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Assembly, Configuration, and Break-Up History of Rodinia
Author's personal copy Available online at www.sciencedirect.com Precambrian Research 160 (2008) 179–210 Assembly, configuration, and break-up history of Rodinia: A synthesis Z.X. Li a,g,∗, S.V. Bogdanova b, A.S. Collins c, A. Davidson d, B. De Waele a, R.E. Ernst e,f, I.C.W. Fitzsimons g, R.A. Fuck h, D.P. Gladkochub i, J. Jacobs j, K.E. Karlstrom k, S. Lu l, L.M. Natapov m, V. Pease n, S.A. Pisarevsky a, K. Thrane o, V. Vernikovsky p a Tectonics Special Research Centre, School of Earth and Geographical Sciences, The University of Western Australia, Crawley, WA 6009, Australia b Department of Geology, Lund University, Solvegatan 12, 223 62 Lund, Sweden c Continental Evolution Research Group, School of Earth and Environmental Sciences, University of Adelaide, Adelaide, SA 5005, Australia d Geological Survey of Canada (retired), 601 Booth Street, Ottawa, Canada K1A 0E8 e Ernst Geosciences, 43 Margrave Avenue, Ottawa, Canada K1T 3Y2 f Department of Earth Sciences, Carleton U., Ottawa, Canada K1S 5B6 g Tectonics Special Research Centre, Department of Applied Geology, Curtin University of Technology, GPO Box U1987, Perth, WA 6845, Australia h Universidade de Bras´ılia, 70910-000 Bras´ılia, Brazil i Institute of the Earth’s Crust SB RAS, Lermontova Street, 128, 664033 Irkutsk, Russia j Department of Earth Science, University of Bergen, Allegaten 41, N-5007 Bergen, Norway k Department of Earth and Planetary Sciences, Northrop Hall University of New Mexico, Albuquerque, NM 87131, USA l Tianjin Institute of Geology and Mineral Resources, CGS, No. -
1 John A. Tarduno
JOHN A. TARDUNO January, 2016 Professor of Geophysics Tel: 585-275-5713 Department of Earth and Environmental Sciences Fax: 585-244-5689 University of Rochester, Rochester, NY 14627 Email: [email protected] USA http://www.ees.rochester.edu/people/faculty/tarduno_john Academic Career: 2005-present Professor of Physics and Astronomy, University of Rochester, Rochester, NY. 2000-present Professor of Geophysics, University of Rochester, Rochester, NY. 1998-2006 Chair, Department of Earth and Environmental Sciences 1996 Associate Professor of Geophysics, University of Rochester, Rochester, NY. 1993 Assistant Professor of Geophysics, University of Rochester, Rochester, NY. 1990 Assistant Research Geophysicist, Scripps Institution of Oceanography, La Jolla, Ca. 1989 National Science Foundation Postdoctoral Fellow, ETH, Zürich, Switzerland 1988 JOI/USSAC Ocean Drilling Fellow, Stanford University, Stanford, Ca. 1987 Ph.D. (Geophysics), Stanford University, Stanford, Ca. 1987 M.S. (Geophysics) Stanford University, Stanford Ca. 1983 B.S. (Geophysics) Lehigh University, Bethlehem Pa. Honors and Awards: Phi Beta Kappa (1983) Fellow, Geological Society of America (1998) JOI/USSAC Distinguished Lecturer (2000-2001) Goergen Award for Distinguished Achievement and Artistry in Undergraduate Teaching (2001) Fellow, American Association for the Advancement of Science (2003) American Geophysical Union/Geomagnetism and Paleomagnetism Section Bullard Lecturer (2004) Fellow, John Simon Guggenheim Foundation (2006-2007) Edward Peck Curtis Award for -
Geophysical Field Mapping
Presented at Short Course IX on Exploration for Geothermal Resources, organized by UNU-GTP, GDC and KenGen, at Lake Bogoria and Lake Naivasha, Kenya, Nov. 2-23, 2014. Kenya Electricity Generating Co., Ltd. GEOPHYSICAL FIELD MAPPING Anastasia W. Wanjohi, Kenya Electricity Generating Company Ltd. Olkaria Geothermal Project P.O. Box 785-20117, Naivasha KENYA [email protected] or [email protected] ABSTRACT Geophysics is the study of the earth by the quantitative observation of its physical properties. In geothermal geophysics, we measure the various parameters connected to geological structure and properties of geothermal systems. Geophysical field mapping is the process of selecting an area of interest and identifying all the geophysical aspects of the area with the purpose of preparing a detailed geophysical report. The objective of geophysical field work is to understand all physical parameters of a geothermal field and be able to relate them with geological phenomenons and come up with plausible inferences about the system. Four phases are involved and include planning/desktop studies, reconnaissance, actual data aquisition and report writing. Equipments must be prepared and calibrated well. Geophysical results should be processed, analysed and presented in the appropriate form. A detailed geophysical report should be compiled. This paper presents the reader with an overview of how to carry out geophysical mapping in a geothermal field. 