DOCSLIB.ORG

Accretionary Mesozoic–Cenozoic Expansion of the Cordilleran Continental Margin in California and Adjacent Oregon

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Accretionary Mesozoic–Cenozoic Expansion of the Cordilleran Continental Margin in California and Adjacent Oregon Accretionary Mesozoic–Cenozoic expansion of the Cordilleran continental margin in California and adjacent Oregon William R. Dickinson Department of Geosciences, University of Arizona, Tucson, Arizona 85721, USA ABSTRACT Franciscan subduction was largely coeval motion of the Pacifi c plate along the evolving with intrusion of the dominantly Cretaceous San Andreas transform. My method is to pre sent The Mesozoic–Cenozoic Cordilleran oro- Sierra Nevada batholith into the roots of the summary geologic maps showing the accretion- gen of California includes multiple accre- Cordilleran magmatic arc, but Franciscan ary belts in plan view and accompanying chro- tionary belts incorporated sequentially into accretion was just a late phase of continuing nostratigraphic diagrams that display transverse the continental margin since Middle Trias- tectonic expansion that spanned more than age relationships of rocks both within the accre- sic time. Accreted tectonic elements include 200 m.y. along the California continental tionary belts and superimposed upon them. The subduction complexes assembled along the margin. coordinated maps and diagrams spanning the Cordilleran margin, intraoceanic island full width of California Mesozoic–Cenozoic arcs attached to the continental margin by Keywords: accretion, California, Klamath accretionary tracts were compiled from mul- Jurassic arc-continent collision, and subduc- Mountains, Sierra Nevada, tectonics. tiple sources cited in fi gure captions, and have tion complexes associated with the fl anks of no counterparts of equivalent scope in the litera- the exotic island arcs. Systematic analysis INTRODUCTION ture. The ages of the rock assemblages within of areal relations and geochronological data the accretionary belts, and of the stitching plu- displayed on subregional geologic maps and Ever since the seminal papers of Hamilton tons and sedimentary cover sequences that tie summary chronostratigraphic diagrams (1969) on “underfl ow” (subduction) of Pacifi c the belts together, set constraints on the times allows the punctuated but quasi-continuous mantle beneath California, and of Moores (1970) of amalgamation of the successive belts into the pattern of tectonic accretion to be discerned. on the accretion of intraoceanic arc structures to edge of the continent. Systematic interpretations Stitching plutons and sedimentary overlap the continental margin, geoscientists have been of the maps and diagrams also call attention to successions constrain the times that succes- trying to comprehend the scope and geometry of shortcomings in the currently available database, sive accretionary belts were juxtaposed and tectonic accretion at ancient subduction zones in and thereby indicate the kinds of information amalgamated into the edge of the continental California (e.g., Ernst, 1983, 1984). This paper needed to resolve uncertainties in the tectonic block. In the Klamath Mountains and Sierra is an appraisal of the Mesozoic–Cenozoic accre- history of the region. Nevada, a continental-margin magmatic arc tionary expansion of the California continental The northwest-trending Mesozoic–Cenozoic of Triassic–Jurassic age includes volcanic and margin based on a fresh synthesis of incremen- lithotectonic belts of California are separated plutonic components built upon and intruded tal geologic mapping and geochronological from the interior of the Laurentian craton by the into deformed Paleozoic assemblages that studies by many geoscientists during the past deformed Cordilleran miogeocline overthrust were accreted to the Laurentian margin several decades. Traverses along key transects by Paleozoic terranes accreted before Middle before Middle Triassic time. The native arc across all the accretionary belts during the inter- Triassic time and discussed in detail elsewhere assemblage is separated from intraoceanic val 1998–2004 gave me personal impressions of (Dickinson, 2000, 2006). Westward toward the Triassic–Jurassic arc assemblages exposed each as a context for understanding descriptions coast, multiple subparallel tectonic assemblages farther west by a compound suture belt of by others in the literature. This overview does of diverse origin were thereafter added to the mélange and broken formation derived from not extend southward into the California Trans- fl ank of Laurentia during Mesozoic–Cenozoic the remnant ocean basin that separated the verse Ranges, where onshore transrotation and subduction (Fig. 1): (1) a native Mesozoic arc east-facing intraoceanic arc system from the offshore rifting have transposed and disrupted succession built on pre-Mesozoic rocks of the Cordilleran margin. Polarity reversal after key tectonic elements, but does extend north- evolving continental margin; (2) a suture zone Middle to Late Jurassic arc-continent