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Hydrothermal Alteration of a Supra-Subduction Zone Ophiolite Analog, Tonga
AN ABSTRACT OF THE THESIS OF Melanie C. Kelman for the degree of Master of Science in Geology presented on May 29, 1998. Title: Hydrothermal Alteration of a Supra-Subduction Zone Ophiolite Analog, Tonga. Southwest Pacific. Abstract approved: Redacted for Privacy Sherman Bloomer The basement of the Tonga intraoceanic forearc comprises Eocene arc volcanic crust formed during the earliest phases of subduction. Volcanic rocks recovered from the forearc include boninites and arc tholeiites, apparently erupted into and upon older mid- oceanic ridge tholeiites. Rock assemblages suggest that the forearc basement is a likely analog for large supra-subduction zone (SSZ) ophiolites not only in structure and Ethology, but also in the style of hydrothermal alteration. Dredged volcanic samples from the central Tonga forearc (20-24° S) exhibit the effects of seafloor weathering, low (<200°C, principally <100°C) alteration, and high temperature (>200°C) alteration. Tholeiites and arc tholeiites are significantly more altered than boninites. Seafloor weathering is due to extensive interaction with cold oxidizing seawater, and is characterized by red-brown staining and the presence of Fe- oxyhydroxides. Low temperature alteration is due to circulation of evolving seawater- derived fluids through the volcanic section until fluid pathways were closed by secondary mineral precipitation. Low temperature alteration is characterized by smectites, celadonite, phillipsite, mixed-layer smectite/chlorite, carbonates, and silica. All phases fill veins and cavities; clay minerals and silica also replace the mesostasis and groundmass phases. Low temperature alteration enriches the bulk rock in K, Ba, and Na, and mobilizes other elements to varying extents. The few high temperature samples are characterized by mobilizes other elements to varying extents. -
Characterizing the Evolution of Slab Inputs
University of South Florida Scholar Commons Graduate Theses and Dissertations Graduate School 3-23-2017 Characterizing the Evolution of Slab Inputs in the Earliest Stages of Subduction: Preliminary Evidence from the Fluid-Mobile Element (B, Cs, As, Li) Systematics of Izu-Bonin Boninitic Glasses Recovered During IODP Expedition 352 Keir Aavon Sanatan University of South Florida, [email protected] Follow this and additional works at: http://scholarcommons.usf.edu/etd Part of the Geochemistry Commons, and the Geology Commons Scholar Commons Citation Sanatan, Keir Aavon, "Characterizing the Evolution of Slab Inputs in the Earliest Stages of Subduction: Preliminary Evidence from the Fluid-Mobile Element (B, Cs, As, Li) Systematics of Izu-Bonin Boninitic Glasses Recovered During IODP Expedition 352" (2017). Graduate Theses and Dissertations. http://scholarcommons.usf.edu/etd/6755 This Thesis is brought to you for free and open access by the Graduate School at Scholar Commons. It has been accepted for inclusion in Graduate Theses and Dissertations by an authorized administrator of Scholar Commons. For more information, please contact [email protected]. Characterizing the Evolution of Slab Inputs in the Earliest Stages of Subduction: Preliminary Evidence from the Fluid-Mobile Element (B, Cs, As, Li) Systematics of Izu-Bonin Boninitic Glasses Recovered During IODP Expedition 352 by Keir Aavon Sanatan A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Geology School of Geosciences College of Arts and Sciences University of South Florida Major Professor: Jeffrey G. Ryan, Ph.D. Zachary D. Atlas, Ph.D. Aurelie Germa, Ph.D. Date of Approval: March 24, 2017 Keywords: Boninites, Fluid-mobile elements, Izu-Bonin-Mariana, Laser ablation, Subduction initiation, Volcanic glass Copyright © 2017, Keir Aavon Sanatan TABLE OF CONTENTS List of Tables ................................................................................................................................. -
Boninite Volcanic Rocks from the Mélange of NW Dinaric-Vardar Ophiolite Zone (Mt