1. INTRODUCTION Geophysics is the study of the earth by the quantitative observation of its physical properties. In geothermal geophysics, we measure the various parameters connected to geological structure and properties of geothermal systems. In lay man’s language, geophysics is all about x-raying the earth and involves sending signals into the earth and monitoring the outcome or monitoring natural signals from the earth. -
Mantle Flow Through the Northern Cordilleran Slab Window Revealed by Volcanic Geochemistry
Downloaded from geology.gsapubs.org on February 23, 2011 Mantle fl ow through the Northern Cordilleran slab window revealed by volcanic geochemistry Derek J. Thorkelson*, Julianne K. Madsen, and Christa L. Sluggett Department of Earth Sciences, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada ABSTRACT 180°W 135°W 90°W 45°W 0° The Northern Cordilleran slab window formed beneath west- ern Canada concurrently with the opening of the Californian slab N 60°N window beneath the southwestern United States, beginning in Late North Oligocene–Miocene time. A database of 3530 analyses from Miocene– American Holocene volcanoes along a 3500-km-long transect, from the north- Juan Vancouver Northern de ern Cascade Arc to the Aleutian Arc, was used to investigate mantle Cordilleran Fuca conditions in the Northern Cordilleran slab window. Using geochemi- Caribbean 30°N Californian Mexico Eurasian cal ratios sensitive to tectonic affi nity, such as Nb/Zr, we show that City and typical volcanic arc compositions in the Cascade and Aleutian sys- Central African American Cocos tems (derived from subduction-hydrated mantle) are separated by an Pacific 0° extensive volcanic fi eld with intraplate compositions (derived from La Paz relatively anhydrous mantle). This chemically defi ned region of intra- South Nazca American plate volcanism is spatially coincident with a geophysical model of 30°S the Northern Cordilleran slab window. We suggest that opening of Santiago the slab window triggered upwelling of anhydrous mantle and dis- Patagonian placement of the hydrous mantle wedge, which had developed during extensive early Cenozoic arc and backarc volcanism in western Can- Scotia Antarctic Antarctic 60°S ada. -
Geological Evolution of the Red Sea: Historical Background, Review and Synthesis
See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/277310102 Geological Evolution of the Red Sea: Historical Background, Review and Synthesis Chapter · January 2015 DOI: 10.1007/978-3-662-45201-1_3 CITATIONS READS 6 911 1 author: William Bosworth Apache Egypt Companies 70 PUBLICATIONS 2,954 CITATIONS SEE PROFILE Some of the authors of this publication are also working on these related projects: Near and Middle East and Eastern Africa: Tectonics, geodynamics, satellite gravimetry, magnetic (airborne and satellite), paleomagnetic reconstructions, thermics, seismics, seismology, 3D gravity- magnetic field modeling, GPS, different transformations and filtering, advanced integrated examination. View project Neotectonics of the Red Sea rift system View project All content following this page was uploaded by William Bosworth on 28 May 2015. The user has requested enhancement of the downloaded file. All in-text references underlined in blue are added to the original document and are linked to publications on ResearchGate, letting you access and read them immediately. Geological Evolution of the Red Sea: Historical Background, Review, and Synthesis William Bosworth Abstract The Red Sea is part of an extensive rift system that includes from south to north the oceanic Sheba Ridge, the Gulf of Aden, the Afar region, the Red Sea, the Gulf of Aqaba, the Gulf of Suez, and the Cairo basalt province. Historical interest in this area has stemmed from many causes with diverse objectives, but it is best known as a potential model for how continental lithosphere first ruptures and then evolves to oceanic spreading, a key segment of the Wilson cycle and plate tectonics. -
