DOCSLIB.ORG

Distribution, Nature, and Origin of Neogene–Quaternary Magmatism in the Northern Cordilleran Volcanic Province, Canada

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Distribution, Nature, and Origin of Neogene–Quaternary Magmatism in the Northern Cordilleran Volcanic Province, Canada Distribution, nature, and origin of Neogene–Quaternary magmatism in the northern Cordilleran volcanic province, Canada Benjamin R. Edwards* Igneous Petrology Laboratory, Department of Earth and Ocean Sciences, James K. Russell } University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada ABSTRACT Cordillera, driven by changes in relative these diverse volcanic rocks in space and time. plate motion between the Pacific and North We then use the compiled petrological and geo- The northern Cordilleran volcanic province American plates ca. 15–10 Ma. chemical data to address the origins of this alka- encompasses a broad area of Neogene to Qua- line magmatism and the structure of the litho- ternary volcanism in northwestern British Keywords: alkaline basalt, Canada, Cordil- sphere beneath the northern Cordilleran volcanic Columbia, the Yukon Territory, and adjacent leran, magmatism, Quaternary, volcanism. province. Specifically, we determine the source eastern Alaska. Volcanic rocks of the north- region characteristics of northern Cordilleran ern Cordilleran volcanic province range in INTRODUCTION volcanic province magmas using trace element age from 20 Ma to ca. 200 yr B.P. and are and isotopic data, and we produce a petrological dominantly alkali olivine basalt and hawai- Neogene to Quaternary magmatism in the image of the lithosphere using phase equilibria ite. A variety of more strongly alkaline rock Cordillera of North America is closely related to calculations for lavas and mantle peridotite types not commonly found in the North the current tectonic configuration between the xenoliths. Results of this analysis provide a basis American Cordillera are locally abundant in North American, Pacific, and Juan de Fuca plates on which to amplify the tectonic model we have the northern Cordilleran volcanic province. (Fig. 1). Where plate boundaries are convergent developed for the origins of northern Cordilleran These include nephelinite, basanite, and per- (e.g., Washington State), magmatism is domi- volcanic province magmatism (Edwards and alkaline phonolite, trachyte, and comendite. nated by calc-alkaline stratovolcanoes (e.g., Russell, 1999). The most MgO-rich nephelinites, basanites, CVA, Fig. 1). Where plate boundaries are domi- and alkaline basalts from throughout the nantly extensional and/or transtensional (e.g., GEOLOGIC SETTING northern Cordilleran volcanic province show southeastern California), mafic alkaline magma- trace element abundances and isotopic com- tism dominates (e.g., BR and RG, Fig. 1). The northern Cordilleran volcanic province positions that are consistent with an as- The most recently defined volcanic province comprises more than 100 mapped occurrences of thenospheric source region similar to that for in the North American Cordillera is the north- volcanic rocks within northwestern British Co- average oceanic island basalt and for post-5 ern Cordillera volcanic province (Edwards and lumbia, the Yukon, and easternmost Alaska (Fig. 1; Ma alkaline basalts from the Basin and Russell, 1999). The northern Cordilleran vol- north of lat 55°N and west of long 126°W). The Range. canic province comprises dominantly mafic, northern Cordilleran volcanic province designa- Our petrologic observations help con- Neogene, alkaline volcanic rocks distributed tion encompasses volcanic rocks that were previ- strain the origin of northern Cordilleran across the northern Canadian Cordillera (Fig. 1). ously referred to as the Stikine volcanic belt (e.g., volcanic province magmatism as well as Edwards and Russell (1999) proposed that Souther and Yorath, 1991). All volcanic centers lithosphere changes between the four major magmatism in the northern Cordilleran vol- are west of the Tintina fault system and east of basement terranes that underlie the province. canic province is linked to changes in far-field the Denali-Coast fault system (Fig. 2). Both of Results from phase equilibria calculations forces between the Pacific and North Ameri- these fault systems are major structural features and the spatial distributions of volcanic rock can plates. They showed that the timing and in the northern Cordillera that have accommo- types and magmatic inclusions are more volumetric rates of volcanism in the northern dated several hundred kilometers of mainly dex- consistent with the existence of thicker litho- Cordilleran volcanic province correlate with tral strike-slip motion since the Cretaceous (cf. sphere