Foreland Uplift During Flat Subduction Insights from the Peruvian Andes
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Uplift, Rupture, and Rollback of the Farallon Slab Reflected in Volcanic
PUBLICATIONS Journal of Geophysical Research: Solid Earth RESEARCH ARTICLE Uplift, rupture, and rollback of the Farallon slab reflected 10.1002/2017JB014517 in volcanic perturbations along the Yellowstone Key Points: adakite hot spot track • Volcanic perturbations in the Cascadia back-arc region are derived from uplift Victor E. Camp1 , Martin E. Ross2, Robert A. Duncan3, and David L. Kimbrough1 and dismemberment of the Farallon slab from ~30 to 20 Ma 1Department of Geological Sciences, San Diego State University, San Diego, California, USA, 2Department of Earth and • Slab uplift and concurrent melting 3 above the Yellowstone plume Environmental Sciences, Northeastern University, Boston, Massachusetts, USA, College of Earth, Ocean, and Atmospheric promoted high-K calc-alkaline Sciences, Oregon State University, Corvallis, Oregon, USA volcanism and adakite generation • Creation of a seismic hole beneath eastern Oregon resulted from thermal Abstract Field, geochemical, and geochronological data show that the southern segment of the ancestral erosion and slab rupture, followed by Cascades arc advanced into the Oregon back-arc region from 30 to 20 Ma. We attribute this event to thermal a period of slab rollback uplift of the Farallon slab by the Yellowstone mantle plume, with heat diffusion, decompression, and the release of volatiles promoting high-K calc-alkaline volcanism throughout the back-arc region. The greatest Supporting Information: • Supporting Information S1 degree of heating is expressed at the surface by a broad ENE-trending zone of adakites and related rocks • Data Set S1 generated by melting of oceanic crust from the Farallon slab. A hiatus in eruptive activity began at ca. • Data Set S2 22–20 Ma but ended abruptly at 16.7 Ma with renewed volcanism from slab rupture occurring in two separate • Data Set S3 regions. -
0 Master's Thesis the Department of Geosciences And
Master’s thesis The Department of Geosciences and Geography Physical Geography South American subduction zone processes: Visualizing the spatial relation of earthquakes and volcanism at the subduction zone Nelli Metiäinen May 2019 Thesis instructors: David Whipp Janne Soininen HELSINGIN YLIOPISTO MATEMAATTIS-LUONNONTIETEELLINEN TIEDEKUNTA GEOTIETEIDEN JA MAANTIETEEN LAITOS MAANTIEDE PL 64 (Gustaf Hällströmin katu 2) 00014 Helsingin yliopisto 0 Tiedekunta/Osasto – Fakultet/Sektion – Faculty Laitos – Institution – Department Faculty of Science The Department of Geosciences and Geography Tekijä – Författare – Author Nelli Metiäinen Työn nimi – Arbetets titel – Title South American subduction zone processes: Visualizing the spatial relation of earthquakes and volcanism at the subduction zone Oppiaine – Läroämne – Subject Physical Geography Työn laji – Arbetets art – Level Aika – Datum – Month and year Sivumäärä – Sidoantal – Number of pages Master’s thesis May 2019 82 + appencides Tiivistelmä – Referat – Abstract The South American subduction zone is the best example of an ocean-continent convergent plate margin. It is divided into segments that display different styles of subduction, varying from normal subduction to flat-slab subduction. This difference also effects the distribution of active volcanism. Visualizations are a fast way of transferring large amounts of information to an audience, often in an interest-provoking and easily understandable form. Sharing information as visualizations on the internet and on social media plays a significant role in the transfer of information in modern society. That is why in this study the focus is on producing visualizations of the South American subduction zone and the seismic events and volcanic activities occurring there. By examining the South American subduction zone it may be possible to get new insights about subduction zone processes. -
