Paleolatitudes of Triassic-Jurassic rift basins.  This graph plots age (in millions of years) on the y-axis and present-day latitude (top-axis) of rocks deposited in select rift basins from eastern North America and the Argana basin of Morocco (present-day latitude given in terms of North American coordinates).  The curved gray lines represent paleolatitudes determined from magnetic inclinations. For example, the oldest rocks in the Newark basin accumulated at a paleolatitude of ~0° (the magnetic equator), whereas the youngest rocks accumulated at a paleolatitude of ~10° (left arrow). Note that the oldest (Norian) evaporites (e) in the Argana basin also accumulated at a paleolatitude of 10°, but these rocks are 13 million years older than Newark basin rocks with the same latitude. Thus, at 215 Ma, the Argana basin was located at a 10° latitude (whereas the Newark basin was located at a 7° latitude). At 202 Ma, the Newark basin was located at a 10° latitude, whereas the Argana basin was located at a latitude of 13° (center arrow).  Note that the paleolatitudes for the Fundy and Argana basins are quite similar for similar-aged rocks (e.g., 14° and 13° for basalts that are 202 Ma; middle and right arrows). The Triassic-Jurassic boundary occurs between the Rhaetian and Hettangian stages. From Olsen et al. (2000).