This Jurassic ammonite is from an all but inaccessible site in Sayward, Bonanza Group, Vancouver Island. By the time these ammonites were being buried in sediment, Wrangellia, the predominately volcanic terrane that now forms Vancouver Island and the Queen Charlotte Islands, had made its way to the northern mid-latitudes. Within the basal part of the sequence, sedimentary beds are found interbedded with lapilli and crystal-tuffs. They include maroon tuffaceous sandstone, orange-grey sandstone, granule sandstone and conglomerate. Ammonites are found alongside gastropods and pelecypods. The Bonanza group is estimated to be at least 1000 metres thick. This detail of the Jurassic ammonite, Paltechioceras sp. shot with an ultra-low f-stop, is from an all but inaccessible site in Sayward, Bonanza Group, Vancouver Island.
Coroniceras of Wrangellia
Comments