Class <<FeatureType>> GeologicUnit (extends GeologicFeature )

<xs:element xmlns:xs="http://www.w3.org/2001/XMLSchema" name="GeologicUnit" substitutionGroup="gsml:GeologicFeature" type="gsml:GeologicUnitType">
    <xs:annotation>
        <xs:documentation>Operationally, the GeologicUnit element is a container used to associate geologic properties with some mapped occurrence (through GeologicFeature.occurrence -&gt; MappedFeature link), or with a geologic unit ControlledConcept in a vocabulary (through the GeologicUnit.classifier -&gt;ControlledConcept link).

Conceptually, may represent a body of material in the Earth whose complete and precise extent is inferred to exist (NADM GeologicUnit, Stratigraphic unit in sense of NACSN or Intnl Stratigraphic Code), or a classifier used to characterize parts of the Earth (e.g. lithologic map unit like 'granitic rock' or 'alluvial deposit', surficial units like 'till' or 'old alluvium').

Spatial properties are only available through association with a MappedFeature. Includes both formal units (i.e. formally adopted and named in the official lexicon) and informal units (i.e. named but not promoted to the lexicon) and unnamed units (i.e. recognisable and described and delineable in the field but not otherwise formalised). 

Will be made Abstract when a complete (enough) set of specialized subtypes is defined.</xs:documentation>
    </xs:annotation>
</xs:element>

<xs:complexType xmlns:xs="http://www.w3.org/2001/XMLSchema" name="GeologicUnitType">
    <xs:complexContent>
        <xs:extension base="gsml:GeologicFeatureType">
            <xs:sequence>
                <xs:element maxOccurs="unbounded" minOccurs="0" name="bodyMorphology" type="gsml:CGI_TermValuePropertyType">
                    <xs:annotation>
                        <xs:documentation>The geometry or form of a GeologicUnit.  Examples include: dike (dyke), cone, fan, sheet, etc. Morphology is independent of the substance (EarthMaterial) that composes the GeologicUnit.</xs:documentation>
                    </xs:annotation>
                </xs:element>
                <xs:element maxOccurs="1" minOccurs="0" name="compositionCategory" type="gsml:CGI_TermValuePropertyType">
                    <xs:annotation>
                        <xs:documentation>Term to specify the gross chemical character of geologic unit. 
Examples: silicate, carbonate, ferromagnesian, oxide.  
Chemical classification terms for igneous rocks also go here.
Examples: alkalic, subaluminous, peraluminous, mafic, felsic, intermediate.</xs:documentation>
                    </xs:annotation>
                </xs:element>
                <xs:element maxOccurs="unbounded" minOccurs="0" name="exposureColor" type="gsml:CGI_TermValuePropertyType">
                    <xs:annotation>
                        <xs:documentation>Typical color at the outcrop of a geologic unit.</xs:documentation>
                    </xs:annotation>
                </xs:element>
                <xs:element maxOccurs="unbounded" minOccurs="0" name="outcropCharacter" type="gsml:CGI_TermValuePropertyType">
                    <xs:annotation>
                        <xs:documentation>Describes the nature of outcrops formed by a geologic unit.   Examples: bouldery, cliff-forming, ledge-forming, slope-forming, poorly exposed</xs:documentation>
                    </xs:annotation>
                </xs:element>
                <xs:element maxOccurs="1" minOccurs="0" name="rank" type="cgu:CodeWithAuthorityType">
                    <xs:annotation>
                        <xs:documentation>Term that classifies the geologic unit in a generalization hierarchy from most local/smallest volume to most regional. Scoped name because classification is asserted, not based on observational data.
Examples: group, subgroup, formation, member, bed, intrusion, complex, batholith</xs:documentation>
                    </xs:annotation>
                </xs:element>
                <xs:element maxOccurs="1" minOccurs="0" name="classifier" type="gsml:ControlledConceptPropertyType"/>
                <xs:element maxOccurs="unbounded" minOccurs="0" name="composition" type="gsml:CompositionPartPropertyType"/>
                <xs:element maxOccurs="1" minOccurs="0" name="metamorphicCharacter" type="gsml:MetamorphicDescriptionPropertyType"/>
                <xs:element maxOccurs="unbounded" minOccurs="0" name="part" type="gsml:GeologicUnitPartPropertyType"/>
                <xs:element maxOccurs="unbounded" minOccurs="0" name="physicalProperty" type="gsml:PhysicalDescriptionPropertyType"/>
                <xs:element maxOccurs="1" minOccurs="0" name="weatheringCharacter" type="gsml:WeatheringDescriptionPropertyType"/>
            </xs:sequence>
        </xs:extension>
    </xs:complexContent>
</xs:complexType>

<xs:complexType xmlns:xs="http://www.w3.org/2001/XMLSchema" name="GeologicUnitPropertyType">
    <xs:sequence minOccurs="0">
        <xs:element ref="gsml:GeologicUnit"/>
    </xs:sequence>
    <xs:attributeGroup ref="gml:AssociationAttributeGroup"/>
</xs:complexType>