the Gorda Plate and Explorer Plate. By this time the last of the Kula Plate had been subducted, initiating the Queen Charlotte transform fault on the coast of British Columbia; coastal subduction has been reduced to just the Cascadia Subduction Zone under Oregon and Washington. Newberry Hotspot Track – Brothers Fault Zone The Newberry Hotspot Track – a series of volcanic domes and lava flows closely coincident with the Brothers Fault Zone (BFZ) – is of interest because it is parallel to the OWL. Unlike anything on the OWL, these lava flows can be dated, and they show a westward age progression from an origin at the McDermitt Caldera on the Oregon-Nevada border to the Newberry Volcano. Curiously, the Yellowstone hotspot also appears to have originated in the vicinity of the McDermitt Caldera, and is generally considered to be closely associated with the Newberry magmatism. But while the track of the Yellowstone hotspot across the Snake River Plain conforms to what is expected from the motion of the North American Plate across some sort of "hotspot" fixed in the underlying mantle, the Newberry "hotspot" track is oblique to the motion of the North American Plate; this is inconsistent with the hotspot model. Alternative models include: 1) flow of material from the top layer of the mantle (asthenosphere) around the edge of the Juan de Fuca Plate (a.k.a. "Vancouver slab"), 2) flows reflecting lithospheric topography (such as the edge of the craton), 3) faulting in the lithosphere, or 4) extension of the Basin and Range province (which in turn may be due to interactions between the North American, Pacific, and Farallon Plates, and possibly with the subduction of the triple point where the three plates came together), but none is yet fully accepted. These models generally attempt to account only for the source of the Newberry magmatism, attributing the "track" to pre-existing weakness in the crust. No model yet accounts for the particular orientation of the BFZ, or the parallel Eugene-Denio or Mendocino Fault Zones (see map). Bermuda Hotspot Track? It was noted as early as 1963 that the OWL seems to align with the Kodiak-Bowie Seamount chain. A 1983 paper by Morgan suggested that this seamount—OWL alignment marks the passage some 150 Ma ago of the Bermuda hotspot. (This same passage has also been invoked to explain the Mississippi Embayment. However, substantial doubt has been raised as to whether Bermuda