Before acting upon a proposed amendment, the Board of Supervisors shall, as required by law, hold a public hearing thereon. Public notice of such hearing is required and shall contain a brief summary of the proposed amendment and reference to the place where copies of the same can be examined, and shall be published in accordance with the provisions of the Pennsylvania Municipalities Planning Code. If the proposed amendment involves a change to the Zoning Map, notice of the public hearing shall be posted at the affected tract in accordance with Section 609 of the Planning Code at least one week prior to the date of the hearing.