Any parcel of land with an area or width less than that prescribed for a lot in the zone in which such lot is located, which parcel was under one ownership or control at the date of adoption of this Ordinance, and where the owner thereof owns no adjoining land, may be used as a lot for any purpose permitted in the zone in which it is located, provided that the area of the lot is not less than 1/3 of the zone requirement and the width of said lot is not less than 1/2 of the zone requirement and further provided that all other zone regulations are complied with.