The term "Tertiary" is no longer considered a valid descriptor, although it still appears frequently in literature and outdated materials. The Tertiary period generally includes the time period more-or-less immediately preceding the present (about 2 million years ago) to the time immediately following the extinction of the dinosaurs at the end of the Mesozoic. Since the Tertiary describes a period of over 60 million years, it's impossible to precisely describe the position of the landmasses, but we can generally say that they would have been fairly recognizable if viewed from orbit.
A series of research-supported maps are available in the link below. Starting with the Eocene and ending with the Miocene, you can see that the landmasses are generally the same as they are today, with the exception of a few details, particularly in low-lying areas. For example, Central America did not initially connect North with South, Africa was not connected to Eurasia, large amounts of Russia were flooded, and the Himalayas were in the process of forming.