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Volcanic Reconstruction of the Archean North Rhyolite, Kidd Creek Mine, Timmins, Ontario, Canada
January 2004 Issue 80 Volcanic Reconstruction of the Archean North Rhyolite, Kidd Creek Mine, Timmins, Ontario, Canada Michelle DeWolfe Harold L. Gibson Mineral Exploration Research Centre Laurentian University Ramsey Lake Road, Sudbury, Ontario, P3E 6B5, Email: [email protected] David Richardson Falconbridge Limited Kidd Mining Division, PO Box 2002, Hwy 655, Timmins, Ontario, P4N 7K1 John Ayer Ontario Geological Survey Willet Green Miller Centre, Ramsey Lake Road, Sudbury, Ontario, P3E 6B5 Fig. 1. General geology map showing the Abitibi greenstone belt and Introduction the location of the Kidd Creek mine approximately 24 km north of A succession of volcanic rocks collectively known as the Timmins (modified from Bleeker and Hester, 1999). North Rhyolite (NR) is located directly northeast of the giant Kidd Creek Cu-Zn-Ag volcanogenic massive sulfide (VMS) thermal alteration away from the deposit. Understanding the deposit, within the Abitibi greenstone belt of the Superior prov- large-scale volcanic environment, which hosts the NR and the ince (Figs. 1 and 2). The NR has been interpreted as a lateral Kidd Creek orebodies, will allow a better comparison between extension of the Kidd Creek mine stratigraphy (Hannington et the environment in which the Kidd Creek deposit formed and the al., 1999a). However, detailed work on the stratigraphy and environment of formation for other VMS deposits. This may structure of the NR, and its relationship to the mine stratigraphy, also help to create a better understanding of the environments -
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 -
Origin and Character of Loesslike Silt in the Southern Qinghai-Xizang (Tibet) Plateau, China
Origin and Character of Loesslike Silt in the Southern Qinghai-Xizang (Tibet) Plateau, China U.S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 1549 Cover. View south-southeast across Lhasa He (Lhasa River) flood plain from roof of Potala Pal ace, Lhasa, Xizang Autonomous Region, China. The Potala (see frontispiece), characteristic sym bol of Tibet, nses 308 m above the valley floor on a bedrock hill and provides an excellent view of Mt. Guokalariju, 5,603 m elevation, and adjacent mountains 15 km to the southeast These mountains of flysch-like Triassic clastic and volcanic rocks and some Mesozoic granite character ize the southernmost part of Northern Xizang Structural Region (Gangdese-Nyainqentanglha Tec tonic Zone), which lies just north of the Yarlung Zangbo east-west tectonic suture 50 km to the south (see figs. 2, 3). Mountains are part of the Gangdese Island Arc at south margin of Lhasa continental block. Light-tan areas on flanks of mountains adjacent to almost vegetation-free flood plain are modern and ancient climbing sand dunes that exhibit evidence of strong winds. From flood plain of Lhasa He, and from flood plain of much larger Yarlung Zangbo to the south (see figs. 2, 3, 13), large dust storms and sand storms originate today and are common in capitol city of Lhasa. Blowing silt from larger braided flood plains in Pleistocene time was source of much loesslike silt described in this report. Photograph PK 23,763 by Troy L. P6w6, June 4, 1980. ORIGIN AND CHARACTER OF LOESSLIKE SILT IN THE SOUTHERN QINGHAI-XIZANG (TIBET) PLATEAU, CHINA Frontispiece. -
The Mineralogy and Chemistry of the Anorogenic Tertiary Silicic Volcanics
JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 86, NO. Bll, PAGES 10242-10256, NOVEMBER 10, 1981 The Mineralogyand Chemistryof the AnorogenicTertiary SilicicVolcanics of S.E. Queenslandand N.E. New South Wales, Australia A. EWART Departmentof Geology& Mineralogy,University of Queensland,St. Lucia,Brisbane, Queensland 4067 The Late Oligocene-EarlyMiocene volcanismof this regionis chemicallystrongly bimodal; the mafic lavas(volmetrically dominant) comprise basalts, hawaiites, and tholeiiticandesites, while the silicic eruptivesare mainly comendites,potassic trachytes, and potassic,high-silica rhyolites.The comendites and rhyoliteshave distinctivetrace element abundancepatterns, notably the extreme depletionsof Sr, Ba, Mg, Mn, P, Cr, V, and Eu, and the variable em'ichraentof suchelements as Rb, Zr, Pb, Nb, Zn, U, and Th. The trachytesexhibit thesecharacteristics to lesserdegrees. The comenditesare distinguished from the rhyolitesby their overall relative enrichmentof the more highly chargedcations (e.g., LREE, Nb, Y, and especiallyZr) and Zn. The phenocrystmineralogy of the trachytesand rhyolitescomprises various combinationsof the following phases:sodic plagioclase(albite-andesine), calcic anorthoclase, sanidine, quartz, ferroaugite-ferrohedenbergite,ferrohypersthene, fayalitic olivine, ilmenite, titano- magnetite,and rarely biotite (near annite) and Fe-hastingsiticamphibole. Accessories include apatite, zircon, chevkinite (ferrohedenbergite-bearingrhyolites only), and allanite (amphibole and botite rhyo- lites only). The comenditesgenerally contain -
