The Nahlin Fault is a northeast-dipping thrust fault in the Northern Interior of British Columbia, Canada. [1] It forms a western boundary of the Cache Creek terrane. [2]
The North Cascades are a section of the Cascade Range of western North America. They span the border between the Canadian province of British Columbia and the U.S. state of Washington and are officially named in the U.S. and Canada as the Cascade Mountains. The portion in Canada is known to Americans as the Canadian Cascades, a designation that also includes the mountains above the east bank of the Fraser Canyon as far north as the town of Lytton, at the confluence of the Thompson and Fraser Rivers.
The Saint Elias Mountains are a subgroup of the Pacific Coast Ranges, located in southeastern Alaska in the United States, Southwestern Yukon and the very far northwestern part of British Columbia in Canada. The range spans Wrangell-St. Elias National Park and Preserve in the United States and Kluane National Park and Reserve in Canada and includes all of Glacier Bay National Park in Alaska. In Alaska, the range includes parts of the city/borough of Yakutat and the Hoonah-Angoon and Valdez-Cordova census areas.
Nootka Island is the largest island off the west coast of Vancouver Island in British Columbia, Canada. It is 510 square kilometres (200 sq mi) in area. It is separated from Vancouver Island by Nootka Sound and its side-inlets, and is located within Electoral Area A of the Strathcona Regional District.
The Lewis Range is a mountain range located in the Rocky Mountains of northern Montana, United States and extreme southern Alberta, Canada. It was formed as a result of the Lewis Overthrust, a geologic thrust fault involving the overlying of younger Cretaceous rocks by older Proterozoic rocks. The range is located within Waterton Lakes National Park in Alberta, Canada and Glacier National Park and the Bob Marshall Wilderness Complex in Montana, United States. The highest peak is Mount Cleveland at 10,479 ft (3,194 m).
The Fairweather Range is the unofficial name for a mountain range located in the U.S. state of Alaska and the Canadian province of British Columbia. It is the southernmost range of the Saint Elias Mountains. The northernmost section of the range is situated in Tatshenshini-Alsek Provincial Park while the southernmost section resides in Glacier Bay National Park, in the Hoonah-Angoon Census Area. In between it goes through the southeastern corner of Yakutat Borough. Peaks of this range include Mount Fairweather and Mount Quincy Adams 4,150 m (13,615 ft).
The Northern Cordilleran Volcanic Province (NCVP), formerly known as the Stikine Volcanic Belt, is a geologic province defined by the occurrence of Miocene to Holocene volcanoes in the Pacific Northwest of North America. This belt of volcanoes extends roughly north-northwest from northwestern British Columbia and the Alaska Panhandle through Yukon to the Southeast Fairbanks Census Area of far eastern Alaska, in a corridor hundreds of kilometres wide. It is the most recently defined volcanic province in the Western Cordillera. It has formed due to extensional cracking of the North American continent—similar to other on-land extensional volcanic zones, including the Basin and Range Province and the East African Rift. Although taking its name from the Western Cordillera, this term is a geologic grouping rather than a geographic one. The southmost part of the NCVP has more, and larger, volcanoes than does the rest of the NCVP; further north it is less clearly delineated, describing a large arch that sways westward through central Yukon.
The Explorer Ridge is a mid-ocean ridge, a divergent tectonic plate boundary located about 241 km (150 mi) west of Vancouver Island, British Columbia, Canada. It lies at the northern extremity of the Pacific spreading axis. To its east is the Explorer plate, which together with the Juan de Fuca plate and the Gorda plate to its south, is what remains of the once-vast Farallon plate which has been largely subducted under the North American plate. The Explorer Ridge consists of one major segment, the Southern Explorer Ridge, and several smaller segments. It runs northward from the Sovanco fracture zone to the Queen Charlotte triple junction, a point where it meets the Queen Charlotte Fault and the northern Cascadia subduction zone.
The geology of the Pacific Northwest includes the composition, structure, physical properties and the processes that shape the Pacific Northwest region of North America. The region is part of the Ring of Fire: the subduction of the Pacific and Farallon Plates under the North American Plate is responsible for many of the area's scenic features as well as some of its hazards, such as volcanoes, earthquakes, and landslides.
A horse, in geology, is any block of rock completely separated from the surrounding rock either by mineral veins or fault planes. In mining, a horse is a block of country rock entirely encased within a mineral lode. In structural geology the term was first used to describe the thrust-bounded imbricates found within a thrust duplex. In later literature it has become a general term for any block entirely bounded by faults, whether the overall deformation type is contractional, extensional or strike-slip in nature.
