The Mechanics of Subglacial Basaltic Lava Flow Emplacement: Inferring Paleo-Ice Conditions
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Physiography Geology
BRITISH COLUMBIA DEPARTMENT OF MINES HON. W. K. KIERNAN, Minister P. J. MULCAHY, Deputy Minister NOTES ON PHYSIOGRAPHY AND GEOLOGY OF (Bli BRITISH COLUMBIA b OFFICERS OF THE DEPARTMENT VICTCRIA, B.C. 1961 PHYSIOGRAPHY Physiographic divisions and names are established by the Geographic Board of Canada. Recently H. S. Bostock, of the Geological Survey of Canada, studied the physiography of the northern Cordilleran region; his report and maps are published CI I c Fig. 1. Rglief map of British Columbia. in Memoir 247 of the Geological Survey, Department of Mines and Resources, Ottawa. The divisions shown on the accompanying sketch, Figure 2, and the nomenclature used in the text are those proposed by Bostock. Most of the Province of British Columbia lies within the region of mountains and plateaus, the Cordillera of Western Canada, that forms the western border of the North American Continent. The extreme northeastern comer of the Province, lying east of the Cordillera, is part of the Great Plains region. The Rocky Mountain Area extends along the eastern boundary of the Province for a distance of 400 miles, and continues northwestward for an additional 500 miles entirely within the Province. The high, rugged Rocky Mountains, averaging about 50 miles in width, are flanked on the west by a remarkably long and straight valley, known as the Rocky Mountain Trench, and occupied from south to north by the Kootenay, Columbia, Canoe, Fraser, Parsnip, Finlay, Fox, and Kechika Rivers. Of these, the first four flow into the Pacific Ocean and the second four join the Mackenzie River to flow ultimately into the Arctic Ocean. -
Glacial Rebound and Plate Spreading: Results from the First Countrywide GPS Observations in Iceland
Geophys. J. Int. (2009) 177, 691–716 doi: 10.1111/j.1365-246X.2008.04059.x Glacial rebound and plate spreading: results from the first countrywide GPS observations in Iceland ∗ T. Arnad´ ottir,´ 1 B. Lund,2 W. Jiang,1 H. Geirsson,3 H. Bjornsson,¨ 4 P. Einarsson4 and T. Sigurdsson5 1Nordic Volcanological Center, Institute of Earth Sciences, University of Iceland, IS-101 Reykjav´ık, Iceland. E-mail: [email protected] 2Department of Earth Sciences, Uppsala University, Villavagen¨ 16, 752 36 Uppsala, Sweden 3Physics Department, Icelandic Meteorological Office, Reykjav´ık, Iceland 4Institute of Earth Sciences, University of Iceland, IS-101 Reykjav´ık, Iceland 5National Land Survey of Iceland, Akranes, Iceland Downloaded from https://academic.oup.com/gji/article/177/2/691/2023257 by guest on 30 September 2021 Accepted 2008 December 10. Received 2008 December 5; in original form 2008 June 12 SUMMARY Iceland is one of the few places on Earth where a divergent plate boundary can be observed on land. Direct observations of crustal deformation for the whole country are available for the first time from nationwide Global Positioning System (GPS) campaigns in 1993 and 2004. The plate spreading across the island is imaged by the horizontal velocity field and high uplift rates (≥10 mm yr−1) are observed over a large part of central and southeastern Iceland. Several earthquakes, volcanic intrusions and eruptions occurred during the time spanned by the measurements, causing local disturbances of the deformation field. After correcting for the largest earthquakes during the observation period, we calculate the strain rate field and find that the main feature of the field is the extension across the rift zones, subparallel to the direction of plate motion. -
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. -
British Columbia Geological Survey Geological Fieldwork 2003
TRACKING THE ESKAY RIFT THROUGH NORTHERN BRITISH COLUMBIA - GEOLOGY AND MINERAL OCCURRENCES OF THE UPPER ISKUT RIVER AREA (TELEGRAPH CREEK NTS 104G/1, 2, 7, 8, 9, 10) By D.J. Alldrick1, M.L. Stewart1, J.L. Nelson1 and K.A. Simpson2 KEYWORDS: Targeted Geoscience Initiative-II (TGI-II), The two-year study will cover 6,250 km2, extending Bedrock mapping, Eskay Creek, Eskay Rift, Hazelton 125 km north from the Eskay Creek mine to the Spectrum Group, Stuhini Group, Mineral deposits porphyry copper-gold deposit (Figure 2). The paved Stewart-Cassiar Highway (Highway 37) runs northward through the eastern part of the map area. In 2003, the first INTRODUCTION field season, an eight-person team mapped 70 km along the rift sequence between Kinaskan Lake and More