The scope note of A8 Stratigraphic Unit

The ArSol mappings to CIDOC CRM extensions point out the need for reviewing the scope note of the entity A8 Stratigraphic Unit, since It uses the sub-classes of the entity to define it. The proposal is the current scope (1.4.1) note to be changed 

FROM

A8 Stratigraphic Unit

Subclass of:  S20 Physical Feature

Scope Note:  This class comprises S20 Physical Features that are either A2 Stratigraphic Volume Units or A3 Stratigraphic Interfaces
Examples:
The excavator declared the post holes [7] and [8] in Figure 4 to be part of one building

Properties:
AP11 has physical relation (is physical relation of): A8 Stratigraphic Unit

AP15 is or contains remains of (is or has remains contained in): E18 Physical Thing

Proposed scope note

This class comprises S20 Physical Features which appear as the result of a stratigraphic genesis event or process. The internal continuity and the boundaries of an instance of A8 Stratigraphic Unit should be of a kind that can be attributed to a single genesis event or process and have the potential to be observed. One genesis event may have created more than one SU. An instance of A8 Stratigraphic Unit is regarded to exist as long as a part of its matter is still in place with respect to a surrounding reference space such that its spatial features can be associated with effects of the genesis process of interest. Normally at least one of the surfaces (such as the lower one) from its genesis event will remain during its existence.
This also implies that a certain degree of coherent (“conformal”) deformation is tolerable within its time-span of existence. Therefore the place an instance of A8 Stratigraphic Unit occupies can be uniquely identified with respect to the surrounding reference space of archaeological interest.
An instance of A8 Stratigraphic Unit may contain physical objects

Lida Charami, Heraklio 29/7/2016