. Palaeoenvironmental changes in the Transylvanian Ba sin dur ing the Early Mio cene re vealed by the foraminifera as sem blages. Geo log i cal Quar terly, 60 (1): 167-180, doi: 10.7306/gq.1245The evo lu tion of the Transylvanian Ba sin dur ing the Early Mio cene has been re con structed from the suc ces sion of palaeoenvironments in ferred from sedimentological trends and the suc ces sion of spe cific foraminiferal as sem blages from Lower Mio cene Tihãu sec tion in the north west ern Transylvanian Ba sin. Plank tonic foraminifera sug gest a Burdigalian age and re cord sea level changes, cli ma tic and pro duc tiv ity events. Ben thic foraminifera of fer data on the palaeoenvironmental evo lu tion, with a large-scale progradational (coars en ing up) sed i men tary suc ces sion in flu enced by re gional tec ton ics. The suc ces sion of depositional events in cludes: (1) transgressive coarse grained de pos its with typ i cal Med i ter ra nean as semblages of bi valves in beach en vi ron ments; (2) a glauconitic fa cies which can be as so ci ated with the max i mum flood ing surface of the trans gres sion; (3) sed i men ta tion con tin ued on a nar row shelf in flu enced by del tas dur ing the highstand; (4) the in flu ence of re gional tec ton ics and sub se quent fill ing with turbidites as so ci ated with fan del tas.