Mineralogy and Petrology https://doi.org/10.1007/s00710-018-0637-0 ORIGINAL PAPER Boninite volcanic rocks from the mélange of NW Dinaric-Vardar ophiolite zone (Mt. Medvednica, Croatia) – record of Middle to Late Jurassic arc-forearc system in the Tethyan subduction factory Damir Slovenec1 & Branimir Šegvić2 Received: 13 September 2017 /Accepted: 17 September 2018 # Springer-Verlag GmbH Austria, part of Springer Nature 2018 Abstract In the Late Jurassic to Early Cretaceous ophiolite mélange from the Mt. Medvednica (Vardar Ocean) blocks of boninite rocks have been documented. They emerge as massive lavas made of augite, spinel, albite and secondary hydrous silicates (e.g., chlorite, epidote, prehnite, and pumpellyite). An established crystallization sequence (spinel→clinopyroxene→plagioclase ±Fe-Ti oxides) was found to be typical for the boninite series from the suprasubduction zones (SSZ). Augite crystallization temperatures and low pressures of ~1048 to 1260 °C and ~0.24 to 0.77 GPa, respectively, delineated the SSZ mantle wedge as a plausible source of boninite parental lavas. Their whole-rock geochemistry is characterised by low Ti, P2O5, Zr, Y, high-silica, and high Mg# and Cr# values. Low and U-shaped REE profiles are consistent with the negative Nb-Ta, P and Ti anomalies indicative for SSZ. Thorium and LILE enrichment, and very low initial Nd-isotopic values (εNd(T = 150 Ma) +0.49to+1.27)actas vestiges of mantle-wedge metasomatism. The mantle source was likely depleted by the MORB and IAT melt extraction and was contemporaneously affected by subduction fluids, prior to the large-scale adiabatic melting of the mantle hanging wall. -
EGU2017-16685, 2017 EGU General Assembly 2017 © Author(S) 2017
Geophysical Research Abstracts Vol. 19, EGU2017-16685, 2017 EGU General Assembly 2017 © Author(s) 2017. CC Attribution 3.0 License. From rifting to spreading - seismic structure of the rifted western Mariana extinct arc and the ParceVela back-arc basin Ingo Grevemeyer (1), Shuichi Kodaira (2), Gou Fujie (2), and Narumi Takahashi (2) (1) GEOMAR Helmholtz Centre of Ocean Research, RD4 - Marine Geodynamics, Kiel, Germany ([email protected]), (2) Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokohama, Japan The proto Izu-Ogasawara (Bonin)-Mariana (IBM) Island arc was created when subduction of the Pacific plate be- gan during the Eocene. Today, the Kyushu-Palau Ridge (KPR) at the centre of the Philippine Sea and the western Mariana Ridge (WMR) are considered to be a remnant of the proto IBM Island arc. The KPR and WMR were separated when back-arc spreading began at 30 to 29 Ma in the Shikoku Basin and ParceVela Basin (PVB). Vol- canic activity along the arcs diminished at 27 Ma and there is little evidence of volcanic activity between 23–17 Ma. Arc volcanism was reactivated at ∼15 Ma, when the opening of the Shikoku Basin and PVB ceased. At about 5 Ma the Mariana Basin opened, rifting the WMR from the Mariana arc. Here, we report results from the seismic refraction and wide-angle profile MR101c shot in summer of 2003 by the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) aboard the RV KAIYO during the cruise KY03-06, extending from the PVB across the WMR and terminating just to the east of the WMR. -
Foreland-Forearc Collisional Granitoid and Mafic Magmatism Caused By
Foreland-forearc collisional granitoid and ma®c magmatism caused by lower-plate lithospheric slab breakoff: The Acadian of Maine, and other orogens A. Schoonmaker Department of Geology, University of Vermont, Burlington, Vermont 05405, USA W.S.F. Kidd Earth and Atmospheric Sciences, University at Albany, Albany, New York 12222, USA D.C. Bradley U.S. Geological Survey, 4200 University Drive, Anchorage, Alaska 99508, USA ABSTRACT canic belt. This model (Fig. 1) was elaborated on in Bradley et al. During collisional convergence, failure in extension of the lith- (1996), Robinson et al. (1998), Bradley and Tucker (2002), and Begeal osphere of the lower plate due to slab pull will reduce the thickness et al. (2004). Similarly, Sacks and Secor (1990) suggested lithospheric or completely remove lower-plate lithosphere and cause decom- necking to explain early granitic magmatism in the lower plate of the pression melting of the asthenospheric mantle; magmas from this southern Appalachian system during the Alleghenian orogeny. These source may subsequently provide enough heat for substantial par- models propose detachment of sections of the underthrust lower plate tial melting of crustal rocks under or beyond the toe of the colli- during the early orogenic stages of the subduction of a passive margin, sional accretionary system. In central Maine, United States, this rather than later, as proposed by Bird (1978) for the Himalaya, when type of magmatism is ®rst apparent in the Early Devonian West signi®cant lithospheric thickening and overthrusting has occurred. Branch Volcanics and equivalent ma®c volcanics, in the slightly younger voluminous ma®c/silicic magmatic event of the Moxie ACADIAN OF CENTRAL MAINEÐGEOLOGY OF THE Gabbro±Katahdin batholith and related ignimbrite volcanism, and CHESUNCOOK DOME in other Early Devonian granitic plutons. -