The Eskay Creek gold-silver mine, located in Creek, west of the highway (Figure 2). northwest British Columbia, is an unusually high-grade The project area straddles the eastern edge of the ore deposit. The mining industry continues to spend more Coast Mountains and the broad valley of the upper Iskut than $2 million each year on exploration for similar River. This area lies within the Tahltan First Nation deposits in the area. The geologic setting at the minesite is traditional area and they participated directly in this well studied, but large tracts in north-central British project. Topography varys from rounded glacial valleys Columbia require more detailed surveys to determine if along the upper Iskut River, to the extensive Spatsizi favourable sites exist for formation and preservation of Plateau, to high serrated ridges and peaks that are being additional deposits. -
Tuyas: a Descriptive Genetic Classification
Dickinson College Dickinson Scholar Faculty and Staff Publications By Year Faculty and Staff Publications 3-2014 Tuyas: A Descriptive Genetic Classification J.K. Russell Benjamin R. Edwards Dickinson College Lucy Porritt C. Ryane Follow this and additional works at: https://scholar.dickinson.edu/faculty_publications Part of the Environmental Sciences Commons, Glaciology Commons, and the Volcanology Commons Recommended Citation Russell, J.K., B.R. Edwards, Lucy Porritt, and C. Ryane. "Tuyas: A Descriptive Genetic Classification." Quaternary Science Reviews 87 (2014): 70-81. https://www.sciencedirect.com/science/article/pii/ S027737911400002X This article is brought to you for free and open access by Dickinson Scholar. It has been accepted for inclusion by an authorized administrator. For more information, please contact [email protected]. Quaternary Science Reviews 87 (2014) 70e81 Contents lists available at ScienceDirect Quaternary Science Reviews journal homepage: www.elsevier.com/locate/quascirev Tuyas: a descriptive genetic classification J.K. Russell a,*, B.R. Edwards b, Lucy Porritt a,c, C. Ryane a a Volcanology & Petrology Laboratory, Department of Earth, Ocean & Atmospheric Sciences, University of British Columbia, Vancouver V6T 1Z4, Canada b Department of Earth Sciences, Dickinson College, Carlisle, PA 17013, USA c School of Earth Sciences, University of Bristol, Bristol, UK article info abstract Article history: We present a descriptive genetic classification scheme and accompanying nomenclature for glacio- Received 23 June 2013 volcanic edifices herein defined as tuyas: positive-relief volcanoes having a morphology resulting from ice Received in revised form confinement during eruption and comprising a set of lithofacies reflecting direct interaction between magma 23 December 2013 and ice/melt water. -
2014 Department Newsletter
Earth Sciences Newsletter 2014 The Dickin-stone-ian Department of Earth Sciences Participates in Baffin Island Field Trip by Marcus Key Thanks to the generosity of John (GEOL ‘78) and Susan Pohl (‘80), Professor Marcus Key, Liz Plascencia (ERSC ‘16), Melanie Campbell (ERSC ‘15), Leslie Milliman (ERSC ‘14) and Aleks Perpalaj (ERSC ‘14) were able to participate in an 11 day trip to Baffin Island to experience the geologic wonders of the Canadian high Arctic. In early August 2013, we set up two base camps by boat from Pond Inlet on Baffin Island at 73 degrees North latitude. The first was on Bylot Island where we did day hikes to Cretaceous sandstone outcrops (DSCN2094) and the Sirmilik glacier. The second was on Curry Island where we sea kayaked in a fjord carved into Precambrian metamorphics (DSCN2332) with narwhals. There were many firsts for us: first 24 hour daylight, first fresh polar bear tracks, first narwhals, first time sea kayaking in a fjord, and first time sea Kayaking around an iceberg. For additional photos of the trip visit our website. http://www.dickinson.edu/galleries/gallery/167/ baffin_island_field_trip Inside this issue: Department and Campus 1 News 2-7 A Letter from the Chair 4-5 Senior Research Projects 8-11 Faculty Publications 12-16 Faculty Updates 17-21 Alumni Updates 22-34 Contact Information 35 Greenland Expedition 2014 By Ben Edwards Thanks to the ongoing generosity of John (GEOL ’78) and Susan Pohl (’80), the Earth Sciences department sent another five member team (Ben Edwards, Ariana Auerbach ‘16, Katie Mattern ‘16, Amanda Santilla ‘17, Will Kochtitzky ‘16) to explore geology and climate change, this time near the second largest ice sheet on earth in Greenland. -