Initiation of Plate Tectonics in the Hadean: Eclogitization Triggered by the ABEL Bombardment
Accepted Manuscript Initiation of plate tectonics in the Hadean: Eclogitization triggered by the ABEL Bombardment S. Maruyama, M. Santosh, S. Azuma PII: S1674-9871(16)30207-9 DOI: 10.1016/j.gsf.2016.11.009 Reference: GSF 514 To appear in: Geoscience Frontiers Received Date: 9 May 2016 Revised Date: 13 November 2016 Accepted Date: 25 November 2016 Please cite this article as: Maruyama, S., Santosh, M., Azuma, S., Initiation of plate tectonics in the Hadean: Eclogitization triggered by the ABEL Bombardment, Geoscience Frontiers (2017), doi: 10.1016/ j.gsf.2016.11.009. 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 MANUSCRIPT ACCEPTED P a g e ‐|‐1111‐‐‐‐ ACCEPTED MANUSCRIPT ‐ 1‐ Initiation of plate tectonics in the Hadean: 2‐ Eclogitization triggered by the ABEL 3‐ Bombardment 4‐ 5‐ S. Maruyama a,b,*, M. Santosh c,d,e , S. Azuma a 6‐ a Earth-Life Science Institute, Tokyo Institute of Technology, 2-12-1, 7‐ Ookayama-Meguro-ku, Tokyo 152-8550, Japan 8‐ b Institute for Study of the Earth’s Interior, Okayama University, 827 Yamada, 9‐ Misasa, Tottori 682-0193, Japan 10‐ c Centre for Tectonics, Resources and Exploration, Department of Earth 11‐ Sciences, University of Adelaide, SA 5005, Australia 12‐ d School of Earth Sciences and Resources, China University of Geosciences 13‐ Beijing, 29 Xueyuan Road, Beijing 100083, China 14‐ e Faculty of Science, Kochi University, KochiMANUSCRIPT 780-8520, Japan 15‐ *Corresponding author. -
Thermal Modelling of the Laramide Orogeny: Testing the £At-Slab Subduction Hypothesis
Available online at www.sciencedirect.com R Earth and Planetary Science Letters 214 (2003) 619^632 www.elsevier.com/locate/epsl Thermal modelling of the Laramide orogeny: testing the £at-slab subduction hypothesis Joseph M. English a;Ã, Stephen T. Johnston a, Kelin Wang a;b a School of Earth and Ocean Sciences, University of Victoria, P.O. Box 3055 STN CSC, Victoria, BC, Canada V8W 3P6 b Paci¢c Geoscience Centre, Geological Survey of Canada, 9860 West Saanich Road, Sidney, BC, Canada V8L 4B2 Received 1 April 2003; received in revised form 7 July 2003; accepted 16 July 2003 Abstract The Laramide orogeny is the Late Cretaceous to Palaeocene (80^55 Ma) orogenic event that gave rise to the Rocky Mountain fold and thrust belt in Canada, the Laramide block uplifts in the USA, and the Sierra Madre Oriental fold and thrust belt in Mexico. The leading model for driving Laramide orogenesis in the USA is flat-slab subduction, whereby stress coupling of a subhorizontal oceanic slab to the upper plate transmitted stresses eastwards, producing basement-cored block uplifts and arc magmatism in the foreland. The thermal models presented here indicate that arc magma generation at significant distances inboard of the trench ( s 600 km) during flat-slab subduction is problematic; this conclusion is consistent with the coincidence of volcanic gaps and flat-slab subduction at modern convergent margins. Lawsonite eclogite xenoliths erupted through the Colorado Plateau in Oligocene time are inferred to originate from the subducted Farallon slab, and indicate that the Laramide flat-slab subduction zone was characterised by a cold thermal regime. -
