S41598-020-76691-1 1 Vol.:(0123456789)
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
Subsidence and Growth of Pacific Cretaceous Plateaus
ELSEVIER Earth and Planetary Science Letters 161 (1998) 85±100 Subsidence and growth of Paci®c Cretaceous plateaus Garrett Ito a,Ł, Peter D. Clift b a School of Ocean and Earth Science and Technology, POST 713, University of Hawaii at Manoa, Honolulu, HI 96822, USA b Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA Received 10 November 1997; revised version received 11 May 1998; accepted 4 June 1998 Abstract The Ontong Java, Manihiki, and Shatsky oceanic plateaus are among the Earth's largest igneous provinces and are commonly believed to have erupted rapidly during the surfacing of giant heads of initiating mantle plumes. We investigate this hypothesis by using sediment descriptions of Deep Sea Drilling Project (DSDP) and Ocean Drilling Program (ODP) drill cores to constrain plateau subsidence histories which re¯ect mantle thermal and crustal accretionary processes. We ®nd that total plateau subsidence is comparable to that expected of normal sea¯oor but less than predictions of thermal models of hotspot-affected lithosphere. If crustal emplacement was rapid, then uncertainties in paleo-water depths allow for the anomalous subsidence predicted for plumes with only moderate temperature anomalies and volumes, comparable to the sources of modern-day hotspots such as Hawaii and Iceland. Rapid emplacement over a plume head of high temperature and volume, however, is dif®cult to reconcile with the subsidence reconstructions. An alternative possibility that reconciles low subsidence over a high-temperature, high-volume plume source is a scenario in which plateau subsidence is the superposition of (1) subsidence due to the cooling of the plume source, and (2) uplift due to prolonged crustal growth in the form of magmatic underplating. -
Physical Geology Unit .5
Physical geology Unit .5 Plateaus and plains Definition Plateaus.A plateau is a flat, elevated landform that rises sharply above the surrounding area on at least one side. Plateaus occur on every continent and take up a third of the Earths land. Plains. A plain is a flat, sweeping landmass that generally does not change much in elevation. Plains occur as lowlands along valleys or on the doorsteps of mountains, as coastal plains. Characteristics and types of plateaus and plains. Plateaus. A plateau is a flat, elevated landform that rises sharply above the surrounding area on at least one side. Plateaus occur on every continent and take up a third of the Earths land. They are one of the four major landforms, along with mountains, plains, and hills. There are two kinds of plateaus: dissected plateaus and volcanic plateaus. A dissected plateau forms as a result of upward movement in the Earths crust. The uplift is caused by the slow collision of tectonic plates. The Colorado Plateau, in the western United States, has been rising about .03 centimeter (.01 inch) a year for more than 10 million years. A volcanic plateau is formed by numerous small volcanic eruptions that slowly build up over time, forming a plateau from the resulting lava flows. The North Island Volcanic Plateau covers most of the central part of the North Island of New Zealand. This volcanic plateau still has three active volcanoes: Mount Tongariro, Mount Ngauruhoe, and Mount Ruapehu. Erosion can influence the shape of a plateau. Soft rock often erodes away on the top of a plateau. -
3.16 Oceanic Plateaus A.C.Kerr Cardiffuniversity,Wales,UK
3.16 Oceanic Plateaus A.C.Kerr CardiffUniversity,Wales,UK 3.16.1 INTRODUCTION 537 3.16.2 FORMATION OF OCEANIC PLATEAUS 539 3.16.3 PRESERVATIONOFOCEANIC PLATEAUS 540 3.16.4GEOCHEMISTRY OF CRETACEOUSOCEANICPLATEAUS 540 3.16.4.1 GeneralChemicalCharacteristics 540 3.16.4.2 MantlePlumeSource Regions ofOceanic Plateaus 541 3.16.4.3 Caribbean–ColombianOceanic Plateau(, 90 Ma) 544 3.16.4.4OntongJavaPlateau(, 122 and , 90 Ma) 548 3.16.5THE INFLUENCE OF CONTINENTALCRUST ON OCEANIC PLATEAUS 549 3.16.5.1 The NorthAtlantic Igneous Province ( , 60 Ma to Present Day) 549 3.16.5.2 The KerguelenIgneous Province ( , 133 Ma to Present Day) 550 3.16.6 IDENTIFICATION OF