beneath Stikinia, which underlies the changes in the relative motions between the Gabrielse and Yorath, 1991). The Tintina-North- southern part of the northern Cordilleran Pacific and North American plates, from domi- ern Rocky Mountain Trench fault system sepa- volcanic province, than beneath the Cache nantly compressional to dominantly transten- rates autochthonous North American crust to the Creek and Yukon-Tanana terranes, which sional. east from allochthonous terranes to the west. The underlie the northern part of the northern Our objectives are twofold. Much of what has Denali fault system extends almost 2000 km Cordilleran volcanic province. Our results been published on volcanism in the northern from central Alaska to northwestern British Co- support a model for initiation of northern Cordilleran volcanic province derives from short lumbia, where it merges with the Coast Range Cordilleran volcanic province magmatism scientific or technical reports found in govern- fault system (cf. Wheeler and McFeeley, 1991). due to incipient rifting of the northern ment publications and unpublished theses. The Denali-Coast fault system is an approximate Therefore, our first aim is to compile these data boundary between more highly disrupted, al- *E-mail: [email protected]. and use the synthesis to map the distributions of lochthonous terranes to the west (e.g., Wrangellia) GSA Bulletin; August 2000; v. 112; no. 8; p. 1280–1295; 11 figures; 2 tables. 1280 NEOGENE-QUATERNARY MAGMATISM IN THE NORTHERN CORDILLERAN VOLCANIC PROVINCE AVA Prindle WVB DC NCVP Fort CP Selkirk AVB North NCVP America CRP CVA SRP Ak. Pacific Plate BR/RG WVB Alligator Lake Atlin Heart Y.T. Peaks N.W.T. T 120 Level B.C. 60 Edgecumbe Mtn. 56 Edziza Legend Hoodoo M 136 Volcanic complexes The S Thumb Volcanic centers Chilcotin basalt Aiyansh rnfr fault transform Queen Charlotte AVB 52 132 North Pacific American Plate Plate WGC Figure 2. Distribution of volcanic centers in the northern Cordilleran volcanic province (NCVP) with respect to major tectonostrati- graphic terrane boundaries and the Denali Explorer Plate and Tintina fault systems (after Wheeler and McFeely, 1991). Line of section shown is that used in Figures 8, 9, and 10. 200 km Juande Fuca Plate U.S.A. GVB and Yorath, 1991). The Cache Creek terrane, also Figure 1. Distribution of Neogene and Quaternary volcanic rocks in the Canadian Cordillera, allochthonous, is thought to have developed including: GVB—Garibaldi volcanic belt, WGC—Wells Gray-Clearwater volcanic field, AVB— largely in an oceanic basin; it consists of late Anaheim volcanic belt, WVB—Wrangell volcanic belt, and NCVP—the northern Cordilleran vol- Paleozoic to Mesozoic oceanic melange and canic province (modified from Hickson, 1991). M—Locations of Maitland, and T—Tuya volcanic abyssal peridotites intruded by younger granitic fields (Table 1) are also shown. The NCVP spans a region from DC—Dawson Creek, Yukon Ter- plutons (cf. Gabrielse and Yorath, 1991). The ritory, to S—Stewart, British Columbia. Inset shows the relationship of the NCVP to other vol- Yukon-Tanana and Cassiar terranes comprise dis- canic regimes in western North America and includes: AVA—Aleutian volcanic arc, CVA—the placed, autochthonous sedimentary and meta- Cascade volcanic arc, CP—Chilcotin plateau basalts; CRP—the Columbia River plateau basalt morphic rocks derived from North America field, SRP—the Snake River Plain, and BR/RG—the Basin and Range-Rio Grande rift system. (Mortensen, 1992; Gabrielse and Yorath, 1991). The southern margin of the northern Cordilleran volcanic province coincides with southwestern and larger, more coherent allochthonous ter- graphic terranes (Fig. 2), Stikinia, Cache Creek, Stikinia and is defined by isolated volcanic vents ranes to the east (e.g., Stikinia) (cf. Wheeler Yukon-Tanana, and Cassiar. Stikinia is an al- and eroded lava remnants south of the town of and McFeely, 1991). lochthonous suite of late Paleozoic and Mesozoic Stewart (Fig. 1). The southern limit of the northern Northern Cordilleran volcanic province mag- volcanic, plutonic, and sedimentary rocks thought Cordilleran volcanic province coincides with a gap matism is spread across four major tectonostrati- to have formed in an island-arc setting (Gabrielse in Neogene magmatism and the inferred northern Geological Society of America Bulletin, August 2000 1281 EDWARDS AND RUSSELL TABLE 1. SUMMARY OF LOCATIONS, AGES, VOLCANIC LANDFORMS, AND VOLUMES FOR NEOGENE TO QUATERNARY ALKALI BASALTIC CENTERS WITHIN THE NORTHERN CORDILLERAN VOLCANIC PROVINCE Volcanic field or center Location Age† Volcanic Volume§ Rock Source# Lat Long (Ma) landforms (km3) types (N) (W) Eastern Alaska (1) Prindle 63.72° 141.62° 3.57 ± 0.14, 6.26 ± 0.15 Cone, flow ~0.1 19, 54, 59, 78 or younger Western Yukon Territory (4) West Dawson Sixty Mile 64.05° 140.74° 17.2 ± 0.3 (*) Unknown <<0.001 Basanite 53 Clinton Creek 64.40° 140.63° 3.05 ± 0.22 Unknown <<0.001 52, 53 Forty Mile 64.38° 140.50° 19.9 ± 0.5 (*) Unknown <<0.001 53 Moose Creek 64.16° 140.91° Tertiary–Quaternary Unknown <<0.001 53 Central Yukon