The Hyaloclastite Ridge Formed in the Subglacial 1996 Eruption in Gjfilp, Vatnaj6kull, Iceland: Present Day Shape and Future Preservation
The hyaloclastite ridge formed in the subglacial 1996 eruption in Gjfilp, Vatnaj6kull, Iceland: present day shape and future preservation M. T. GUDMUNDSSON, F. PALSSON, H. BJORNSSON & ~. HOGNADOTTIR Science Institute, University of Iceland, Hofsvallag6tu 53, 107 Reykjavik, Iceland (e-mail: [email protected]) Abstract: In the Gjfilp eruption in 1996, a subglacial hyaloclastite ridge was formed over a volcanic fissure beneath the Vatnaj6kull ice cap in Iceland. The initial ice thickness along the 6 km-long fissure varied from 550 m to 750 m greatest in the northern part but least in the central part where a subaerial crater was active during the eruption. The shape of the subglacial ridge has been mapped, using direct observations of the top of the edifice in 1997, radio echo soundings and gravity surveying. The subglacial edifice is remarkably varied in shape and height. The southern part is low and narrow whereas the central part is the highest, rising 450 m above the pre-eruption bedrock. In the northern part the ridge is only 150-200m high but up to 2kin wide, suggesting that lateral spreading of the erupted material occurred during the latter stages of the eruption. The total volume of erupted material in Gj~tlp was about 0.8 km 3, mainly volcanic glass. The edifice has a volume of about 0.7 km 3 and a volume of 0.07 km 3 was transported with the meltwater from Gj~lp and accumulated in the Grimsv6tn caldera, where the subglacial lake acted as a trap for the sediments. This meltwater-transported material was removed from the southern part of the edifice during the eruption. -
Newsletters and Other Draft Nations, the Public and Provincial Organizations and Material
SSttiikkiinnee CCoouunnttrryy PPrrootteecctteedd AArreeaass NNeewwsslleetttteerr NNuummbbeerr11 Volume 1 February 2000 Management Planning is commencing for Stikine Country Protected Areas You are urged to become involved and provide your advice. Skeena District Parks Involved Spatsizi Plateau Wilderness Park Mt. Edziza Provincial Park Tatlatui Provincial Park Stikine River Recreation Area Mt. Edziza Recreation Area Kinaskan Lake Provincial Park Gladys Lake Ecological Reserve “The Stikine River Recreation Area near Highway 37.” Background Stikine Country contains some of the most outstanding protected areas in British Columbia. They lie within the traditional territory of the Tahltan First Nations. Each of these protected areas is important in its own right, and together they protect provincial and international values for future generations. These include: Ä largely intact predator/prey ecosystems Ä provincially important populations of caribou, mountain sheep, mountain goats, grizzly bears and wolf Ä spectacular mountain, plateau, river and volcanic landscapes Ä important archaeological sites, cultural and heritage values and activities of the Tahltan First Nations Ä internationally significant wilderness recreation and tourism activities such as nature appreciation, rafting, canoeing, hiking, hunting, angling and horseback riding Planning is proposed to begin shortly and to be completed by the fall of 2001. A systems approach to planning is being undertaken in recognition of the ecosystem connectivity and related issues among this -
The Tuya-Teslin Areal Northern British Columbia
BRITISH COLUMBIA DEPARTMENT OF MINES HON. E. C. CARSON, Minister JOHN F. WALKER, Dopulu Minis/#, BULLETIN No. 19 THE TUYA-TESLIN AREAL NORTHERN BRITISH COLUMBIA by K. DeP. WATSON and W. H.MATHEWS 1944 CONTENTS. P*GS SUMMARY.................................................................................................................................... 5 CHAPTER I.-Introduction ....................................................................................................... 6 Location............................................................................................................................. 6 Access................................................................................................................................. 7 Field-work .......................................................................................................................... 7 Acknowledgments ............................................................................................................. 7 Previous Work.................................................................................................................. 8 CHAPTER11.- I Topography ........................................................................................................................ 9 Kawdy Plateau.......................................................................................................... 9 Trenches ...................................................................................................................... 9 Teslin -
