Western subduction again brings volcanic arcs on margin of US, where Sonoma orogeny spreads upward to BC as Cassiar orogeny continuing through Triassic. Zuni transgression sequence starts. Series of faulted troughs develop Nova Scotia to North Carolina from pre-rifting tensions. Rifts develop from separate domes creating three legged rift faults that join each other. Reactivation of earlier strike- slip faults.
Downfaulted blocks accumulate sediments from mountainous rivers.
Manicouagan meteor impact in Quebec. Iberia rift phase starts 200 Rifting separates East coast from Africa, Atlantic opens at accelerated rate. Several Appalachian shear pulses interlace with volcanic pulses throughout Jurassic and Cretateous. Several shifts in direction and speed of separation. Alternating marine and deltaic deposition builds seaward, mostly becoming shelf.