Load more

Recommended publications
  • Geologic Storage Formation Classification: Understanding Its Importance and Impacts on CCS Opportunities in the United States
    BEST PRACTICES for: Geologic Storage Formation Classification: Understanding Its Importance and Impacts on CCS Opportunities in the United States First Edition Disclaimer This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference therein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed therein do not necessarily state or reflect those of the United States Government or any agency thereof. Cover Photos—Credits for images shown on the cover are noted with the corresponding figures within this document. Geologic Storage Formation Classification: Understanding Its Importance and Impacts on CCS Opportunities in the United States September 2010 National Energy Technology Laboratory www.netl.doe.gov DOE/NETL-2010/1420 Table of Contents Table of Contents 5 Table of Contents Executive Summary ____________________________________________________________________________ 10 1.0 Introduction and Background
    [Show full text]
  • Geologic Map of the Simcoe Mountains Volcanic Field, Main Central Segment, Yakama Nation, Washington by Wes Hildreth and Judy Fierstein
    Prepared in Cooperation with the Water Resources Program of the Yakama Nation Geologic Map of the Simcoe Mountains Volcanic Field, Main Central Segment, Yakama Nation, Washington By Wes Hildreth and Judy Fierstein Pamphlet to accompany Scientific Investigations Map 3315 Photograph showing Mount Adams andesitic stratovolcano and Signal Peak mafic shield volcano viewed westward from near Mill Creek Guard Station. Low-relief rocky meadows and modest forested ridges marked by scattered cinder cones and shields are common landforms in Simcoe Mountains volcanic field. Mount Adams (elevation: 12,276 ft; 3,742 m) is centered 50 km west and 2.8 km higher than foreground meadow (elevation: 2,950 ft.; 900 m); its eruptions began ~520 ka, its upper cone was built in late Pleistocene, and several eruptions have taken place in the Holocene. Signal Peak (elevation: 5,100 ft; 1,555 m), 20 km west of camera, is one of largest and highest eruptive centers in Simcoe Mountains volcanic field; short-lived shield, built around 3.7 Ma, is seven times older than Mount Adams. 2015 U.S. Department of the Interior U.S. Geological Survey Contents Introductory Overview for Non-Geologists ...............................................................................................1 Introduction.....................................................................................................................................................2 Physiography, Environment, Boundary Surveys, and Access ......................................................6 Previous Geologic
    [Show full text]
  • Holocene Tephras in Lake Cores from Northern British Columbia, Canada
    935 Holocene tephras in lake cores from northern British Columbia, Canada Thomas R. Lakeman, John J. Clague, Brian Menounos, Gerald D. Osborn, Britta J.L. Jensen, and Duane G. Froese Abstract: Sediment cores recovered from alpine and subalpine lakes up to 250 km apart in northern British Columbia con- tain five previously unrecognized tephras. Two black phonolitic tephras, each 5–10 mm thick, occur within 2–4 cm of each other in basal sediments from seven lakes in the Finlay River – Dease Lake area. The upper and lower Finlay tephras are slightly older than 10 220 – 10 560 cal year B.P. and likely originate from two closely spaced eruptions of one or two large volcanoes in the northern Cordilleran volcanic province. The Finlay tephras occur at the transition between deglacial sediments and organic-rich postglacial mud in the lake cores and, therefore, closely delimit the termination of the Fraser Glaciation in northern British Columbia. Sediments in Bob Quinn Lake, which lies on the east edge of the northern Coast Mountains, contain two black tephras that differ in age and composition from the Finlay tephras. The lower Bob Quinn tephra is 3–4 mm thick, basaltic in composition, and is derived from an eruption in the Iskut River volcanic field about 9400 cal years ago. The upper Bob Quinn tephra is 12 mm thick, trachytic in composition, and probably 7000–8000 cal years old. A fifth tephra occurs as a cryptotephra near the top of two cores from the Finlay River area and is correlated to the east lobe of the White River tephra (ca.