The 1949 Queen Charlotte Islands earthquake struck Haida Gwaii and the Pacific Northwest coast at 8:01 p.m. PDT on August 21. The earthquake had a moment magnitude of 8.0 and a surface-wave magnitude of 8.1. The maximum Mercalli Intensity in the event was VIII (Severe).
The Olympic–Wallowa lineament (OWL) is a series of geologic structures oriented from northwest to southeast for 650 km (400 mi) across Washington and northeast Oregon in the United States, passing through the Seattle area and including notable features east of the Cascade Range such as the Yakima Fold Belt and Wallowa Mountains. It was first reported by cartographer Erwin Raisz in 1945 on a relief map of the continental United States. Some geologists have questioned the existence of a geological relationship between the individual structures along the lineament suggesting it is an optical illusion. The origin of this feature in its entirety is not well understood with multiple hypotheses on the subject. The Olympic–Wallowa lineament likely predates the Columbia River Basalt Group.
Grenville Channel is a strait on the North Coast of British Columbia, Canada, between Pitt Island and the mainland to the south of Prince Rupert. It is part of the Inside Passage shipping route, about 45 nautical miles long and is 0.2 nautical miles wide at its narrowest point.
The Straight Creek Fault (SCF) is the principal north-south strike-slip fault in the state of Washington, with a minimum of 90 kilometers of right-lateral offset, and a major geological structure in the North Cascade mountains, where it separates the pre-Cenozoic igneous and metamorphic rocks of the North Cascades on the east from the younger accreted terranes on the west. The SCF can be traced from its junction with the Olympic–Wallowa Lineament (OWL) near the town of Easton northward into British Columbia, where it joins the Fraser River Fault system; the combined system is known as the Fraser—Straight Creek Fault system (FSCF).
The Brothers Fault Zone (BFZ) is the most notable of a set of northwest-trending fault zones including the Eugene–Denio, McLoughlin, and Vale zones that dominate the geological structure of most of Oregon. These are also representative of a regional pattern of generally northwest-striking geological features ranging from Walker Lane on the California–Nevada border to the Olympic–Wallowa Lineament in Washington; these are generally associated with the regional extension and faulting of the Basin and Range Province, of which the BFZ is considered the northern boundary.
The Devastator Assemblage is a geological formation comprising a portion of the Mount Meager massif in southwestern British Columbia, Canada. It is named after Devastator Peak, the lowest and southernmost subsidiary peak of Meager. The south and west flanks of Pylon Peak and Devastator Peak are made of The Devastator Assemblage rocks.
The Leech River Fault extends across the southern tip of Vancouver Island in British Columbia, Canada, creating the distinctively straight, narrow, and steep-sided valley, occupied by Loss Creek and two reservoirs, that runs from Sombrio Point due east to the Leech River, and then turns southeast to run past Victoria. It is a thrust fault that marks the northernmost exposure of the Crescent Terrane, where basalt of the Metchosin Igneous Complex is dragged under Vancouver Island by the subducting Juan de Fuca plate. About ten kilometres north the nearly parallel San Juan Fault marks the southern limit of rock of the Wrangellia terrane, which underlies most of Vancouver Island. Between these two northeast-dipping thrust faults are the Leech River Complex and the Pandora Peak Unit. These, along with the Pacific Rim Complex further up the coast, are remnants of the Pacific Rim Terrane which was crushed between Wrangellia and Siletzia. The contact between the bottom of Wrangellia and the top of the subducted PRT continues northwest along the coast as the West Coast Fault, and southeast towards Victoria as the Survey Mountain Fault. The Leech River Fault (LRF) extends off-shore towards Cape Flattery, where the Crescent—Pacific Rim contact continues northwest as the Tofino Fault (TF).
The Aire Valley Fault is an inactive strike slip fault in Yorkshire, England. It is considered a northwestern continuation of the Morley-Campsall Fault Belt and extends northwards from the Huddersfield and Wakefield area into the South Craven fault. It is connected to the Denholme Clough Fault.
The Yakima Fold Belt of south-central Washington, also called the Yakima fold-and-thrust belt, is an area of topographical folds raised by tectonic compression. It is a 14,000 km2 (5,400 sq mi) structural-tectonic sub province of the western Columbia Plateau Province resulting from complex and poorly understood regional tectonics. The folds are associated with geological faults whose seismic risk is of particular concern to the nuclear facilities at the Hanford Nuclear Reservation and major dams on the Columbia and Snake Rivers.
The Frenchman Hills are hills in Grant County, Washington, United States of America. The high point is 1,640 feet (500 m). They are an anticlinal fold in the northeastern part of the larger Yakima Fold Belt. They likely take their name for one of the first non-native residents in the area, who lived near Low Gap in the 1860s and 1870s and was known only as The Frenchman.