(2000), Voluminous Lava-Like Precursor to a Major Ash-Flow
Journal of Volcanology and Geothermal Research 98 (2000) 153–171 www.elsevier.nl/locate/jvolgeores Voluminous lava-like precursor to a major ash-flow tuff: low-column pyroclastic eruption of the Pagosa Peak Dacite, San Juan volcanic field, Colorado O. Bachmanna,*, M.A. Dungana, P.W. Lipmanb aSection des Sciences de la Terre de l’Universite´ de Gene`ve, 13, Rue des Maraıˆchers, 1211 Geneva 4, Switzerland bUS Geological Survey, 345 Middlefield Rd, Menlo Park, CA, USA Received 26 May 1999; received in revised form 8 November 1999; accepted 8 November 1999 Abstract The Pagosa Peak Dacite is an unusual pyroclastic deposit that immediately predated eruption of the enormous Fish Canyon Tuff (ϳ5000 km3) from the La Garita caldera at 28 Ma. The Pagosa Peak Dacite is thick (to 1 km), voluminous (Ͼ200 km3), and has a high aspect ratio (1:50) similar to those of silicic lava flows. It contains a high proportion (40–60%) of juvenile clasts (to 3–4 m) emplaced as viscous magma that was less vesiculated than typical pumice. Accidental lithic fragments are absent above the basal 5–10% of the unit. Thick densely welded proximal deposits flowed rheomorphically due to gravitational spreading, despite the very high viscosity of the crystal-rich magma, resulting in a macroscopic appearance similar to flow- layered silicic lava. Although it is a separate depositional unit, the Pagosa Peak Dacite is indistinguishable from the overlying Fish Canyon Tuff in bulk-rock chemistry, phenocryst compositions, and 40Ar/39Ar age. The unusual characteristics of this deposit are interpreted as consequences of eruption by low-column pyroclastic fountaining and lateral transport as dense, poorly inflated pyroclastic flows. -
Source to Surface Model of Monogenetic Volcanism: a Critical Review
Downloaded from http://sp.lyellcollection.org/ by guest on September 28, 2021 Source to surface model of monogenetic volcanism: a critical review I. E. M. SMITH1 &K.NE´ METH2* 1School of Environment, University of Auckland, Auckland, New Zealand 2Volcanic Risk Solutions, Massey University, Palmerston North 4442, New Zealand *Correspondence: [email protected] Abstract: Small-scale volcanic systems are the most widespread type of volcanism on Earth and occur in all of the main tectonic settings. Most commonly, these systems erupt basaltic magmas within a wide compositional range from strongly silica undersaturated to saturated and oversatu- rated; less commonly, the spectrum includes more siliceous compositions. Small-scale volcanic systems are commonly monogenetic in the sense that they are represented at the Earth’s surface by fields of small volcanoes, each the product of a temporally restricted eruption of a composition- ally distinct batch of magma, and this is in contrast to polygenetic systems characterized by rela- tively large edifices built by multiple eruptions over longer periods of time involving magmas with diverse origins. Eruption styles of small-scale volcanoes range from pyroclastic to effusive, and are strongly controlled by the relative influence of the characteristics of the magmatic system and the surface environment. Gold Open Access: This article is published under the terms of the CC-BY 3.0 license. Small-scale basaltic magmatic systems characteris- hazards associated with eruptions, and this is tically occur at the Earth’s surface as fields of small particularly true where volcanic fields are in close monogenetic volcanoes. These volcanoes are the proximity to population centres. -
Geochemistry of Sideromelane and Felsic Glass Shards in Pleistocene Ash Layers at Sites 953, 954, and 9561