    [Show full text]
  • The Science Behind Volcanoes
    The Science Behind Volcanoes A volcano is an opening, or rupture, in a planet's surface or crust, which allows hot magma, volcanic ash and gases to escape from the magma chamber below the surface. Volcanoes are generally found where tectonic plates are diverging or converging. A mid-oceanic ridge, for example the Mid-Atlantic Ridge, has examples of volcanoes caused by divergent tectonic plates pulling apart; the Pacific Ring of Fire has examples of volcanoes caused by convergent tectonic plates coming together. By contrast, volcanoes are usually not created where two tectonic plates slide past one another. Volcanoes can also form where there is stretching and thinning of the Earth's crust in the interiors of plates, e.g., in the East African Rift, the Wells Gray-Clearwater volcanic field and the Rio Grande Rift in North America. This type of volcanism falls under the umbrella of "Plate hypothesis" volcanism. Volcanism away from plate boundaries has also been explained as mantle plumes. These so- called "hotspots", for example Hawaii, are postulated to arise from upwelling diapirs with magma from the core–mantle boundary, 3,000 km deep in the Earth. Erupting volcanoes can pose many hazards, not only in the immediate vicinity of the eruption. Volcanic ash can be a threat to aircraft, in particular those with jet engines where ash particles can be melted by the high operating temperature. Large eruptions can affect temperature as ash and droplets of sulfuric acid obscure the sun and cool the Earth's lower atmosphere or troposphere; however, they also absorb heat radiated up from the Earth, thereby warming the stratosphere.
    [Show full text]
  • Mountain Goat Population Ecology and Habitat Use Along the Juneau Access Road Corridor, Alaska
    Final Wildlife Research Report, ADFG/DWC/WRR-2012-02 Mountain goat population ecology and habitat use along the Juneau Access road corridor, Alaska Kevin S. White, David P. Gregovich, Grey W. Pendleton, Neil L. Barten, Ryan Scott, Anthony Crupi and Doug N. Larsen ©2005 ADFG/photo by Kevin White May 2012 Alaska Department of Fish and Game Division of Wildlife Conservation Final Wildlife Research Reports are fi nal reports detailing the objectives, methods, data collected and fi ndings of a particular research project undertaken by ADF&G Division of Wildlife Conservation staff and partners. They are written to provide broad access to information obtained through the project. While these are fi nal reports, further data analysis may result in future adjustments to the conclusions. Please contact the author(s) prior to citing material in these reports. These reports are professionally reviewed by research staff in the Division of Wildlife Conservation. They are provided a number for internal tracking purposes. This Wildlife Research Report was reviewed and approved for publication by Rod Flynn, Reseach Coodinator for Region 1, for the Division of Wildlife Conservation. Wildlife Research Reports are available from the Alaska Department of Fish and Game’s Division of Wildlife Conservation, PO Box 115526, Juneau, Alaska 99811-5526; phone (907) 465-4190; email: dfg.dwc.publications@ alaska.gov; website: www.adfg.alaska.gov. The report may also be accessed through most libraries, via interlibrary loan from the Alaska State Library or the Alaska Resources Library and Information Service (www.arlis.org). This document should be cited as: White, K. S., D.