colli- ward to include the Oregon extension of the of tectonic mélange and broken formation sion was followed by accretion of a disrupted Klamath Mountains. immediately seaward; (3) accreted Mesozoic arc ophiolitic belt forming mafi c basement in My aim is to outline the pattern of punctu- structures seaward from the mélange belts; and the subsurface of the Great Valley forearc ated but quasi-continuous accretion of diverse (4) both Mesozoic and Cenozoic components of basin. Subsequent forearc sedimentation oceanic elements to the California continen- the Franciscan subduction complex farther west accompanied the assembly of multiple belts tal margin from mid-Triassic to mid-Tertiary near the coast. of mélange and broken formation that form time. Subsequently, tectonic accretion ended as Following introductory passages addressing the Mesozoic–Cenozoic Franciscan subduc- subduction of the Farallon and derivative oce- key topical issues, my areal treatment begins tion complex of the California Coast Ranges. anic plates was gradually supplanted by lateral with a discussion of the Klamath Mountains Geosphere; April 2008; v. 4; no. 2; p. 329–353; doi: 10.1130/GES00105.1; 9 fi gures. For permission to copy, contact [email protected] 329 © 2008 Geological Society of America Downloaded from http://pubs.geoscienceworld.org/gsa/geosphere/article-pdf/4/2/329/3336520/i1553-040X-4-2-329.pdf by guest on 29 September 2021 Dickinson 115° 120° WA ID e n W o A 45° Z OR B LUE MTNS. marginal C offset n o i t E 45° c M u IDb d N ID T b u S O Z s O e d I C E R sca C O V a C OR OR ID CA NV ID NV MTJ NV UT t s u r h st t e ru th lin s e 40° n i n a i G t l n c r u e a o 40° o backarc d e a n M basin g t lco o e o i g n V G s m rt hi a e ll b o SB n N e R a a f y r e l h l tc i a f d s o r h r SNb rc e Wa a ar Co UT N AZ l c V ta SB C n A e p R b in a if a t l NV n e S s o o H i c s f AZ s u S n n b A a d f 35° u c ti ictr o N f o 35° n a z f Ga o le a P z B o rotated isb n ee e Transverse PRb SI ri Ranges f ft ba sin 0 100 200 US M A EXI scale in km CO 120° 115° ABCDEFG T-Fran K-Fran is arcs sut belt acc Pz nat arc batho Figure 1. Position of California continental margin (west of Great Valley forearc basin) in tectonic framework of southwest Laurentia (adapted after Reed et al., 2005). Regional tectonic relations after Dickinson (2000, 2004, 2006), Dickinson et al. (2005), and this paper, with Jurassic–Cretaceous Bisbee rift basin after Dickinson and Lawton (2001b) and Triassic–Jurassic backarc basin in Nevada adapted after Wyld (2002). Barbed lines are principal thrusts (solid barbs where active). Heavy lines are strike-slip faults (Gaf—Garlock; Naf— Nacimiento; Rif—Rinconada; SAf—San Andreas; SHf—San Gregorio–Hosgri; SIf—San Isidro) with associated Mendocino triple junction (MTJ) and Salinian block (SB). Symbols: A (T-Fran)—Tertiary–uppermost Cretaceous Franciscan subduction complex and Paleogene Siletz-Umpqua assemblage; B (K-Fran)—Cretaceous–latest Jurassic Franciscan subduction complex; C (is arcs)—accreted intraoceanic Triassic–Jurassic island arcs; D (sut belt)—mid-Mesozoic suture belt (pre-Franciscan mélanges); E (acc Pz)—accreted Paleozoic crustal elements (oceanic allochthons and island arcs); F (nat arc)—native Triassic–Jurassic continental-margin arc assemblage (not shown to southeast where crosses miogeocline and southwestern prong of craton); G (batho)—major batholiths of largely Cretaceous age (IDb— Idaho; PRb—Peninsular Ranges; SNb—Sierra Nevada). 330 Geosphere, April 2008 Downloaded from http://pubs.geoscienceworld.org/gsa/geosphere/article-pdf/4/2/329/3336520/i1553-040X-4-2-329.pdf by guest on 29 September 2021 Accretionary expansion of California and adjacent California-Oregon coastal ranges Golconda thrust of Nevada, to the subduction transport estimated from paleofaunal interpre- where the various accretionary belts are most zone associated with a Permian–Triassic (284– tations as thousands of kilometers of longitude completely exposed, and then proceeds south- 232 Ma) magmatic arc in eastern Mexico to was required to bring the Tethyan limestones to ward along the Sierra Nevada and the Califor- the southeast (Dickinson and Lawton, 2001a). the Cordilleran continental margin (Stevens et nia Coast Range. Original relationships of the Major strike slip postdated terminal juxtaposi- al., 1990, 1991; Belasky and Stevens, 2006). accretionary belts are progressively obscured tion of Gondwana against Laurentia along the southward by intrusion of the Mesozoic Sierra diachronous Ouachita-Marathon suture belt that Lateral Translation Nevada batholith, deposition of overlying Meso- closed in earliest Permian time in west Texas zoic or Cenozoic sedimentary cover, and post- (Ross, 1986). Interpretations of the California segment of accretion deformation including disruption by The line of truncation was oriented northwest- the Cordilleran orogen developed for the Geo- multiple strands of the Neogene San Andreas southeast at a high angle to the northeast-south- logical Society of America Decade of North transform fault system near the coast.
