Wopmay orogen

Wopmay orogeny is the geological term for a mountain building on the western edge of the Canadian Shield. The mountains now worn comes from the Paleoproterozoic (ca. 2000 to 1800 mya ) on the super-continent Kenorland. The Acasta gneisses from the Hadean from 4030 mya - - one of the world's oldest rocks was a result of this unfolding revealed transported.

The rock consequences of Wopmay orogeny show - unique in the world - in the north-western Canada, on the western edge of the craton the even older azoic / archaic Slave Province, where they form the Earth's crust and the lithosphere. Accordingly, this area provides a spatial and temporal link between the archaic parts of the Northwest Territories at Yellowknife with his diamonds, radium, silver and gold deposits and the Phanerozoic Cordillera and shows the development of the north-western North America since the early history of the Earth.

During the two main stages of the collision of the primeval continental plates tectonic areas of Hottah Lake 2000 mya, today's Nahanni National Park with the Mackenzie Mountains 1840 mya, the volcanic arc to the Great Bear Lake and Fort Simpson Valley emerged.

The study of subduction by the Canadian Lithoprobe project - SNORCLE (Slave Northern Cordillera lithospheric evolution) occurs at depths up to 100 km by seismic reflection / refraction and electromagnetic profiles. The Fort Simpson basin is deep up to 25 km, but is largely buried beneath the thin western sedimentary basin of Canada. Some of the shallow Proterozoic strata of the Wopmay - orogen extend to the Cordilleras and British Columbia.

Links, sources

• Homepage Lithoprobe Canada
• The SNORCLE project
• Frederick A. Cook: Probing the lithosphere of the Wopmay Orogen. Presentation of the research project Lithoprobe SNORCLE (Slave Northern Cordillera lithospheric evolution) (PDF file, 64 kB)

• Orogeny