|
Although the network is not sufficiently dense to accurately determine earthquake focal depths, it can be assumed that the active zone lies in the mid- to upper crust, between 5 and 25 km depth, similar to the Charlevoix Seismic Zone (CSZ). From some focal mechanism determinations (see references below) and by analogy with the CSZ, most earthquakes probably cluster along or between the mapped Iapetan faults (also called St. Lawrence paleo-rift faults), beneath the Logan's line and the Appalachians.
|