OCEANIC PLATEAUS IN THE GEOLOGICAL RECORD 551 3.16.6.1 Diagnostic FeaturesofOceanic Plateaus 552 3.16.6.2 Mafic Triassic Accreted Terranesinthe NorthAmericanCordillera 553 3.16.6.3 Carboniferous to CretaceousAccreted Oceanic Plateaus inJapan 554 3.16.7 PRECAMBRIAN OCEANICPLATEAUS 556 3.16.8ENVIRONMENTAL IMPACT OF OCEANICPLATEAU FORMATION557 3.16.8.1 Cenomanian–TuronianBoundary (CTB)Extinction Event 558 3.16.8.2 LinksbetweenCTB Oceanic PlateauVolcanism andEnvironmentalPerturbation 558 3.16.9 CONCLUDING STATEMENTS 560 REFERENCES 561 3.16.1 INTRODUCTION knowledge ofthe oceanbasins hasimproved over the last 25years,many moreoceanic plateaus Although the existence oflarge continentalflood havebeenidentified (Figure1).Coffinand basalt provinceshasbeenknownfor some Eldholm (1992) introduced the term “large igneous considerabletime, e.g.,Holmes(1918),the provinces” (LIPs) asageneric term encompassing recognition thatsimilarfloodbasalt provinces oceanic plateaus,continentalfloodbasalt alsoexist belowthe oceans isrelatively recent. In provinces,andthoseprovinceswhich form at the early 1970s increasingamounts ofevidence the continent–oceanboundary (volcanic rifted fromseismic reflection andrefraction studies margins). -
Mantle Dynamics and Characteristics of the Azores Plateau
Earth and Planetary Science Letters 362 (2013) 258–271 Contents lists available at SciVerse ScienceDirect Earth and Planetary Science Letters journal homepage: www.elsevier.com/locate/epsl Mantle dynamics and characteristics of the Azores plateau C. Adam a,n, P. Madureira a,b, J.M. Miranda c, N. Lourenc-o c,d, M. Yoshida e, D. Fitzenz a,1 a Centro de Geofı´sica de E´vora/Univ. E´vora, 7002-554 E´vora, Portugal b Estrutura de Missao~ para a Extensao~ da Plataforma Continental (EMEPC), 2770-047, Pac-o d’ Arcos, Portugal c Instituto Portugues do Mar e da Atmosfera, Lisboa, Portugal d University of Algarve, IDL, Campus de Gambelas, 8000 Faro, Portugal e Institute for Research on Earth Evolution (IFREE), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokosuka, Kanagawa 237-0061, Japan article info abstract Article history: Situated in the middle of the Atlantic Ocean, the Azores plateau is a region of elevated topography Received 25 July 2012 encompassing the triple junction between the Eurasian, Nubian and North American plates. The plateau is Received in revised form crossed by the Mid-Atlantic Ridge, and the Terceira Rift is generally thought of as its northern boundary. 2 November 2012 The origin of the plateau and of the Terceira Rift is still under debate. This region is associated with active Accepted 5 November 2012 volcanism. Geophysical data describe complex tectonic and seismic patterns. The mantle under this region Editor: T. Spohn Available online 18 January 2013 is characterized by anomalously slow seismic velocities. However, this mantle structure has not yet been used to quantitatively assess the influence of the mantle dynamics on the surface tectonics. -
Active Continental Margin
Encyclopedia of Marine Geosciences DOI 10.1007/978-94-007-6644-0_102-2 # Springer Science+Business Media Dordrecht 2014 Active Continental Margin Serge Lallemand* Géosciences Montpellier, University of Montpellier, Montpellier, France Synonyms Convergent boundary; Convergent margin; Destructive margin; Ocean-continent subduction; Oceanic subduction zone; Subduction zone Definition An active continental margin refers to the submerged edge of a continent overriding an oceanic lithosphere at a convergent plate boundary by opposition with a passive continental margin which is the remaining scar at the edge of a continent following continental break-up. The term “active” stresses the importance of the tectonic activity (seismicity, volcanism, mountain building) associated with plate convergence along that boundary. Today, people typically refer to a “subduction zone” rather than an “active margin.” Generalities Active continental margins, i.e., when an oceanic plate subducts beneath a continent, represent about two-thirds of the modern convergent margins. Their cumulated length has been estimated to 45,000 km (Lallemand et al., 2005). Most of them are located in the circum-Pacific (Japan, Kurils, Aleutians, and