    [Show full text]
  • Geology and Mineral Deposits Tulsequah Map-Area, British Columbia (104K)
    GEOLOGY AND MINERAL DEPOSITS TULSEQUAH MAP-AREA, BRITISH COLUMBIA (104K) 1.(50-1971-6J44 Technical Editor H. M. A. RJCl! Critical Readers J. O. WHUL~R HNll R. B. CAMPBELL Editor D. W>UT1! Text printed OD Georgian Olfset Smooth Finish Set iD Times Roman with 20th Century captioos by CANADIAN GOVEI\NMENT PJuN'TTNG BUReAU Artwork by C,\JlTOCRAPHlC UNIT, GSC 201339 FIGURE 1. View looking 'outhwe'l from the Tohllon Highland ocro" Tohomenie lake to the inner range' of the Coo,1 Mountain<. GEOLOGICAL SURVEY OF CANADA MEMOIR 362 GEOLOGY AND MINERAL DEPOSITS OF TULSEQUAH MAP-AREA, BRITISH COLUMBIA (104K) By J. G. Souther DEPARTMENT OF ENERGY, MINES AND RESOURCES CANADA © Crown Copyrighls reserved AvailabLe by mail from Information Canada, OIlOWO, rrom Geological SOf"ey or Canada. 601 Boolh St., Ollaw" nnd tll the following Jnformalion Canada b()Qk~hops: HALl FA>.' 1735 Barringlon Slreel MONTREAL 1182 SI. Cnlherine SlreeL West OrT,\WA 171 S Ialer Slreel TORONTO '22L Yonge Streel WINNlPEG 393 Ponage Avenue VA1'JCOUV£R 657 GranvilLe Street or through your bookseller A depos\t copy or Ihis publicalion is also 3yailable ror reference in public libraries acros~ Canada Price: $3.00 Calalogue No. M46·362 Price subju.1 to c.hange wilhaut nOlice Tnformiuion Canada Ollawa. 1971 PREFACE Taku River was used as a route to the Yukon during the Klondike gold rush of 1898 and this led to extensive prospecting, but it was not until 1937 that any of the silver-gold showings discovered in the intervening years were brought into production. Declining metal prices resulted in the closure of the last producing mine in 1957, but in recent years extensive geophysical and geochemical surveys have been made by several major exploration com­ panies and new prospects have been discovered.
    [Show full text]
  • Chapter 5: Canada
    156-164 U2 CH05 S1 TWIP-860976 3/22/04 10:49 PM Page 156 pter ha C 55 CanadaCanada Social Studies To learn more about Canada’s people Chapter Overview Visit The World and Its and places, view The World and Its People Web site at twip.glencoe.com and People Chapter 5 video. click on Chapter 5—Chapter Overviews to preview information about Canada. 156 156-164 U2 CH05 S1 TWIP-860976 3/22/04 10:49 PM Page 157 Compare-Contrast Make this foldable to help you analyze the similarities and differences between the landforms, climate, and cultures of northern and southern Canada. Step 1 Mark the midpoint of the side Step 2 Turn the paper and fold the edge of a sheet of paper. outside edges in to touch at the midpoint. Draw a mark at the midpoint. Step 3 Turn and label your foldable as shown. Northern Canada Southern Canada Reading and Writing As you read the chapter, collect and write information under the appropriate tab that will help you compare and contrast northern and southern Canada. Sharing a Border The boundary line between Canada and the United States forms the longest unprotected border in the world. Citizens of these countries have been allowed to travel freely across the border, which is symbolic of the free trade between these nations. ▼ ▼ Vancouver, British Columbia 156-164 U2 CH05 S1 TWIP-860976 3/22/04 10:50 PM Page 158 Guide to Reading Main Idea 11 A Resource-Rich Canada is a vast country with many landforms and resources.