A Continuous Plate-Tectonic Model Using Geophysical Data to Estimate
GEOPHYSICAL JOURNAL INTERNATIONAL, 133, 379–389, 1998 1 A continuous plate-tectonic model using geophysical data to estimate plate margin widths, with a seismicity based example Caroline Dumoulin1, David Bercovici2, Pal˚ Wessel Department of Geology & Geophysics, School of Ocean and Earth Science and Technology, University of Hawaii, Honolulu, 96822, USA Summary A continuous kinematic model of present day plate motions is developed which 1) provides more realistic models of plate shapes than employed in the original work of Bercovici & Wessel [1994]; and 2) provides a means whereby geophysical data on intraplate deformation is used to estimate plate margin widths for all plates. A given plate’s shape function (which is unity within the plate, zero outside the plate) can be represented by analytic functions so long as the distance from a point inside the plate to the plate’s boundary can be expressed as a single valued function of azimuth (i.e., a single-valued polar function). To allow sufficient realism to the plate boundaries, without the excessive smoothing used by Bercovici and Wessel, the plates are divided along pseudoboundaries; the boundaries of plate sections are then simple enough to be modelled as single-valued polar functions. Moreover, the pseudoboundaries have little or no effect on the final results. The plate shape function for each plate also includes a plate margin function which can be constrained by geophysical data on intraplate deformation. We demonstrate how this margin function can be determined by using, as an example data set, the global seismicity distribution for shallow (depths less than 29km) earthquakes of magnitude greater than 4. -
Satellite Measured Ionospheric Magnetic Field Variations Over Natural Hazards Sites
remote sensing Article Satellite Measured Ionospheric Magnetic Field Variations over Natural Hazards Sites Christoph Schirninger 1,†, Hans U. Eichelberger 1,*,†, Werner Magnes 1 , Mohammed Y. Boudjada 1,†, Konrad Schwingenschuh 1,†, Andreas Pollinger 1, Bruno P. Besser 1, Pier F. Biagi 2 , Maria Solovieva 3, Jindong Wang 4, Bingjun Cheng 4, Bin Zhou 4, Xuhui Shen 5, Magda Delva 1 and Roland Lammegger 6 1 Space Research Institute, Austrian Academy of Sciences, Schmiedlstraße 6, 8042 Graz, Austria; [email protected] (C.S.); [email protected] (W.M.); [email protected] (M.Y.B.); [email protected] (K.S.); [email protected] (A.P.); [email protected] (B.P.B.); [email protected] (M.D.) 2 Department of Physics, University of Bari, 70126 Bari, Italy; [email protected] 3 Schmidt Institute of Physics of the Earth, Russian Academy of Sciences, 123995 Moscow, Russia; [email protected] 4 National Space Science Center, Chinese Academy of Sciences, Beijing 100190, China; [email protected] (J.W.); [email protected] (B.C.); [email protected] (B.Z.) 5 National Institute of Natural Hazards, MEMC, Beijing 100085, China; [email protected] 6 Institute of Experimental Physics, Graz University of Technology, 8010 Graz, Austria; [email protected] * Correspondence: [email protected] † These authors contributed equally to this work. Citation: Schirninger, C.; Eichelberger, H.U.; Magnes, W.; Abstract: Processes and threats related to natural hazards play an important role in the evolution of Boudjada, M.Y.; Schwingenschuh, K.; the Earth and in human history. -
Environmental Geology Chapter 2 -‐ Plate Tectonics and Earth's Internal
Environmental Geology Chapter 2 - Plate Tectonics and Earth’s Internal Structure • Earth’s internal structure - Earth’s layers are defined in two ways. 1. Layers defined By composition and density o Crust-Less dense rocks, similar to granite o Mantle-More dense rocks, similar to peridotite o Core-Very dense-mostly iron & nickel 2. Layers defined By physical properties (solid or liquid / weak or strong) o Lithosphere – (solid crust & upper rigid mantle) o Asthenosphere – “gooey”&hot - upper mantle o Mesosphere-solid & hotter-flows slowly over millions of years o Outer Core – a hot liquid-circulating o Inner Core – a solid-hottest of all-under great pressure • There are 2 types of