Weaver, P.P.E., Schmincke, H.-U., Firth, J.V., and Duffield, W. (Eds.), 1998 Proceedings of the Ocean Drilling Program, Scientific Results, Vol. 157 25. GEOCHEMISTRY OF SIDEROMELANE AND FELSIC GLASS SHARDS IN PLEISTOCENE ASH LAYERS AT SITES 953, 954, AND 9561 Andrey A. Gurenko2 and Hans-Ulrich Schmincke2 ABSTRACT Sideromelane and felsic glass shards from unconsolidated Pleistocene volcaniclastic sediments drilled at Sites 953, 954, and 956 are thought to have derived from submarine and subaerial volcanic eruptions on Gran Canaria (Sites 953 and 954) and Tenerife (Sites 954 and 956). We analyzed these glasses by electron microprobe for major elements and sulfur, chlorine, and fluorine. Sideromelane glasses represent a spectrum from alkali basalt through basanite, hawaiite, mugearite, and tephrite to nephelinite. Felsic glasses have compositions similar to benmoreite, trachyte, and phonolite. Vesiculated mafic and felsic glass shards, which are characterized by low S and Cl concentrations (0.01−0.06 wt% S and 0.01–0.04 wt% Cl), are interpreted to have formed by pyroclastic activity on land or in shallow water and appeared to have been strongly degassed. Vesicle-free blocky glass shards having 0.05−0.13 wt% S are likely to have resulted from submarine eruptions at moderate water depths and represent undegassed or slightly degassed magmas. Cl concentrations range from 0.01 to 0.33 wt% and increase with increasing MgO, suggesting that Cl behaves as an incompatible element during magma crystallization. Concentrations of fluorine (0.04− 0.34 wt% F) are likely to represent undegassed values, and the variations in F/K ratios between 0.02 and 0.24 are believed to reflect those of parental magmas and of the mantle source. -
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. -
Nonexplosive and Explosive Magma/Wet-Sediment Interaction
Journal of Volcanology and Geothermal Research 181 (2009) 155–172 Contents lists available at ScienceDirect Journal of Volcanology and Geothermal Research journal homepage: www.elsevier.com/locate/jvolgeores Nonexplosive and explosive magma/wet-sediment interaction during emplacement of Eocene intrusions into Cretaceous to Eocene strata, Trans-Pecos igneous province, West Texas Kenneth S. Befus a,⁎, Richard E. Hanson a, Daniel P. Miggins b, John A. Breyer a, Arthur B. Busbey a a Department of Geology, Texas Christian University, Box 298830, Fort Worth, TX 76129, USA b U.S. Geological Survey, Denver Federal Center, Box 25046, Denver, CO 80225, USA article info abstract Article history: Eocene intrusion of alkaline basaltic to trachyandesitic magmas into unlithified, Upper Cretaceous Received 16 June 2008 (Maastrichtian) to Eocene fluvial strata in part of the Trans-Pecos igneous province in West Texas produced Accepted 22 December 2008 an array of features recording both nonexplosive and explosive magma/wet-sediment interaction. Intrusive Available online 13 January 2009 complexes with 40Ar/39Ar dates of ~47–46 Ma consist of coherent basalt, peperite, and disrupted sediment. Two of the complexes cutting Cretaceous strata contain masses of conglomerate derived from Eocene fluvial Keywords: deposits that, at the onset of intrusive activity, would have been N400–500 m above the present level of phreatomagmatism peperite exposure. These intrusive complexes are inferred to be remnants of diatremes that fed maar volcanoes during diatreme an early stage of magmatism in this part of the Trans-Pecos province. Disrupted Cretaceous strata along Trans-Pecos Texas diatreme margins record collapse of conduit walls during and after subsurface phreatomagmatic explosions. -
The Late Oligocene Cieneguilla Basanites, Santa Fe County
New Mexico Geological Society Downloaded from: http://nmgs.nmt.edu/publications/guidebooks/62 The late Oligocene Cieneguilla basanites, Santa Fe County: Records of early Rio Grande rift magmatism Jennifer Lindline, Michael Petronis, Rachell Pitrucha, and Salvador Sena, 2011, pp. 235-250 in: Geology of the Tusas Mountains and Ojo Caliente, Author Koning, Daniel J.; Karlstrom, Karl E.; Kelley, Shari A.; Lueth, Virgil W.; Aby, Scott B., New Mexico Geological Society 62nd Annual Fall Field Conference Guidebook, 418 p. This is one of many related papers that were included in the 2011 NMGS Fall Field Conference Guidebook. Annual NMGS Fall Field Conference Guidebooks Every fall since 1950, the New Mexico Geological Society (NMGS) has held an annual Fall Field Conference that explores some region of New Mexico (or surrounding states). Always well attended, these conferences provide a guidebook to participants. Besides detailed road logs, the guidebooks contain many well written, edited, and peer-reviewed geoscience