Radiolarian investigations linked to geological mapping in the Canadian Cordillera has led to generate an important database with extended geographic and chronologic ranges (Table). Within the Cordillera, radiolarians are known so far from the Ordovician to the Cretaceous (radiolarians lived from Cambrian to the present). In Mesozoic time, marine terranes accreted to the North American margin contain large quantities of radiolarian-bearing rocks, such as the Cache Creek terrane which crops out over 1500 km along the Cordillera from Southern British Columbia to the Yukon (see map). These results (Cordey, 1998) show the age-younging of accreted oceanic basin towards the W in relation to the progressive amalgamation of terranes along the North-American margin during the Phanerozoic, supporting the process of continental accretion.
Location map from: "Long-lived Panthalassic remnant: the Bridge
River accretionary complex, Canadian Cordillera, by F. Cordey and P. Schiarizza,
Geology, 1993, v. 21, p. 263-266". Radiolarian localities range in age from
Early Carboniferous to Middle Jurassic.