In reply to:

I believe a continent is defined by whether it's on its own tectonic plate.


As I understand the situation, tectonic plate theory was first put forward in the early part of this century (without wishing to YART I still consider this the 20th century) but did not gain acceptance until the late 1950s or early 1960s. So how were continents defined before then?

Bingley



Bingley