 These volcanic plugs form a northwest trend about inland from the Pemberton and Garibaldi volcanic belts and exist along the axis of the volcanic plateau.Silicic tuff lying between Chilcotin basalt lava flows, likely originated from explosive eruptions related to arc volcanism in the Garibaldi and Pemberton belts just to the west and was preserved between successive basaltic lava eruptions in the Chilcotin back-arc basin.It is suggested by geoscientists the Chilcotin Group forms a sequence of merged low-profile shield volcanoes erupted from central vents.