Load more

Recommended publications
  • Geologic Gems of California's State Parks
    STATE OF CALIFORNIA – EDMUND G. BROWN JR., GOVERNOR NATURAL RESOURCES AGENCY – JOHN LAIRD, SECRETARY CALIFORNIA GEOLOGICAL SURVEY DEPARTMENT OF PARKS AND RECREATION – LISA MANGAT, DIRECTOR JOHN D. PARRISH, Ph.D., STATE GEOLOGIST DEPARTMENT OF CONSERVATION – DAVID BUNN, DIRECTOR PLATE 1 The rugged cliffs of Del Norte Coast Redwoods State Park are composed of some of California’s Bio-regions the most tortured, twisted, and mobile rocks of the North American continent. The California’s Geomorphic Provinces rocks are mostly buried beneath soils and covered by vigorous redwood forests, which thrive in a climate famous for summer fog and powerful winter storms. The rocks only reveal themselves in steep stream banks, along road and trail cut banks, along the precipitous coastal cliffs and offshore in the form of towering rock monuments or sea stacks. (Photograph by CalTrans staff.) Few of California’s State parks display impressive monoliths adorned like a Patrick’s Point State Park displays a snapshot of geologic processes that have castle with towering spires and few permit rock climbing. Castle Crags State shaped the face of western North America, and that continue today. The rocks Park is an exception. The scenic beauty is best enjoyed from a distant exposed in the seacliffs and offshore represent dynamic interplay between the vantage point where one can see the range of surrounding landforms. The The Klamath Mountains consist of several rugged ranges and deep canyons. Klamath/North Coast Bioregion San Joaquin Valley Colorado Desert subducting oceanic tectonic plate (Gorda Plate) and the continental North American monolith and its surroundings are a microcosm of the Klamath Mountains The mountains reach elevations of 6,000 to 8,000 feet.
    [Show full text]
  • Multi-Stage Origin of the Coast Range Ophiolite, California: Implications for the Life Cycle of Supra-Subduction Zone Ophiolites
    International Geology Review, Vol. 46, 2004, p. 289–315. Copyright © 2004 by V. H. Winston & Son, Inc. All rights reserved. Multi-Stage Origin of the Coast Range Ophiolite, California: Implications for the Life Cycle of Supra-Subduction Zone Ophiolites JOHN W. S HERVAIS,1 Department of Geology, Utah State University, 4505 Old Main Hill, Logan, Utah 84322-4505 DAVID L. KIMBROUGH, Department of Geological Sciences, San Diego State University, San Diego California 92182-1020 PAUL RENNE, Berkeley Geochronology Center, 2455 Ridge Road, Berkeley, California 94709 and Department of Earth and Planetary Science, University of California, Berkeley, California 94720 BARRY B. HANAN, Department of Geological Sciences, San Diego State University, San Diego California 92182-1020 BENITA MURCHEY, United States Geological Survey, 345 Middlefield Road, Menlo Park California 94025 CAMERON A. SNOW, Department of Geology, Utah State University, 4505 Old Main Hill, Logan, Utah 84322-4505 and Department of Geological and Environmental Sciences, Stanford University, Stanford, California 94305 MARCHELL M. ZOGLMAN SCHUMAN,2 AND JOE BEAMAN3 Department of Geological Sciences, University of South Carolina, Columbia, South Carolina 29208 Abstract The Coast Range ophiolite of California is one of the most extensive ophiolite terranes in North America, extending over 700 km from the northernmost Sacramento Valley to the southern Trans- verse Ranges in central California. This ophiolite, and other ophiolite remnants with similar mid- Jurassic ages, represent a major but short-lived episode of oceanic crust formation that affected much of western North America. The history of this ophiolite is important for models of the tectonic evolution of western North America during the Mesozoic, and a range of conflicting interpretations have arisen.
