<simpleType name="OrientationObsPropertyEnumType">
  <union>
    <simpleType>
      <restriction base="string">
        <enumeration value="bedding">
          <annotation>
            <documentation>Orientations of bedding: the layering of sediments or sedimentary rock.</documentation>
          </annotation>
        </enumeration>
        <enumeration value="cross-bedding">
          <annotation>
            <documentation>Orientations of cross-bedding: inclined layers within a bed that lie at an angle to the main bedding.</documentation>
          </annotation>
        </enumeration>
        <enumeration value="faults">
          <annotation>
            <documentation>Orientations of faults: fractures formed by tectonic forces (tension, compression or shear), along which the rock on either side has been displaced.</documentation>
          </annotation>
        </enumeration>
        <enumeration value="joints">
          <annotation>
            <documentation>Orientations of joints: fractures formed by tension, cooling or pressure release, along which there has been no appreciable displacement.</documentation>
          </annotation>
        </enumeration>
        <enumeration value="fractures">
          <annotation>
            <documentation>Orientations of fractures: breaks in the rock mass formed by brittle stress. Use for a fracture that is not classified as a joint or a fault; faults show displacement, joints do not.</documentation>
          </annotation>
        </enumeration>
      </restriction>
    </simpleType>
    <simpleType>
      <restriction base="string">
        <pattern value="Other: .{2,}"/>
      </restriction>
    </simpleType>
  </union>
</simpleType>