Upon a petition signed by not less than three-fourths of the qualified electors and by the owners of not less than three-fourths in assessed value of the property in any territory within the limits of an incorporated municipality and contiguous or adjacent to such limits, the governing body of the municipality, by ordinance, may in its discretion, disconnect and exclude such territory from the municipality. This section, however, applies only to lands that have not been platted under either sections 40-50.1-01 through 40-50.1-17 or section 57-02-39, and where no municipal improvements have been made or constructed therein or adjacent thereto. Further, in the event any property for which exclusion is petitioned has been within the limits of an incorporated municipality for more than ten years prior thereto and, as of the time of filing the    petition, is not platted and has no municipal improvements thereon, the governing body of the municipality may disconnect and exclude such territory by ordinance from the municipality.