crust ü Continental – typically thicker and less dense (aBout 2.8 g/cm3) ü Oceanic – typically thinner and denser (aBout 2.9 g/cm3) The Moho is a discontinuity that separates lighter crustal rocks from denser mantle below • How do we know the Earth is layered? That knowledge comes primarily through the study of seismology: Study of earthquakes and seismic waves. We look at the paths and speeds of seismic waves. Earth’s interior boundaries are defined by sudden changes in the speed of seismic waves. And, certain types of waves will not go through liquids (e.g. outer core). • The face of Earth - What we see (Observations) Earth’s surface consists of continents and oceans, including mountain belts and “stable” interiors of continents. Beneath the ocean, there are continental shelfs & slopes, deep sea basins, seamounts, deep trenches and high mountain ridges. We also know that Earth is dynamic and earthquakes and volcanoes are concentrated in certain zones. -
Plate Tectonics and the Cycling of Earth Materials
Plate Tectonics and the cycling of Earth materials Plate tectonics drives the rock cycle: the movement of rocks (and the minerals that comprise them, and the chemical elements that comprise them) from one reservoir to another Arrows are pathways, or fluxes, the I,M.S rocks are processes that “reservoirs” - places move material from one reservoir where material is temporarily stored to another We need to be able to identify these three types of rocks. Why? They convey information about the geologic history of a region. What types of environments are characterized by the processes that produce igneous rocks? What types of environments are preserved by the accumulation of sediment? What types of environments are characterized by the tremendous heat and pressure that produces metamorphic rocks? How the rock cycle integrates into plate tectonics. In order to understand the concept that plate tectonics drives the rock cycle, we need to understand what the theory of plate tectonics says about how the earth works The major plates in today’s Earth (there have been different plates in the Earth’s past!) What is a “plate”? The “plate” of plate tectonics is short for “lithospheric plate” - - the outermost shell of the Earth that behaves as a rigid substance. What does it mean to behave as a rigid substance? The lithosphere is ~150 km thick. It consists of the crust + the uppermost mantle. Below the lithosphere the asthenosphere behaves as a ductile layer: one that flows when stressed It means that when the substance undergoes stress, it breaks (a non-rigid, or ductile, substance flows when stressed; for example, ice flows; what we call a glacier) Since the plates are rigid, brittle 150km thick slabs of the earth, there is a lot of “action”at the edges where they abut other plates We recognize 3 types of plate boundaries, or edges. -
TECTONOPHYSICS the International Journal of Integrated Solid Earth Sciences
TECTONOPHYSICS The International Journal of Integrated Solid Earth Sciences AUTHOR INFORMATION PACK TABLE OF CONTENTS XXX . • Description p.1 • Audience p.2 • Impact Factor p.2 • Abstracting and Indexing p.2 • Editorial Board p.2 • Guide for Authors p.4 ISSN: 0040-1951 DESCRIPTION . The prime focus of Tectonophysics will be high-impact original research and reviews in the fields of kinematics, structure, composition, and dynamics of the solid earth at all scales. Tectonophysics particularly encourages submission of papers based on the integration of a multitude of geophysical, geological, geochemical, geodynamic, and geotectonic methods with focus on: • Kinematics and deformation of the lithosphere based on space geodesy (e.g. GPS, InSAR), neoteoctonic studies, tectonic geomorphology, and geochronology; • Structure, composition, and thermal state of the crust and mantle and their evolution in various time scales based on geophysical and geochemical studies; • Structural geology, folding, faulting, fracturing, analysis of stress and strain, and rock mechanics; • Orogenesis, tectonism, thermochronology, surficial processes, land-climate interactions, and Lithospheric-asthenospheric interactions; • Active tectonics, seismology, mechanisms of earthquakes and volcanism, geological hazards and their societal impacts; • Rheology and numerical