Geology of the Eoarchean, >3.95 Ga, Nulliak Supracrustal
ÔØ ÅÒÙ×Ö ÔØ Geology of the Eoarchean, > 3.95 Ga, Nulliak supracrustal rocks in the Saglek Block, northern Labrador, Canada: The oldest geological evidence for plate tectonics Tsuyoshi Komiya, Shinji Yamamoto, Shogo Aoki, Yusuke Sawaki, Akira Ishikawa, Takayuki Tashiro, Keiko Koshida, Masanori Shimojo, Kazumasa Aoki, Kenneth D. Collerson PII: S0040-1951(15)00269-3 DOI: doi: 10.1016/j.tecto.2015.05.003 Reference: TECTO 126618 To appear in: Tectonophysics Received date: 30 December 2014 Revised date: 30 April 2015 Accepted date: 17 May 2015 Please cite this article as: Komiya, Tsuyoshi, Yamamoto, Shinji, Aoki, Shogo, Sawaki, Yusuke, Ishikawa, Akira, Tashiro, Takayuki, Koshida, Keiko, Shimojo, Masanori, Aoki, Kazumasa, Collerson, Kenneth D., Geology of the Eoarchean, > 3.95 Ga, Nulliak supracrustal rocks in the Saglek Block, northern Labrador, Canada: The oldest geological evidence for plate tectonics, Tectonophysics (2015), doi: 10.1016/j.tecto.2015.05.003 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. ACCEPTED MANUSCRIPT Geology of the Eoarchean, >3.95 Ga, Nulliak supracrustal rocks in the Saglek Block, northern Labrador, Canada: The oldest geological evidence for plate tectonics Tsuyoshi Komiya1*, Shinji Yamamoto1, Shogo Aoki1, Yusuke Sawaki2, Akira Ishikawa1, Takayuki Tashiro1, Keiko Koshida1, Masanori Shimojo1, Kazumasa Aoki1 and Kenneth D. -
Geochemistry and Isotopic Signatures of Metavolcanic and Metaplutonic
Precambrian Research 292 (2017) 350–377 Contents lists available at ScienceDirect Precambrian Research journal homepage: www.elsevier.com/locate/precamres Geochemistry and isotopic signatures of metavolcanic and metaplutonic rocks of the Faina and Serra de Santa Rita greenstone belts, Central Brazil: Evidences for a Mesoarchean intraoceanic arc ⇑ Caio César Aguiar Borges a, , Catarina Labouré Bemfica Toledo a, Adalene Moreira Silva a, Farid Chemale Junior b, Hardy Jost a, Cristiano de Carvalho Lana c a Universidade de Brasília, Instituto de Geociências, 70910-900 Brasília, DF, Brazil b Universidade do Vale do Rio dos Sinos, Departamento de Geologia, 93022-000 São Leopoldo, RS, Brazil c Escola de Minas de Ouro Preto, Departamento de Geologia, 35400-000 Ouro Preto, MG, Brazil article info abstract Article history: The Archean-Paleoproterozoic Terrane of Goiás, Central Brazil, is an allochthonous block within the Received 23 May 2016 Neoproterozoic Tocatins Province and consists of an association of Archean TTG complexes and gold- Revised 20 February 2017 bearing Archean-Paleoproterozoic greenstone belts. The Faina and Serra Santa Rita greenstone belts, Accepted 22 February 2017 located in the southern portion of the terrane, are investigated using geochemistry and isotope geology Available online 24 February 2017 to establish the time of magmatism and tectonic environment. Our data show that the ultramafic rocks have some chemical characteristics similar to modern boninites, whereas the amphibolites are subdi- Keywords: vided into two groups: the type 1 basalts group are tholeiites with flat REE patterns and are similar to Tocantins Province back-arc basin basalts; the type 2 basalts group have high Nb contents and are comparable to Nb- Archean-Paleoproterozoic Terrane of Goiás Faina greenstone belt enriched basalts. -
Petrology and Geochemistry of Boninite Series Volcanic Rocks, Chichi-Jima, Bonin Islands, Japan
