic Unit. Since the distinction between stratigrafic modification and stratigraphic creation is not always clear, stratigrafic modification is regarded as the more generally applicable concept. This implies that some items may be consumed or destroyed in an instance of A5 Stratigraphic Modification?, and that others may be produced as a result of it.