modelling of geodynamic processes; • Laboratory measurements of physical and chemical parameters of crustal and mantle rocks, and their application to geophysics and petrology; • Innovative development, including testing, of new methods in geophysics and geodynamics. Tectonophysics welcomes contributions of three types: • Regular papers. • Fast track papers for short, innovative rapid communication, which will usually be reviewed within three weeks after submission. More information about this paper type can be found within the Guide for Authors. • Comprehensive invited review articles which provide an overview of significant subjects. -
Seafloor Spreading and Plate Tectonics
OCN 201: Seafloor Spreading and Plate Tectonics I Revival of Continental Drift Theory • Kiyoo Wadati (1935) speculated that earthquakes and volcanoes may be associated with continental drift. • Hugo Benioff (1940) plotted locations of deep earthquakes at edge of Pacific “Ring of Fire”. • Earthquakes are not randomly distributed but instead coincide with mid-ocean ridge system. • Evidence of polar wandering. Revival of Continental Drift Theory Wegener’s theory was revived in the 1950’s based on paleomagnetic evidence for “Polar Wandering”. Earth’s Magnetic Field Earth’s magnetic field simulates a bar magnet, but it is caused by A bar magnet with Fe filings convection of liquid Fe in Earth’s aligning along the “lines” of the outer core: the Geodynamo. magnetic field A moving electrical conductor induces a magnetic field. Earth’s magnetic field is toroidal, or “donut-shaped”. A freely moving magnet lies horizontal at the equator, vertical at the poles, and points toward the “North” pole. Paleomagnetism in Rocks • Magnetic minerals (e.g. Magnetite, Fe3 O4 ) in rocks align with Earth’s magnetic field when rocks solidify. • Magnetic alignment is “frozen in” and retained if rock is not subsequently heated. • Can use paleomagnetism of ancient rocks to determine: --direction and polarity of magnetic field --paleolatitude of rock --apparent position of N and S magnetic poles. Apparent Polar Wander Paths • Geomagnetic poles 200 had apparently 200 100 “wandered” 100 systematically with time. • Rocks from different continents gave different paths! Divergence increased with age of rocks. 200 100 Apparent Polar Wander Paths 200 200 100 100 Magnetic poles have never been more the 20o from geographic poles of rotation; rest of apparent wander results from motion of continents! For a magnetic compass, the red end of the needle points to: A. -
Plate Tectonics
Plate tectonics tive motion determines the type of boundary; convergent, divergent, or transform. Earthquakes, volcanic activity, mountain-building, and oceanic trench formation occur along these plate boundaries. The lateral relative move- ment of the plates typically varies from zero to 100 mm annually.[2] Tectonic plates are composed of oceanic lithosphere and thicker continental lithosphere, each topped by its own kind of crust. Along convergent boundaries, subduction carries plates into the mantle; the material lost is roughly balanced by the formation of new (oceanic) crust along divergent margins by seafloor spreading. In this way, the total surface of the globe remains the same. This predic- The tectonic plates of the world were mapped in the second half of the 20th century. tion of plate tectonics is also referred to as the conveyor belt principle. Earlier theories (that still have some sup- porters) propose gradual shrinking (contraction) or grad- ual expansion of the globe.[3] Tectonic plates are able to move because the Earth’s lithosphere has greater strength than the underlying asthenosphere. Lateral density variations in the mantle result in convection. Plate movement is thought to be driven by a combination of the motion of the seafloor away from the spreading ridge (due to variations in topog- raphy and density of the crust, which result in differences in gravitational forces) and drag, with downward suction, at the subduction zones. Another explanation lies in the different forces generated by the rotation of the globe and the tidal forces of the Sun and Moon. The relative im- portance of each of these factors and their relationship to each other is unclear, and still the subject of much debate.