PETROLOGY AND GEOCHEMISTRY OF BONINITE SERIES VOLCANIC ROCKS, CHICHI-JIMA, BONIN ISLANDS, JAPAN P.F. Dobson Earth Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 S. Maruyama Department of Earth and Planetary Sciences, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8551, Japan J.G. Blank Center for the Study of Life in the Universe, SETI Institute, 515 N. Whisman Road, Mountain View, California 94043 J.G. Liou Department of Geological and Environmental Sciences, Stanford University, Stanford, California 94305 Abstract An Eocene submarine boninite series volcanic center is exposed on the island of Chichi-jima, Bonin Islands, Japan. Five rock types, boninite, bronzite andesite, dacite, quartz dacite, and rhyolite, were distinguished within the boninite volcanic sequence on the basis of petrographic and geochemical observations. Boninite lavas contain high magnesium, nickel, and chromium contents indicative of primitive melts, but have high silica contents relative to other mantle- derived magmas. All boninite series lavas contain very low incompatible element concentrations, and concentrations of high-field strength elements in primitive boninite lavas are less than half of those found in depleted mid-ocean ridge basalts. Abundances of large-ion lithophile elements are relatively high in boninite series lavas, similar to the enrichments observed in many island arc lavas. Trends for both major and trace element data suggest that the more evolved lavas of the boninite magma series were derived primarily through high-level fractional crystallization of boninite. Textural features, such as resorption and glomeroporphyrocrysts, and reverse chemical zonations suggest that magma mixing contributed to the development of the quartz dacite lavas. Introduction A well exposed sequence of Eocene boninite series volcanic rocks are found on Chichi-jima (Figure 1), the type locality for boninites (Peterson, 1891). -
Magmatic Evolution of Early Subduction Zones: Geochemical Modeling and Chemical Stratigraphy of Boninite and Fore Arc Basalt from the Bonin Fore Arc
Utah State University DigitalCommons@USU All Graduate Theses and Dissertations Graduate Studies 5-2017 Magmatic Evolution of Early Subduction Zones: Geochemical Modeling and Chemical Stratigraphy of Boninite and Fore Arc Basalt from the Bonin Fore Arc Emily A. Haugen Utah State University Follow this and additional works at: https://digitalcommons.usu.edu/etd Part of the Geology Commons Recommended Citation Haugen, Emily A., "Magmatic Evolution of Early Subduction Zones: Geochemical Modeling and Chemical Stratigraphy of Boninite and Fore Arc Basalt from the Bonin Fore Arc" (2017). All Graduate Theses and Dissertations. 5934. https://digitalcommons.usu.edu/etd/5934 This Thesis is brought to you for free and open access by the Graduate Studies at DigitalCommons@USU. It has been accepted for inclusion in All Graduate Theses and Dissertations by an authorized administrator of DigitalCommons@USU. For more information, please contact [email protected]. MAGMATIC EVOLUTION OF EARLY SUBDUCTION ZONES: GEOCHEMICAL MODELING AND CHEMICAL STRATIGRAPHY OF BONINITE AND FORE ARC BASALT FROM THE BONIN FORE ARC by Emily A. Haugen A thesis submitted in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE in Geology Approved: ________________________ ________________________ John Shervais, Ph.D. Alexis Ault, Ph.D. Major Professor Committee Member ________________________ ________________________ Anthony Lowry, Ph.D. Mark R. McLellan, Ph.D. Committee Member Vice President for Research and Dean of the School of Graduate Studies UTAH STATE UNIVERSITY Logan, Utah 2017 ii Copyright Emily A. Haugen 2017 All Rights Reserved iii ABSTRACT Magmatic Evolution of Early Subduction Zones: Geochemical Modeling and Chemical Stratigraphy of Boninite and Fore Arc Basalt from the Bonin Fore Arc by Emily A. -
Geodynamic Evolution of a Forearc Rift in the Southernmost Mariana Arc Julia M
University of Rhode Island DigitalCommons@URI Graduate School of Oceanography Faculty Graduate School of Oceanography Publications 2013 Geodynamic Evolution of a Forearc Rift in the Southernmost Mariana Arc Julia M. Ribeiro Robert J. Stern See next page for additional authors Follow this and additional works at: https://digitalcommons.uri.edu/gsofacpubs The University of Rhode Island Faculty have made this article openly available. Please let us know how Open Access to this research benefits oy u. This is a pre-publication author manuscript of the final, published article. Terms of Use This article is made available under the terms and conditions applicable towards Open Access Policy Articles, as set forth in our Terms of Use. Citation/Publisher