    [Show full text]
  • Geologic History of Siletzia, a Large Igneous Province in the Oregon And
    Geologic history of Siletzia, a large igneous province in the Oregon and Washington Coast Range: Correlation to the geomagnetic polarity time scale and implications for a long-lived Yellowstone hotspot Wells, R., Bukry, D., Friedman, R., Pyle, D., Duncan, R., Haeussler, P., & Wooden, J. (2014). Geologic history of Siletzia, a large igneous province in the Oregon and Washington Coast Range: Correlation to the geomagnetic polarity time scale and implications for a long-lived Yellowstone hotspot. Geosphere, 10 (4), 692-719. doi:10.1130/GES01018.1 10.1130/GES01018.1 Geological Society of America Version of Record http://cdss.library.oregonstate.edu/sa-termsofuse Downloaded from geosphere.gsapubs.org on September 10, 2014 Geologic history of Siletzia, a large igneous province in the Oregon and Washington Coast Range: Correlation to the geomagnetic polarity time scale and implications for a long-lived Yellowstone hotspot Ray Wells1, David Bukry1, Richard Friedman2, Doug Pyle3, Robert Duncan4, Peter Haeussler5, and Joe Wooden6 1U.S. Geological Survey, 345 Middlefi eld Road, Menlo Park, California 94025-3561, USA 2Pacifi c Centre for Isotopic and Geochemical Research, Department of Earth, Ocean and Atmospheric Sciences, 6339 Stores Road, University of British Columbia, Vancouver, BC V6T 1Z4, Canada 3Department of Geology and Geophysics, University of Hawaii at Manoa, 1680 East West Road, Honolulu, Hawaii 96822, USA 4College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, 104 CEOAS Administration Building, Corvallis, Oregon 97331-5503, USA 5U.S. Geological Survey, 4210 University Drive, Anchorage, Alaska 99508-4626, USA 6School of Earth Sciences, Stanford University, 397 Panama Mall Mitchell Building 101, Stanford, California 94305-2210, USA ABSTRACT frames, the Yellowstone hotspot (YHS) is on southern Vancouver Island (Canada) to Rose- or near an inferred northeast-striking Kula- burg, Oregon (Fig.
    [Show full text]
  • Timing and Structural Expression of the Nevadan Orogeny, Sierra Nevada, California: Discussions and Reply
    Timing and structural expression of the Nevadan orogeny, Sierra Nevada, California: Discussions and reply Discussion TAPAS BHATTACHARYYA i _ „ . _ . ,, . , _ ... „ , _ _ ,., . nATi-DCAM I ^art'1 Science Board, University of California, Santa Cruz, California 95064 SCO IT R. PA [ bKSON / Prior to commenting on several aspects of the paper by Schweickert and others, 1984, can be divided into four topics: (1) the position/exist- and others, 1984, we wish to note that we have benefited from the work of ence of the "Sonora fault," (2) the "polymetamorphism and structural these authors. We also wish to note that all of our comments concern complexity" of the Calaveras Complex and Shoo Fly Formation, (3) the statements made about the southern portion of the Western Metamorphic interpretation of "Late Phase" or Cretaceous folds and possible conjugate Belt where we are presently completing an east-west transect on scales of structures, and (4) their model for "rigid body rotation of the central belt" 1:24,000 and larger. during Nevadan deformation. We will discuss each of these in turn. Our objections to observations and interpretations by Schweickert 1. Many of the age relations and positions of contacts/faults dis- cussed by Schweickert and others, 1984, are better established in the The article discussed appeared in the Bulletin, v. 95, p. 967-979. northern Sierra or the part of the southern belt which lies north of 3£ We Geological Society of America Bulletin, v. 96, p. 1346-1352, 1 fig., October 1985. Downloaded from http://pubs.geoscienceworld.org/gsa/gsabulletin/article-pdf/96/10/1349/3445091/i0016-7606-96-10-1349.pdf by guest on 02 October 2021 DISCUSSIONS AND REPLY 1347 think that similar relations are not nearly so well established in the south- Belt.