North, Middle, and South America), Southeast Asia (Ryukyus, Philippines, New Guinea), Indian Ocean (Java, Sumatra, Andaman, Makran), Mediterranean region (Aegea, Cala- bria), or Antilles. They are generally “active” over tens (Tonga, Mariana) or hundreds (Japan, South America) of millions of years. This longevity has consequences on their internal structure, especially in terms of continental growth by tectonic accretion of oceanic terranes, or by arc magmatism, but also sometimes in terms of continental consumption by tectonic erosion. Morphology A continental margin generally extends from the coast down to the abyssal plain (see Fig. -
Description of the Telluride Quadrangle
DESCRIPTION OF THE TELLURIDE QUADRANGLE. INTRODUCTION. along the southern base, and agricultural lands water Jura of other parts of Colorado, and follow vents from which the lavas came are unknown, A general statement of the geography, topography, have been found in valley bottoms or on lower ing them comes the Cretaceous section, from the and the lavas themselves have been examined slopes adjacent to the snow-fed streams Economic Dakota to the uppermost coal-bearing member, the only in sufficient degree to show the predominant and geology of the San Juan region of from the mountains. With the devel- imp°rtance- Colorado. Laramie. Below Durango the post-Laramie forma presence of andesites, with other types ranging opment of these resources several towns of tion, made up of eruptive rock debris and known in composition from rhyolite to basalt. Pene The term San Juan region, or simply " the San importance have been established in sheltered as the "Animas beds," rests upon the Laramie, trating the bedded series are several massive Juan," used with variable meaning by early valleys on all sides. Railroads encircle the group and is in turn overlain by the Puerco and higher bodies of often coarsely granular rocks, such as explorers, and naturally with indefinite and penetrate to some of the mining centers of Eocene deposits. gabbro and diorite, and it now seems probable limitation during the period of settle- sa^juan the the interior. Creede, Silverton, Telluride, Ouray, Structurally, the most striking feature in the that the intrusive bodies of diorite-porphyry and ment, is. now quite. -
Tectonic-Sedimentary System of the Atlantis‒Meteor Seamounts (North
ISSN 0024-4902, Lithology and Mineral Resources, 2019, Vol. 54, No. 5, pp. 374–389. © Pleiades Publishing, Inc., 2019. Russian Text © The Author(s), 2019, published in Litologiya i Poleznye Iskopaemye, 2019, No. 5. Tectonic-Sedimentary System of the Atlantis‒Meteor Seamounts (North Atlantic): Volcanism and Sedimentation in the Late Miocene‒Pliocene and Position in the Atlantic‒Arctic Rift System N. P. Chamova, *, I. E. Stukalovaa, S. Yu. Sokolova, A. A. Peivea, N. V. Gor’kovaa, A. A. Razumovskiia, M. E. Bylinskayaa, and L. A. Golovinaa aGeological Institute, Russian Academy of Sciences, Pyzhevskii per., 7, Moscow, 119017 Russia *e-mail: [email protected] Received February 19, 2019; revised February 19, 2019; accepted March 13, 2019 Abstract—The paper analyzes original data obtained on the Atlantis‒Meteor seamount system during Cruise 33 of the R/V Akademik Nikolai Strakhov in the eastern North Atlantic. This system is a volcanic rise formed on the Canary abyssal plate and represents one of the key objects for understanding the geological history of opening of the central segment of the Atlantic Ocean. Basalts, tephrites, and organogenic terrigenous lagoonal marine sediments dredged from the Atlantis, Plato, and Cruiser seamounts are considered. Petrog- raphy and compositions of the Atlantis and Cruiser basalts reflect significant differences in settings of their eruptions. Well-crystallized vesicle-free olivine basalts from the Atlantis Seamount were ejected under deep- water conditions. Glassy vesicular basalts of the Cruiser Seamount are typical of shallow subaerial eruptions. Evidence for the accumulation of tuff breccias and tuff gravelstones of the Plato Seamount in subaerial set- tings are obtained. -
From Oceanic Plateaus to Allochthonous Terranes: Numerical Modelling