Attribution Ribeiro, Julia M., et al. "Geodynamic Evolution of a Forearc Rift in the outheS rnmost Mariana Arc." Island Arc 22.4 (2013): 453-476. Available at: http://dx.doi.org/10.1111/iar.12039 This Article is brought to you for free and open access by the Graduate School of Oceanography at DigitalCommons@URI. It has been accepted for inclusion in Graduate School of Oceanography Faculty Publications by an authorized administrator of DigitalCommons@URI. For more information, please contact [email protected]. Authors Julia M. Ribeiro, Robert J. Stern, Fernando Martinez, Osamu Ishizuka, Susan G. Merle, Katherine Kelley, Elizabeth Y. Anthony, Minghua Ren, Yasuhiko Ohara, Mark Reagan, Guillaume Girard, and Sherman Bloomer This article is available at DigitalCommons@URI: https://digitalcommons.uri.edu/gsofacpubs/37 1 Geodynamic evolution of a forearc rift in the southernmost Mariana Arc 2 3 Julia M. -
Geodynamic Setting of Izu-Bonin-Mariana Boninites
Geodynamic setting of Izu-Bonin-Mariana boninites ANNE DESCHAMPS 1 & SERGE LALLEMAND 2 Uapan Marine Science and Technology Centre (JAMSTEC), Deep Sea Research Department, 2-15 Natsushima-cho, Yokosuka 237-0061, Japan (e-mail: deschamps@jamstec, g o.jp ) 2Universite Montpellier 2, Lab. Geophysique, Tectonique & Sedimentologie, cc 060, Place E. Bataillon, 34095 Montpellier cedex 5, FRANCE Abstract: The Izu-Bonin-Mariana (IBM) forearc is characterized by the occurrence of boninite-like lavas. The study of the Cenozoic setting of the genesis of these boninitic lavas in light of modern geodynamic contexts in the Tonga and Fiji regions lead us to define three tectonic settings that favour the formation of boninites in back-arc basins in addition to previous settings that involve the presence of a mantle plume: (1) propagation at low angle between a spreading centre and the associated volcanic arc; (2) intersection at a high angle of an active spreading centre and a transform fault at the termination of an active volcanic arc; and (3) intersection at a right angle between an active spreading centre and a newly created subduction zone. A geodynamic model of the Philippine Sea Plate shows that boninites in the Bonin Islands are related to the second mechanism mentioned above, whereas Mariana forearc boninites are relevant to the third mechanism. In the early Eocene, the transform plate boundary, bounding the eastern margin of the Philippine Sea Plate at the location of the present-day Mariana arc evolved into a subduction zone that trends perpendicular to the active spreading centre of the West Philippine Basin, some- where around 43-47 Ma. -
1 Revision #2 2 PETROLOGIC EVOLUTION of BONINITE LAVAS
This is the peer-reviewed, final accepted version for American Mineralogist, published by the Mineralogical Society of America. The published version is subject to change. Cite as Authors (Year) Title. American Mineralogist, in press. DOI: https://doi.org/10.2138/am-2021-7733. http://www.minsocam.org/ 1 1 2 Revision #2 3 PETROLOGIC EVOLUTION OF BONINITE LAVAS FROM THE IBM FORE-ARC, 4 IODP EXPEDITION 352: EVIDENCE FOR OPEN-SYSTEM PROCESSES DURING 5 EARLY SUBDUCTION ZONE MAGMATISM 6 Jesse L. Scholppa, Jeffrey G. Ryana, John W. Shervaisb, Ciprian Stremtanc, Martin Rittnerd, 7 Antonio Lunaa, Stephen A. Hilla, Zachary D. Atlasa, Bradford C. Macka 8 a School of Geosciences, University of South Florida, 4202 E. Fowler Avenue, NES 107, Tampa, 9 FL, 33620 USA 10 b Department of Geology, Utah State University, 4505 Old Main Hill, Logan, UT, 84322 USA 11 c Teledyne CETAC Technologies, 14306 Industrial Road, Omaha, NE, 68144 USA 12 d TOFWERK AG, Schorenstrasse 39, 3645 Thun, Switzerland 13 ABSTRACT 14 Boninite samples from several intervals within Hole U1439C, recovered during IODP 15 Expedition 352, show highly variable mineral chemistries that imply complex crystallization 16 histories. Small pyroxene grains show oscillatory zoning with cores and zones ranging from 17 pigeonite to augite. Late crystallizing augite has highly variable Al2O3 contents (1.9-13.7 wt%.) 18 and Ca-Tschermak component contents (3-13 mol%), which reflect disequilibrium conditions. 19 Large, euhedral, low-Ca pyroxene (i.e., enstatite/clinoenstatite) crystals exhibit complex sector 20 and oscillatory zoning patterns. Cr-rich spinel is found as inclusions both in olivine and low-Ca 21 pyroxene.