    [Show full text]
  • Major Chemical Characteristics of Mesozoic Coast Range Ophiolite in California
    JOURNAL OF OF THE U.S. GEOLOGICAL SURVEY NOVEMBER-DECEMBER 1974 VOLUME 2, NUMBER 6 Scientific notes and summaries of investigations in geology, hydrology, and related fields +r U«/ fc/ U.S. DEPARTMENT OF THE INTERIOR UNITED STATES DEPARTMENT OF THE INTERIOR ROGERS C. B. MORTON, Secretary GEOLOGICAL SURVEY V. E. McKelvey, Director For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, DC The Journal of Research is pub­ Correspondence and inquiries concerning the Jour­ 20402. Order by SD Catalog No. lished every 2 months by the U.S. nal (other than subscription inquiries and address JRGS. Annual subscription rate Geological Survey. It contains changes) should be directed to the Journal of Re­ $15.50 (plus $3.75 for foreign mail­ papers by members of the Geologi­ search, Publications Division, U.S. Geological Survey, ing). Single copy $2.75. Make cal Survey and their professional National Center 321, Reston, VA 22092. checks or money orders payable to colleagues on geologic, hydrologic, the Superintendent of Documents. topographic, and other scientific Papers for the Journal should be submitted through Send all subscription inquiries and technical subjects. regular Division publication channels. and address changes to the Superin­ tendent of Documents at the above address. Purchase orders should not be sent to the U.S. Geological Survey The Secretary of the Interior has determined that the publication of this periodical is library. necessary in the transaction of the public business required by law of this Department. Library of Congress Catalog-card Use of funds for printing this periodical has been approved by the Director of the Office No.
    [Show full text]
  • The Saharides and Continental Growth During the Final Assembly of Gondwana-Land
    Reconstructing orogens without biostratigraphy: The Saharides and continental growth during the final assembly of Gondwana-Land A. M. Celâl S¸ engöra,b,1, Nalan Lomc, Cengiz Zabcıb, Gürsel Sunalb, and Tayfun Önerd aIstanbul_ Teknik Üniversitesi (ITÜ)_ Avrasya Yerbilimleri Enstitüsü, Ayazaga˘ 34469 Istanbul,_ Turkey; bITÜ_ Maden Fakültesi, Jeoloji Bölümü, Ayazaga˘ 34469 Istanbul,_ Turkey; cDepartement Aardwetenschappen, Universiteit Utrecht, 3584 CB Utrecht, The Netherlands; and dSoyak Göztepe Sitesi, Üsküdar 34700 Istanbul,_ Turkey Contributed by A. M. Celâl S¸ engör, October 3, 2020 (sent for review July 17, 2020; reviewed by Jonas Kley and Leigh H. Royden) A hitherto unknown Neoproterozoic orogenic system, the Sahar- identical to those now operating (the snowball earth and the ab- ides, is described in North Africa. It formed during the 900–500-Ma sence of land flora were the main deviating factors), yet the interval. The Saharides involved large subduction accretion com- dominantly biostratigraphy-based methods used to untangle oro- plexes occupying almost the entire Arabian Shield and much of genic evolution during the Phanerozoic are not applicable Egypt and parts of the small Precambrian inliers in the Sahara in- to them. cluding the Ahaggar mountains. These complexes consist of, at least by half, juvenile material forming some 5 million km2 new Method of Reconstructing Complex Orogenic Evolution in continental crust. Contrary to conventional wisdom in the areas the Neoproterozoic without Biostratigraphy: Example of the they occupy,
    [Show full text]
  • 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.