Ice Core Drilling and Subglacial Lake Studies on the Temperate Ice Caps in Iceland
Ice core drilling and subglacial lake studies on the temperate ice caps in Iceland Iceland astride the Mid-Atlantic ridge Lecture # 36 Astrobiology Winter School Ice drilling projects in Iceland University of Hawaii, Jan. 2005 Thorsteinn Thorsteinsson ([email protected]) National Energy Authority Ice cover during the late glacial period. Combination of hot spot volcanism, spreading on the Mid-Atlantic ridge and glaciation leads to unusual geology. From Thordarson and Höskuldsson (2003). Subglacial volcanism beneath an ice sheet creates unusual landforms: Tuyas (tablemountains) and ridges. Herðubreið, N-Iceland Submarine eruptions create similar formations. Biologicial colonization monitored from the beginning Surtsey eruption, S. of Iceland, 1963-1967. Recent subglacial eruption in Grímsvötn, Vatnajökull ice cap. Jökulsárgljúfur canyons, N. Iceland: Formed in a catastrophic flood from Vatnajökull 2500 years ago. Icelandic analogs to hillside gullies on Mars Mars Mars Iceland Iceland Iceland Temperate ice caps Hofsjökull, 890 km2 cover >10% of Iceland Vatnajökull 2 Langjökull 8000 km 2 920 km Max. thickness: 950 m Mýrdalsjökull 550 km2 - Dynamic ice caps in a maritime climate. - High accumulation rates (2-4 m w.eq. yr-1) - Extensive melting during summer, except at highest elevations (> 1800 m) - Mass balance of ice caps negative since 1995 1972: A 415 m ice core was drilled on the NW-part of Vatnajökull Activities not continued at that time, drill was discarded. Mass balance of Hofsjökull Ice Cap 4 2 0 Winter balance -2 Summer balance H2O Net balance m -4 Cumulative mass balance -6 -8 -10 1987 1992 1997 2002 Climate, Water, Energy: A research project investigating the effect of climate change on energy production in the Nordic countries Temperature increase 1990-2050 °C CWE uses IPCC data to create scenarios for temperature and precipitation change in the Nordic region in the future Modelled change in volume of Hofsjökull ice cap 2000-2002, Modelled glacial meltwater using four different dT and dP discharge (run-off) 2000-2200. -
Large Igneous Provinces and Mass Extinctions: an Update
Downloaded from specialpapers.gsapubs.org on April 29, 2015 OLD G The Geological Society of America Special Paper 505 2014 OPEN ACCESS Large igneous provinces and mass extinctions: An update David P.G. Bond* Department of Geography, Environment and Earth Science, University of Hull, Hull HU6 7RX, UK, and Norwegian Polar Institute, Fram Centre, 9296 Tromsø, Norway Paul B. Wignall School of Earth and Environment, University of Leeds, Leeds LS2 9JT, UK ABSTRACT The temporal link between mass extinctions and large igneous provinces is well known. Here, we examine this link by focusing on the potential climatic effects of large igneous province eruptions during several extinction crises that show the best correlation with mass volcanism: the Frasnian-Famennian (Late Devonian), Capi- tanian (Middle Permian), end-Permian, end-Triassic, and Toarcian (Early Jurassic) extinctions. It is clear that there is no direct correlation between total volume of lava and extinction magnitude because there is always suffi cient recovery time between individual eruptions to negate any cumulative effect of successive fl ood basalt erup- tions. Instead, the environmental and climatic damage must be attributed to single- pulse gas effusions. It is notable that the best-constrained examples of death-by- volcanism record the main extinction pulse at the onset of (often explosive) volcanism (e.g., the Capitanian, end-Permian, and end-Triassic examples), suggesting that the rapid injection of vast quantities of volcanic gas (CO2 and SO2) is the trigger for a truly major biotic catastrophe. Warming and marine anoxia feature in many extinc- tion scenarios, indicating that the ability of a large igneous province to induce these proximal killers (from CO2 emissions and thermogenic greenhouse gases) is the single most important factor governing its lethality. -
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.