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Big Raven Formation
The Big Raven Formation is a stratigraphic unit of Quaternary age in northwestern British Columbia, Canada. It is the youngest and least voluminous geological formation of the Mount Edziza volcanic complex (MEVC); it overlies at least six older formations of this volcanic complex. The main volcanic rocks of the Big Raven Formation are alkali basalts and hawaiites, although a small volume of trachyte comprises the Sheep Track Member. These rocks were deposited by volcanic eruptions in the last 20,000 years during the Volcanism of the Mount Edziza volcanic complex#Fifth magmatic cycle, latest magmatic cycle of the MEVC. Alkali basalt and hawaiite are in the form of lava flows and small volcanic cones while trachyte of the Sheep Track Member is mainly in the form of volcanic ejecta which covers an area of about . The Big Raven Formation is widespread throughout the MEVC, occurring on or adjacent to the Arctic Lake Plateau, Arctic Lake, Big Raven Plateau, Big Raven and Kitsu Plateau, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Raspberry Formation
The Raspberry Formation is a stratigraphic unit of Miocene age in northwestern British Columbia, Canada. Naming The Raspberry Formation takes its name from Raspberry Pass, a mountain pass cutting through the central portion of the Mount Edziza volcanic complex. Geology The Raspberry Formation has a volume of , making it the third most voluminous geological formation comprising the Mount Edziza volcanic complex. It varies in elevation from less than along the Mess Creek Escarpment to near Armadillo Peak. The Raspberry Formation is overlain conformably by the Little Iskut Formation. An erosion surface separates the Raspberry Formation from the overlying Armadillo Formation and younger geological formations. Rocks of the Stikinia terrane underlie the Raspberry Formation. The Raspberry Formation consists of flat-lying alkali basalt and hawaiite flows. These flows are rusty brown and are interbedded with reddish-brown to yellow or orange scoria. The Raspberry Formation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanism Of The Mount Edziza Volcanic Complex
The Mount Edziza volcanic complex (MEVC) in British Columbia, Canada, has a long history of volcanism that spans more than 7 million years. It occurred during five cycles of magmatic activity, each producing less volcanic material than the previous one. Volcanism during these cycles has created several types of volcanoes, including cinder cones, stratovolcanoes, subglacial volcanoes, shield volcanoes and lava domes. The approximately volcanic plateau forming the base of the MEVC owes its origin to successive eruptions of highly mobile lava flows. Volcanic rocks such as basalt, trachybasalt, benmoreite, tristanite, mugearite, trachyte and rhyolite were deposited by multiple eruptions of the MEVC; the latter seven rock types are products of varying degrees of magmatic differentiation in underground magma reservoirs. At least 10 distinct flows of obsidian were produced by volcanism of the MEVC, some of which were exploited by Indigenous peoples of the Americas#North_America, indigeno ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
