Lands which for reason of law, change in ownership or for any other reason, come under the authority of the Town of Fountain Hills after this Ordinance becomes effective and which have not been zoned prior thereto by any other jurisdiction having zoning authority, shall be subject to the regulations of the R1-43 Zoning District until such time as soon as practicable thereafter public hearings are held as required by law for the expressed purpose of zoning such lands pursuant to this Ordinance.