Gondwana Research 25 (2014) 494–508 Contents lists available at ScienceDirect Gondwana Research journal homepage: www.elsevier.com/locate/gr From oceanic plateaus to allochthonous terranes: Numerical modelling Katharina Vogt a,⁎, Taras V. Gerya a,b a Geophysical Fluid Dynamics Group, Institute of Geophysics, Department of Earth Sciences, Swiss Federal Institute of Technology (ETH-Zurich), Sonneggstrasse, 5, 8092 Zurich, Switzerland b Adjunct Professor of Geology Department, Moscow State University, 119899 Moscow, Russia article info abstract Article history: Large segments of the continental crust are known to have formed through the amalgamation of oceanic pla- Received 29 April 2012 teaus and continental fragments. However, mechanisms responsible for terrane accretion remain poorly un- Received in revised form 25 August 2012 derstood. We have therefore analysed the interactions of oceanic plateaus with the leading edge of the Accepted 4 November 2012 continental margin using a thermomechanical–petrological model of an oceanic-continental subduction Available online 23 November 2012 zone with spontaneously moving plates. This model includes partial melting of crustal and mantle lithologies and accounts for complex rheological behaviour including viscous creep and plastic yielding. Our results in- Keywords: Crustal growth dicate that oceanic plateaus may either be lost by subduction or accreted onto continental margins. Complete Subduction subduction of oceanic plateaus is common in models with old (>40 Ma) oceanic lithosphere whereas models Terrane accretion with younger lithosphere often result in terrane accretion. Three distinct modes of terrane accretion were Oceanic plateau identified depending on the rheological structure of the lower crust and oceanic cooling age: frontal plateau accretion, basal plateau accretion and underplating plateaus. -
PDF Linkchapter
Index [Italic page numbers indicate major references] Abaco Knoll, 359 116, 304, 310, 323 Bahama Platform, 11, 329, 331, 332, Abathomphalus mayaroensis, 101 Aquia Formation, 97, 98, 124 341, 358, 360 Abbott pluton, 220 aquifers, 463, 464, 466, 468, 471, Bahama volcanic crust, 356 Abenaki Formation, 72, 74, 257, 476, 584 Bahamas basin, 3, 5, 35, 37, 39, 40, 259, 261, 369, 372, 458 Aquitaine, France, 213, 374 50 ablation, 149 Arcadia Formation, 505 Bahamas Fracture Zone, 24, 39, 40, Abyssal Plain, 445 Archaean age, 57 50, 110, 202, 349, 358, 368 Adirondack Mountains, 568 Arctic-North Atlantic rift system, 49, Bahamas Slope, 12 Afar region, Djibouti, 220, 357 50 Bahamas-Cuban Fault system, 50 Africa, 146, 229, 269, 295, 299 Ardsley, New York, 568, 577 Baja California, Mexico, 146 African continental crust, 45, 331, Argana basin, Morocco, 206 Bajocian assemblages, 20, 32 347 Argo Fan, Scotian margin, 279 Balair fault zone, 560 African Craton, 368 Argo Salt Formation, 72, 197, 200, Baltimore Canyon trough, 3, 37, 38, African margin, 45, 374 278, 366, 369, 373 40, 50, 67, 72 , 81, 101, 102, African plate, 19, 39, 44, 49 arkoses, 3 138, 139, 222, 254, 269, 360, Afro-European plate, 197 artesian aquifers, 463 366, 369, 396, 419,437 Agamenticus pluton, 220 Ashley Formation, 126 basement rocks, 74 age, 19, 208, 223 Astrerosoma, 96 carbonate deposits, 79 Agulhas Bank, 146 Atkinson Formation, 116, 117 crustal structure, 4, 5, 46 Aiken Formation, 125 Atlantic basin, 6, 9, 264 faults in, 32 Aikin, South Carolina, 515 marine physiography, 9 geologic -
Bering Sea in Summer of 1955
OCEANOGRAPHIC CONDITIONS OF THE WHALING GROUNDS IN THE WATERS ADJACENT TO ALEUTIAN ISLANDS AND THE BERING SEA IN SUMMER OF 1955 KEIJI NASU INTRODUCTION The present paper gives the outline of the results investigated by Japa nese research members in the waters adjacent to Aleutian Islands and the Bering Sea during the Whaling Survey including whale-marking ex periment in the summer of 1955 on boad of the "Konan-maru No. 5 ", be longing to the Nippon Suisan Co. Ltd. During the season, 73 Stations were occupied by the boat as shown in figure 1, the observed data at these stations are compiled with respect to the oceanographic elements such as water temperature, salinity (chlorinity), transparency of the sea water, colour of the sea water, dissolved oxygen, planktons, and