Geologic Extremes of the NW Himalaya
Louisiana State University LSU Digital Commons LSU Doctoral Dissertations Graduate School 2016 Geologic Extremes of the NW Himalaya: Investigations of the Himalayan Ultra-high Pressure and Low Temperature Deformation Histories Dennis Girard Donaldson Louisiana State University and Agricultural and Mechanical College Follow this and additional works at: https://digitalcommons.lsu.edu/gradschool_dissertations Part of the Earth Sciences Commons Recommended Citation Donaldson, Dennis Girard, "Geologic Extremes of the NW Himalaya: Investigations of the Himalayan Ultra-high Pressure and Low Temperature Deformation Histories" (2016). LSU Doctoral Dissertations. 3295. https://digitalcommons.lsu.edu/gradschool_dissertations/3295 This Dissertation is brought to you for free and open access by the Graduate School at LSU Digital Commons. It has been accepted for inclusion in LSU Doctoral Dissertations by an authorized graduate school editor of LSU Digital Commons. For more information, please [email protected]. GEOLOGIC EXTREMES OF THE NW HIMALAYA: INVESTIGATIONS OF THE HIMALAYAN ULTRA-HIGH PRESSURE AND LOW TEMPERATURE DEFORMATION HISTORIES A Dissertation Submitted to the Graduate Faculty of the Louisiana State University and Agricultural and Mechanical College in partial fulfillment of the requirements for the degree of Doctor of Philosophy in The Department of Geology and Geophysics by Dennis G. Donaldson Jr. B.S., Virginia State University, 2009 August 2016 Dedicated to Jaime, Eliya, Noah, my siblings and parents. ii ACKNOWLEDGEMENTS I am very pleased that I have had a rewarding journey during this chapter of my life with the Department of Geology and Geophysical at Louisiana State University. I would not be here right now if it wasn’t for Dr. Alex Webb, Dr. -
How Does the Nazca Ridge Subduction Influence the Modern Amazonian Foreland Basin?
Downloaded from geology.gsapubs.org on November 26, 2015 How does the Nazca Ridge subduction infl uence the modern Amazonian foreland basin? N. Espurt* LMTG, Université de Toulouse, CNRS, IRD, OMP, 14 Avenue Edouard Belin, F-31400 Toulouse, France, and P. Baby* IRD, Convenio IRD-PERUPETRO, Calle Teruel 357, Mirafl ores, Lima 18, Peru S. Brusset* LMTG, Université de Toulouse, CNRS, IRD, OMP, 14 Avenue Edouard Belin, F-31400 Toulouse, France M. Roddaz* W. Hermoza* PERUPETRO, Convenio IRD-PERUPETRO, Avenida Luis Aldana 320, San Boja, Lima 41, Peru V. Regard* LMTG, Université de Toulouse, CNRS, IRD, OMP, 14 Avenue Edouard Belin, F-31400 Toulouse, France P.-O. Antoine* R. Salas-Gismondi* Museo de Historia Natural—UNMSM, Departamento de Paleontología de Vertebrados, Avenida Arenales 1256, Lima 14, Peru R. Bolaños* PERUPETRO, Convenio IRD-PERUPETRO, Avenida Luis Aldana 320, San Boja, Lima 41, Peru ABSTRACT Fitzcarrald arch is incised by these rivers, and the The subduction of an aseismic ridge has important consequences on the dynamics of the oldest outcropping sediments are Neogene in age. overriding upper plate. In the central Andes, the Nazca Ridge subduction imprint can be Recent studies of both sides of the arch (Fig. 2A) tracked on the eastern side of the Andes. The Fitzcarrald arch is the long-wavelength topog- show Late Miocene tidal deposits (Räsänen et al., raphy response of the Nazca Ridge fl at subduction, 750 km inboard of the trench. This uplift 1995; Hovikoski et al., 2005; Gingras et al., 2002; is responsible for the atypical three-dimensional shape of the Amazonian foreland basin. -
19. Analysis and Correlation of Volcanic