papers. These books have set the national standard for geologic guidebooks and are an essential geologic reference for anyone working in or around New Mexico. Free Downloads NMGS has decided to make peer-reviewed papers from our Fall Field Conference guidebooks available for free download. Non-members will have access to guidebook papers two years after publication. Members have access to all papers. This is in keeping with our mission of promoting interest, research, and cooperation regarding geology in New Mexico. However, guidebook sales represent a significant proportion of our operating budget. Therefore, only research papers are available for download. Road logs, mini-papers, maps, stratigraphic charts, and other selected content are available only in the printed guidebooks. -
Icelandic Hyaloclastite Tuffs Petrophysical Properties, Alteration and Geochemical Mobility
Icelandic Hyaloclastite Tuffs Petrophysical Properties, Alteration and Geochemical Mobility Hjalti Franzson Gudmundur H. Gudfinnsson Julia Frolova Helga M. Helgadóttir Bruce Pauly Anette K. Mortensen Sveinn P. Jakobsson Prepared for National Energy Authority and Reykjavík Energy ÍSOR-2011/064 ICELAND GEOSURVEY Reykjavík: Orkugardur, Grensásvegur 9, 108 Reykjavík, Iceland - Tel.: 528 1500 - Fax: 528 1699 Akureyri: Rangárvellir, P.O. Box 30, 602 Akureyri, Iceland - Tel.: 528 1500 - Fax: 528 1599 [email protected] - www.isor.is Report Project no.: 540105 Icelandic Hyaloclastite Tuffs Petrophysical Properties, Alteration and Geochemical Mobility Hjalti Franzson Gudmundur H. Gudfinnsson Julia Frolova Helga M. Helgadóttir Bruce Pauly Anette K. Mortensen Sveinn P. Jakobsson Prepared for National Energy Authority and Reykjavík Energy ÍSOR-2011/064 December 2011 Key page Report no. Date Distribution ÍSOR-2011/064 December 2011 Open Closed Report name / Main and subheadings Number of copies Icelandic Hyaloclastite Tuffs. Petrophysical Properties, Alteration 7 and Geochemical Mobility Number of pages 103 Authors Project manager Hjalti Franzson, Gudmundur H. Gudfinnsson, Julia Frolova, Hjalti Franzson Helga M. Helgadóttir, Bruce Pauly, Anette K. Mortensen and Sveinn P. Jakobsson Classification of report Project no. 540105 Prepared for National Energy Authority and Reykjavík Energy Cooperators Moscow University, University of California in Davis, Natural History Museum in Iceland Abstract This study attempts to define the properties of hyaloclastite formations which control their petrophysical characteristics during their progressive alteration. It is based on 140 tuffaceous cores from last glaciation to 2–3 m y. The water content shows a progressive increase with alteration to about 12%, which mainly is bound in the smectite and zeolite alteration minerals. -
Josephine County, Oregon, Historical Society Document Oregonłs
Finding fossils in Oregon is not so much a question of Places to see fossils: where to look for them as where not to look. Fossils are rare John Day Fossil Beds National Monument in the High Lava Plains and High Cascades, but even there, , _ Contains a 40-million year record of plant and animal life . ·� � .11�'!]�:-.: some of the lakes are famous for their fossils. Many of the ill the John Day Basill ill central Oregon near the towns of .• .� . ' · sedimentary rocks in eastern Oregon contain fossil leaves or · ,,����<:l. · . ' · •· Dayville' Fossil, and Mitchell. The Cant Ranch Visitor ; ' " ' ' j ' .- � bones. Leaffossils are especially abundant in the - Center at Sheep Rock on Highway 19 includes museum : ,· .,, 1 • , .. rocks at the far side of the athletic · exhibits of fossils. Open every day 8:30-5. For general l· · . ., ;: . · : field at Wheeler High School ,...,..;� information, contact John Day Fossil Beds National . -- - ' '· in the town of Fossil. Monument, 420 West Main St., John Day, OR 97845, ' l-, Although it is rare to phone (503) 575-0721. find a complete Oregon Museum of Science and Industry animal fossil, a 1945 SE Water Ave., Portland, OR 97214. Open Thurs. & search of river Fri. 9:30-9; Sat. through Wed. 9:30-7(sumrner hours); beds may turn . l 9:30-5(rest of year), phone (503) 797-4000 up c h1ps or Condon Museum, University of Oregon even teeth. In Pacific Hall, Eugene, OR 97403. Open only by western appointment, phone (503) 346-4577. Oregon, the ' . ; Douglas County Museum of History and sedimentary ' r Natural History rocks that are 1 primarily off1-5 at exit 123 at Roseburg (PO Box 1550, Roseburg, marine in OR 97470).