geoTime.xsd Components that describe geological time scales and stratigraphic charts. Copyright (c) 2005 CSIRO - see https://www.seegrid.csiro.au/twiki/bin/view/Xmml/LegalNotices#Software_Notice List boundary objects so that they may be used by-reference in the description of eras In an ordinal reference system the order of events in time can be well established, but the magnitude of the intervals between them can not be accurately determined (e.g. a stratigraphic sequence). Replacement for GML TimeOrdinalReferenceSystem in which the content model for TimeOrdinalEra is modified. Replacement for GML TimeOrdinalEra in which the limits are described by TimeOrdinalEraBoundary objects. Note that in this schema the limits of a Time Ordinal Era are "Boundary" objects. This is a variation from ISO 19108 in which limits are given as time positions. This is in order to fulfill the requirements of ordinal reference systems based on eras delimited by named points or nodes, which are common in geology, archeology, etc. This change is subject of a change proposal to ISO An Era may be composed of several member Eras. The "member" element implements the association to the Era at the next level down the hierarchy. "member" follows the standard GML property pattern whereby its (complex) value may be either described fully inline, or may be the target of a link carried on the member element and described fully elsewhere, either in the same document or from another service. In a particular Time System, an Era may be a member of a group. The "group" element implements the back-pointer to the Era at the next level up in the hierarchy. If the hierarchy is represented by describing the nested components fully in the their nested position inside "member" elements, then the parent can be easily inferred, so the group property is unnecessary. However, if the hierarchy is represented by links carried on the "member" property elements, pointing to Eras described fully elsewhere, then it may be useful for a child (member) era to carry an explicit pointer back to its parent (group) Era. Replacement for GML TimeOrdinalEra in which the limits are described by TimeOrdinalEraBoundary objects. A Boundary object is used to describe the limits of an Era. This is patterned after TimeNode. This change is subject of a change proposal to ISO An extension of the GML TimeOrdinalEra, with an additional "rank" and "stratotype" properties. not mandatory since unit stratotypes are no longer recommended An extension of the GML TimeOrdinalEraBoundary, with an additional "event" and "stratotype" properties. An extension of the GML TimeOrdinalEraBoundary, with an additional status property. A stratigraphic event. Use the description property to record a detailed description of the nature of the event A stratigraphic event. A special Feature used in stratigraphy A special Feature used in stratigraphy An observation resulting in an estimate of the age of the subject. An observation resulting in an estimate of a time position. This can be a geochron measurement, or an estimate made using less precise techniques.