other sea living organisms sampled from various depths, and also with the weather elements such as air temperature, sea-fog etc. Above materials are collected on board by the author and Takehiko Kawakami of the Japa nese Fisheries Agency. The author wishes to express his hearty thanks to Dr. Michitaka Uda, Professor of the Tokyo University of Fisheries and also to Mr. Makoto Ishino for their instructions and aids given during the preparation of this report. WATER TEMPERATURE AND SALINITY AT THE SEA SURF ACE The surface temperature in the period during the survey from early July to late September in the Bering Sea and the southern Aleutian Waters in the North Pacific vary from 11.8°C at its maximum to the lowest value 6.5°C. In general the isothermal lines run parallel to the Aleutian Islands from west to east. -
98-031 Oceanus F/W 97 Final
A hotspot created the island of Iceland and its characteristic volcanic landscape. Hitting the Hotspots Hotspots are rela- tively small regions on the earth where New Studies Reveal Critical Interactions unusually hot rocks rise from deep inside Between Hotspots and Mid-Ocean Ridges the mantle layer. Jian Lin Associate Scientist, Geology & Geophysics Department he great volcanic mid-ocean ridge system hotspots may play a critical role in shaping the stretches continuously around the globe for seafloor—acting in some cases as strategically T 60,000 kilometers, nearly all of it hidden positioned supply stations that fuel the lengthy beneath the world’s oceans. In some places, how- mid-ocean ridges with magma. ever, mid-ocean ridge volcanoes are so massive that Studies of ridge-hotspot interactions received a they emerge above sea level to create some of the major boost in 1995 when the US Navy declassified most spectacular islands on our planet. Iceland, the gravity data from its Geosat satellite, which flew Azores, and the Galápagos are examples of these from 1985 to 1990. The satellite recorded in unprec- “hotspot” islands—so named because they are edented detail the height of the ocean surface. With believed to form above small regions scattered accuracy within 5 centimeters, it revealed small around the earth where unusually hot rocks rise bumps and dips created by the gravitational pull of from deep inside the mantle layer. dense underwater mountains and valleys. Research- But hotspots may not be such isolated phenom- ers often use precise gravity measurements to probe ena. Exciting advances in satellite oceanography, unseen materials below the ocean floor. -
Hotspots and Mantle Plumes Pdf
Hotspots and mantle plumes pdf Continue The mantle feathers area is hot, upwelling the mantle. A hot spot develops above the train. Magma, generated by a hot spot, rises through rigid slabs of the lithosphere and produces active volcanoes on the Earth's surface. As ocean volcanoes move away from the hotspot, they cool and subside, producing old islands, atolls and seamounts. As continental volcanoes move away from the hotspot, they cool, subside and die out. Hot spots are places inside the mantle where stones melt to generate magma. The presence of a hot spot stems from abnormal volcanism (i.e. not on the plate boundary) such as Hawaiian volcanoes within the Pacific Plate. The Hawaiian hotspot has been active for at least 70 million years, producing a volcanic chain that stretches for 3,750 miles (6,000 km) across the Pacific Northwest. Hot spots also develop under continents. Yellowstone hot spot has been active for at least 15 million years, producing a chain of caldera and volcanic features along the plains of the Snake River, which stretches 400 miles (650 km) west from northwest Wyoming to the Idaho-Oregon border. Keep in mind, however, that these are just theories. No one knows the answer. The honest answer is that many people are working on it but have not yet come up with an answer. Graphics After Morgan, J., 1971, Convection feathers in the lower mantle: Nature, art 230, p. 42-43. Volcanic regions, which are thought to feed on the underlying mantle, are abnormally hot compared to the surrounding mantle Diagram, showing a cross-section across the Earth's lithosphere (yellow) with magma rising from the mantle (red).