Pset_GeoObsCommon Common properties for geoscience observations. IfcGeoScienceObservation IfcBorehole IfcSensor IfcSpatialZone/MAPPEDZONE IfcSpatialZone/TESTEDZONE IfcGeoScienceObservation,IfcBorehole,IfcSensor,IfcSpatialZone/MAPPEDZONE,IfcSpatialZone/TESTEDZONE ObservationStartDate Start date when the observation was made. ObservationEndDate End date when the observation was made. Lithology Defines all natural materials resulting from the combination of minerals, particles or biogenic elements.