Any land annexed to or made a part of the City of Steubenville subsequent to the effective date of this Zoning Code shall immediately be classified as the "R-1A" Low Density Residential District as of the effective date of the annexation. Within one hundred eighty (180) days from the effective date of any annexation, the Planning Commission shall prepare and submit to City Council a "Land Use Plan" of the annexed territory, setting forth its recommendations for the zoning of such lands. The Planning Commission shall hold at least one (1) public hearing thereon before submitting its final report to Council. Following receipt of the final report of the Planning Commission, Council shall amend the Zoning Map in accordance with the procedures prescribed for zoning map amendments in chapter 1191 of this Zoning Code.