    [Show full text]
  • Oceanic Plateau and Island Arcs of Southwestern Ecuador: Their Place in the Geodynamic Evolution of Northwestern South America
    Reprinted from TECTONOPHYSICS INTERNATIONAL JOURNAL OF GEOTECTONICS AND THE GEOLOGY AND PHYSICS OF THE INTERIOR OF THE EARTH Tectonophysics 307 (1999) 235-254 Oceanic plateau and island arcs of southwestern Ecuador: their place in the geodynamic evolution of northwestern South America Cédric Reynaud a, fitienne Jaillard a,b, Henriette Lapierre al*, Marc Mamberti %c, Georges H. Mascle a '' UFRES, A-5025, Université Joseph Fourier; Institut Doloniieu, 15 rue Maurice-Gignoux, 38031 Grenoble cedex, Francel IO, "IRD lfoniierly ORSTOM), CSI, 209-213 rue Lu Fayette, 75480 Faris cedex France 'Institut de Minéralogie et Fétrogrphie, Université de Lausanne, BFSH2 (3171), I015 Lausanne, Switzerland Received 12 August 1997; accepted 11 March 1999 Fonds Documentaire ORSTOM 9" ELSEVIER Cote :&e4 973 9 Ex : LII>f c.- TECTONOPHYSICS Editors-in-Chief J.-P. BURG ETH-Zentrum, Geologisches Institut, Sonneggstmße 5, CH-8092, Zürich, Switzerland. Phone: +41.1.632 6027; FAX: +41.1.632 1080; e-mail: [email protected] T. ENGELDER Pennsylvania State University, College of Earth & Mineral Sciences, 336 beike Building, University Park, PA 16802, USA. Phone: +I .814.865.3620/466.7208; FAX: +I .814.863.7823; e-mail: engelderOgeosc.psu.edu K.P. FURLONG Pennsylvania State University, Department of Geosciences, 439 Deike Building, University Park, PA 16802, USA. Phone: +1 .814.863.0567; FAX: +1.814.865.3191; e-mail: kevinOgeodyn.psu.edu F. WENZEL Universität Fridericiana Karlsruhe, Geophysikalisches Institut, Hertzstraße Bau Karlsruhe, Germany. .physik.uni-karlsruhe.de16, 42, D-76187 Phone: +49.721.608 4431; FAX +49.721.711173; e-mail: fwenzel@gpiwapl Honorary Editor: S. Uyeda Editorial Board Z.
    [Show full text]
  • Future Accreted Terranes: a Compilation of Island Arcs, Oceanic Plateaus, Submarine Ridges, Seamounts, and Continental Fragments” by J
    Open Access Solid Earth Discuss., 6, C1212–C1222, 2014 www.solid-earth-discuss.net/6/C1212/2014/ Solid Earth © Author(s) 2014. This work is distributed under Discussions the Creative Commons Attribute 3.0 License. Interactive comment on “Future accreted terranes: a compilation of island arcs, oceanic plateaus, submarine ridges, seamounts, and continental fragments” by J. L. Tetreault and S. J. H. Buiter J. L. Tetreault and S. J. H. Buiter [email protected] Received and published: 30 October 2014 Response to Review C472: M. Pubellier I thank M. Pubellier for his in-depth review; the suggestions are very constructive and have truly improved the manuscript. I will first reply to the review letter below, and then to points in the supplement that need further explanation/discussion. Otherwise, if the point is not addressed, it has simply been corrected. In the review letter, the reviewer writes: I agree with most of the results presented in this paper but I regret a bit that the empha- C1212 sis was a bit too much on ancient examples (except the Solomon Islands and Taiwan that has been just mentioned). The authors could give more attention to the recent examples such as Southeast Asia. I have suggested some examples (which of course are those I know well) for reference; but there are others. I am sorry to have put some references of papers for which I participated but it is just for the sake of discussion. I think some examples of recent tectonics bring elements in this interesting discussion. The reviewer comments that my paper is quite heavy on ancient examples of accreted terranes, and I admit, now looking back on my review, that it was done so, albeit sub- consciously.
    [Show full text]
  • Review of Cordilleran Tectonics
    The Wacky Wonderful World of Cordilleran Tectonics Event Timing Description Transform Tectonics Middle Miocene - As North American Plate overran the divergent boundary of the Farallon and Pacific plates, change in sense of along California Coast Holocene motion from subduction to transform; birth of San Andreas Fault system; sealing off of southern entrance to Great Valley of California as sliver of crust containing Baja California and Los Angeles moves northward Half-graben Rise of Late Pliocene Large scale tilting of old plutons (emplaced in Nevadan orogeny) in eastern California, producing modern Sierra Sierra Nevada Nevada Basin-and-Range Miocene – Pliocene Large-scale extension in American Southwest, thinning continental crust and widening region by 50-100%; Extension & Volcanism associated regional volcanism Coastal Range Orogeny Late Miocene – Subduction along western coastline producing Andean-style volcanoes (Coastal Ranges of California, Cascades of Holocene Northwest); continues to operate in Northwest Flood Basalts in Miocene – Pliocene Columbia River Basalts (Miocene); Snake River Extrusives (Pliocene) Northwest Uplift of Colorado Middle Miocene Large vertical uplift of flat region in American Southwest, with little internal disturbance; downward erosion of Plateau Colorado River produces Grand Canyon Exhumation of the Early Miocene – Uplift of ~1600 m; erosion of much of the alluvium formed in the Oligocene; downward cutting action of rivers Rockies Pliocene produces “meandering” streams inside mountains Erosion of Cordillera Oligocene Erosion of Laramide uplift produces alluvium which largely fills up the intramontane basins and which spreads in large wedges into the cratonic interior; meandering rivers eventually form on these wedges. The tops of the mountains are weathered down to form broad flat surfaces confluent with the alluvial wedges.
