‘X zài Y shàngbiān’ (X is on top of Y) (e.g., qiú zài zhuōzi shàngbiān) (The ball is on top of the table): The compound position noun ‘Y shàngbiān’ (the top of Y) refers to the top surface of the reference object or to the domain/space extended over the top surface of the reference object, hence ‘X zài Y shàngbiān’ allows two interpretations: one is coincidence or contact, that is, the located object is on the top of the reference object, it has contact with and is supported by the reference object. The other interpretation is that the located object occupies a position in the space extended upward from the top surface of the reference object. In this interpretation, ‘X zài Y shàngbiān’ expresses the spatial relation of superiority. Superiority involves the space higher than the highest point of the reference object.
 Loar, J. K. (2011). Chinese syntactic grammar: functional and conceptual principles. New York: Peter Lang.