    [Show full text]
  • Radiogenic Age and Isotopic Studies: Report 3
    GSCAN-P—89-2 CA9200982 GEOLOGICAL SURVEY OF CANADA PAPER 89-2 RADIOGENIC AGE AND ISOTOPIC STUDIES: REPORT 3 1990 Entity, Mtnat and Cnargi*, Mint* M n**ouroaa Canada ftoaioweat Canada CanadS '•if S ( >* >f->( f STAFF, GEOCHRONOLOGY SECTION: GEOLOGICAL SURVEY OF CANADA Research Scientists: Otto van Breemen J. Chris Roddick Randall R. Parrish James K. Mortensen Post-Doctoral Fellows: Francis 6. Dudas Hrnst Hegncr Visiting Scientist: Mary Lou Bevier Professional Scientists: W. Dale L<neridj:e Robert W. Sullivan Patricia A. Hunt Reginald J. Theriaul! Jack L. Macrae Technical Staff: Klaus Suntowski Jean-Claude Bisson Dianne Bellerive Fred B. Quigg Rejean J.G. Segun Sample crushing and preliminary mineral separation arc done by the Mineralogy Section GEOLOGICAL SURVEY OF CANADA PAPER 89-2 RADIOGENIC AGE AND ISOTOPIC STUDIES: REPORT 3 1990 ° Minister of Supply and Services Canada 1990 Available in Canada through authorized bookstore agents and other bookstores or by mail from Canadian Government Publishing Centre Supply and Services Canada Ottawa, Canada Kl A 0S9 and from Geological Survey of Canada offices: 601 Booth Street Ottawa, Canada Kl A 0E8 3303-33rd Street N.W., Calgary, Alberta T2L2A7 100 West Pender Street Vancouver, B.C. V6B 1R8 A deposit copy of this publication is also available for reference in public libraries across Canada Cat. No. M44-89/2E ISBN 0-660-13699-6 Price subject to change without notice Cover Description: Aerial photograph of the New Quebec Crater, a meteorite impact structure in northern Ungava Peninsula, Quebec, taken in 1985 by P.B. Robertson (GSC 204955 B-l). The diameter of the lake is about 3.4km and the view is towards the east-southeast.
    [Show full text]
  • P1616 Text-Only PDF File
    A Geologic Guide to Wrangell–Saint Elias National Park and Preserve, Alaska A Tectonic Collage of Northbound Terranes By Gary R. Winkler1 With contributions by Edward M. MacKevett, Jr.,2 George Plafker,3 Donald H. Richter,4 Danny S. Rosenkrans,5 and Henry R. Schmoll1 Introduction region—his explorations of Malaspina Glacier and Mt. St. Elias—characterized the vast mountains and glaciers whose realms he invaded with a sense of astonishment. His descrip­ Wrangell–Saint Elias National Park and Preserve (fig. tions are filled with superlatives. In the ensuing 100+ years, 6), the largest unit in the U.S. National Park System, earth scientists have learned much more about the geologic encompasses nearly 13.2 million acres of geological won­ evolution of the parklands, but the possibility of astonishment derments. Furthermore, its geologic makeup is shared with still is with us as we unravel the results of continuing tectonic contiguous Tetlin National Wildlife Refuge in Alaska, Kluane processes along the south-central Alaska continental margin. National Park and Game Sanctuary in the Yukon Territory, the Russell’s superlatives are justified: Wrangell–Saint Elias Alsek-Tatshenshini Provincial Park in British Columbia, the is, indeed, an awesome collage of geologic terranes. Most Cordova district of Chugach National Forest and the Yakutat wonderful has been the continuing discovery that the disparate district of Tongass National Forest, and Glacier Bay National terranes are, like us, invaders of a sort with unique trajectories Park and Preserve at the north end of Alaska’s panhan­ and timelines marking their northward journeys to arrive in dle—shared landscapes of awesome dimensions and classic today’s parklands.
    [Show full text]
  • Canadian Volcanoes, Based on Recent Seismic Activity; There Are Over 200 Geological Young Volcanic Centres
    Volcanoes of Canada 1 V4 C.J. Hickson and M. Ulmi, Jan. 3, 2006 • Global Volcanism and Plate tectonics Where do volcanoes occur? Driving forces • Volcano chemistry and eruption types • Volcanic Hazards Pyroclastic flows and surges Lava flows Ash fall (tephra) Lahars/Debris Flows Debris Avalanches Volcanic Gases • Anatomy of an Eruption – Mt. St. Helens • Volcanoes of Canada Stikine volcanic belt Presentation Outline Anahim volcanic belt Wells Gray – Clearwater volcanic field 2 Garibaldi volcanic belt • USA volcanoes – Cascade Magmatic Arc V4 Volcanoes in Our Backyard Global Volcanism and Plate tectonics In Canada, British Columbia and Yukon are the host to a vast wealth of volcanic 3 landforms. V4 How many active volcanoes are there on Earth? • Erupting now about 20 • Each year 50-70 • Each decade about 160 • Historical eruptions about 550 Global Volcanism and Plate tectonics • Holocene eruptions (last 10,000 years) about 1500 Although none of Canada’s volcanoes are erupting now, they have been active as recently as a couple of 4 hundred years ago. V4 The Earth’s Beginning Global Volcanism and Plate tectonics 5 V4 The Earth’s Beginning These global forces have created, mountain Global Volcanism and Plate tectonics ranges, continents and oceans. 6 V4 continental crust ic ocean crust mantle Where do volcanoes occur? Global Volcanism and Plate tectonics 7 V4 Driving Forces: Moving Plates Global Volcanism and Plate tectonics 8 V4 Driving Forces: Subduction Global Volcanism and Plate tectonics 9 V4 Driving Forces: Hot Spots Global Volcanism and Plate tectonics 10 V4 Driving Forces: Rifting Global Volcanism and Plate tectonics Ocean plates moving apart create new crust.