    [Show full text]
  • Plate Boundary Evolution in the Halmahera Region, Indonesia
    ~ectono~h~s~c~, 144 (1987) 337-352 337 EIsevier Science Publishers B.Y., Amsterd~ - Printed in The Netberiands Plate boundary evolution in the Halmahera region, Indonesia ROBERT HALL (Received December 1.1986; revised version accepted March 10,1987) Abstract Hall, R., 1987. Plate boundaryevolution in the Halmahera region, Indonesia. ~e~~~no~~.y~jcs,144: 337-352, H&mahera is situated in eastern Indonesia at the southwest comer of the Philippine Sea PIate. Active arc-arc collision is in process in the Molucca Sea to the west of Halmahera. New stratigraphic observations from Halmahera link this island and the east P~Iippin~ and record the history of subduction of the Molucca Sea lithosphere. The HaImahera Basement Complex and the basement of east Mindanao were part of an arc and forearc of Late Cretaceous-Early Tertiary age and have formed part of a single plate since the Late Eocene-Early Oligocene. There is no evidence that HaImabera formed part of an Oligo-Miocene arc but arc volcanism, associated with eastwards subduction of the Molucca Sea beneath Halmahera, began in the Pliocene and the Pliocene arc is built on a basement of the early Tertiary arc. Arc volcanism ceased briefIy during the Pleistocene and the arc shifted westwards after an episode of deformation. The present active arc is built upon deformed rocks of the Ptiocene arc. The combination of new strati~ap~c info~ation from the genera islands and models of the present-day tectonic structure of the region deduced from seismic and other geophysicat studies is used to constrain the tectonic evolution of the region since the Miocene.
    [Show full text]
  • Geological–Tectonic Framework of Solomon Islands, SW Pacific
    ELSEVIER Tectonophysics 301 (1999) 35±60 Geological±tectonic framework of Solomon Islands, SW Paci®c: crustal accretion and growth within an intra-oceanic setting M.G. Petterson a,Ł, T. Babbs b, C.R. Neal c, J.J. Mahoney d, A.D. Saunders b, R.A. Duncan e, D. Tolia a,R.Magua, C. Qopoto a,H.Mahoaa, D. Natogga a a Ministry of Energy Water and Mineral Resources, Water and Mineral Resources Division, P.O. Box G37, Honiara, Solomon Islands b Department of Geology, University of Leicester, University Road, Leicester LE1 7RH, UK c Department of Civil Engineering and Geological Sciences, University of Notre Dame, Notre Dame, Indiana 46556, USA d School of Ocean and Earth Science and Technology, University of Hawaii, 2525 Correa Road, Honolulu, Hawaii 96822, USA e College of Oceanographic and Atmospheric Sciences, Oregon State University, Corvallis, Oregon 97331, USA Received 10 June 1997; accepted 12 August 1998 Abstract The Solomon Islands are a complex collage of crustal units or terrains (herein termed the `Solomon block') which have formed and accreted within an intra-oceanic environment since Cretaceous times. Predominantly Cretaceous basaltic basement sequences are divided into: (1) a plume-related Ontong Java Plateau terrain (OJPT) which includes Malaita, Ulawa, and northern Santa Isabel; (2) a `normal' ocean ridge related South Solomon MORB terrain (SSMT) which includes Choiseul and Guadalcanal; and (3) a hybrid `Makira terrain' which has both MORB and plume=plateau af®nities. The OJPT formed as an integral part of the massive Ontong Java Plateau (OJP), at c. 122 Ma and 90 Ma, respectively, was subsequently affected by Eocene±Oligocene alkaline and alnoitic magmatism, and was unaffected by subsequent arc development.
    [Show full text]