The paper deals with semantics of Russian prepositions. We consider prepositional meaning to be the relation found in prepositional constructions where it should be regarded as a special type of relationship between content words. There is a rather small set of common prepositional meanings that we call syntaxemes after G.A. Zolotova that encompass the larger part of the Russian prepositional semantics as a whole. In this paper we propose a methodology of prepositional phrase extraction and syntaxeme identification based on text corpora and corpus statistics. Prepositional construction meaning is detected automatically using the SemSin parser. We demonstrate our methodology on constructions with the polysemous Russian preposition {greek characters) (through).