    [Show full text]
  • Pleistocene Volcanism in the Anahim Volcanic Belt, West-Central British Columbia
    University of Calgary PRISM: University of Calgary's Digital Repository Graduate Studies The Vault: Electronic Theses and Dissertations 2014-10-24 A Second North American Hot-spot: Pleistocene Volcanism in the Anahim Volcanic Belt, west-central British Columbia Kuehn, Christian Kuehn, C. (2014). A Second North American Hot-spot: Pleistocene Volcanism in the Anahim Volcanic Belt, west-central British Columbia (Unpublished doctoral thesis). University of Calgary, Calgary, AB. doi:10.11575/PRISM/25002 http://hdl.handle.net/11023/1936 doctoral thesis University of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission. Downloaded from PRISM: https://prism.ucalgary.ca UNIVERSITY OF CALGARY A Second North American Hot-spot: Pleistocene Volcanism in the Anahim Volcanic Belt, west-central British Columbia by Christian Kuehn A THESIS SUBMITTED TO THE FACULTY OF GRADUATE STUDIES IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY GRADUATE PROGRAM IN GEOLOGY AND GEOPHYSICS CALGARY, ALBERTA OCTOBER, 2014 © Christian Kuehn 2014 Abstract Alkaline and peralkaline magmatism occurred along the Anahim Volcanic Belt (AVB), a 330 km long linear feature in west-central British Columbia. The belt includes three felsic shield volcanoes, the Rainbow, Ilgachuz and Itcha ranges as its most notable features, as well as regionally extensive cone fields, lava flows, dyke swarms and a pluton. Volcanic activity took place periodically from the Late Miocene to the Holocene.
    [Show full text]
  • Pliocene and Pleistocene Volcanic Interaction with Cordilleran Ice Sheets, Damming of the Yukon River and Vertebrate Palaeontolo
    Quaternary International xxx (2011) 1e18 Contents lists available at SciVerse ScienceDirect Quaternary International journal homepage: www.elsevier.com/locate/quaint Pliocene and Pleistocene volcanic interaction with Cordilleran ice sheets, damming of the Yukon River and vertebrate Palaeontology, Fort Selkirk Volcanic Group, west-central Yukon, Canada L.E. Jackson Jr. a,*, F.E. Nelsonb,1, C.A. Huscroftc, M. Villeneuved, R.W. Barendregtb, J.E. Storere, B.C. Wardf a Geological Survey of Canada, Natural Resources Canada, 625 Robson Street, Vancouver, BC V6B5J3, Canada b Department of Geography, University of Lethbridge, 4401 University Drive, Lethbridge, Alberta T1K 3M4, Canada c Department of Geography, Thompson Rivers University, Box 3010, 900 McGill Road, Kamloops, BC V2C 5N3, Canada d Geological Survey of Canada, 601 Booth Street, Ottawa, Ontario, Canada e 6937 Porpoise Drive, Sechelt, BC V0N 3A4, Canada f Department of Earth Sciences, Simon Fraser University, 8888 University Drive, Burnaby, BC V2C 5N3, Canada article info abstract Article history: Neogene volcanism in the Fort Selkirk area began with eruptions in the Wolverine Creek basin ca. 4.3 Ma Available online xxx and persisted to ca. 3.0 Ma filling the ancestral Yukon River valley with at least 40 m of lava flows. Activity at the Ne Ch’e Ddhäwa eruptive center overlapped with the last stages of the Wolverine Creek eruptive centers. Hyaloclastic tuff was erupted between ca. 3.21 and 3.05 Ma. This eruption caused or was coincident with damming of Yukon River. The first demonstrable incursion of a Cordilleran ice sheet into the Fort Selkirk area was coincident with a second eruption of the Ne Ch’e Ddhäwa eruptive center ca.
    [Show full text]