If two or more abutting lawfully established nonconforming lots in single ownership, which are located in the REA-120, RA-65, RS-40, and RU-20 Zoning Districts, do not meet all or part of the requirements established for lot frontage, width or area, said lots shall be deemed to be merged and shall be considered as an individual lot and no portion of said lot shall be used or sold in a manner which diminishes compliance with lot width, frontage and area requirements established by this chapter, nor shall any division of any parcel be made which creates a lot with frontage or area below requirements stated in this chapter.