Jørgensen, B.B., D’Hondt, S.L., and Miller, D.J. (Eds.) Proceedings of the Ocean Drilling Program, Scientific Results Volume 201 19. ANALYSIS AND CORRELATION OF VOLCANIC ASH IN MARINE SEDIMENTS FROM THE PERU MARGIN, OCEAN DRILLING PROGRAM LEG 201: EXPLOSIVE VOLCANIC 1 CYCLES OF THE NORTH-CENTRAL ANDES D. Hart2 and D.J. Miller3 ABSTRACT Although land studies have identified major volcanic centers of his- 1Hart, D., and Miller, D.J., 2006. toric eruptions within the Central Andes, the tephrachronologic record Analysis and correlation of volcanic is disturbed by the high erosion rates in this arid region. Owing to ero- ash in marine sediments from the Peru sion, studies of volcanic cyclicity based on subaerial deposits offer an margin, Ocean Drilling Program Leg incomplete record of the frequency and episodicity of eruptions since 201: explosive volcanic cycles of the north-central Andes. In Jørgensen, the Miocene. However, volcanic material commonly occurs in marine B.B., D’Hondt, S.L., and Miller, D.J. sediment as discrete ash fall layers and/or disseminated ash accumula- (Eds.), Proc. ODP, Sci. Results, 201, 1–43 tions. A detailed investigation of cores from three sites offshore Peru [Online]. Available from World Wide drilled during Ocean Drilling Program (ODP) Leg 201 has been con- Web: <http://www-odp.tamu.edu/ ducted to determine the occurrence of volcanic ash layers and ash accu- publications/201_SR/VOLUME/ CHAPTERS/122.PDF>. [Cited YYYY- mulations within marine sediments along the Peru shelf. These sites MM-DD] were previously occupied during ODP Leg 112, which suffered from 2Department of Geology and poor and/or disturbed core recovery. -
Structure of the Collision Zone Between the Nazca Ridge and the Peruvian Convergent Margin
RESEARCH ARTICLE Structure of the Collision Zone Between the Nazca Ridge 10.1029/2019TC005637 and the Peruvian Convergent Margin: Geodynamic Key Points: • The Nazca Ridge hosts an and Seismotectonic Implications overthickened lower crust E. Contreras‐Reyes1 , P. Muñoz‐Linford2, V. Cortés‐Rivas1, J. P. Bello‐González3, J. A. Ruiz1, (10–14 km) formed in an on‐ridge 4 setting (hot spot plume near a and A. Krabbenhoeft spreading center) 1 2 • The Nazca Ridge correlates with a Departamento de Geofísica, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Santiago, Chile, Centro prominent continental slope scarp I‐MAR, Universidad de los Lagos, Puerto Montt, Chile, 3Grupo Minero Las Cenizas, Taltal, Chile, 4GEOMAR‐Helmholtz bounded by a narrow and uplifted Centre for Ocean Research, Kiel, Germany continental shelf • The Nazca Ridge has behaved as a seismic asperity for moderate earthquakes (e.g., 1996 Mw 7.7 and Abstract We study the structure and tectonics of the collision zone between the Nazca Ridge (NR) and 2011 Mw 6.9) nucleating at depths the Peruvian margin constrained by seismic, gravimetric, bathymetric, and natural seismological data. >20 km The NR was formed in an on‐ridge setting, and it is characterized by a smooth and broad shallow seafloor (swell) with an estimated buoyancy flux of ~7 Mg/s. The seismic results show that the NR hosts an Supporting Information: – – • Supporting Information S1 oceanic lower crust 10 14 km thick with velocities of 7.2 7.5 km/s suggesting intrusion of magmatic material from the hot spot plume to the oceanic plate. Our results show evidence for subduction erosion in the frontal part of the margin likely enhanced by the collision of the NR. -
The High Pressure Belt in the Grenville Province: 75 Architecture, Timing, and Exhumation1
100 867 100 95 95 75 The High Pressure belt in the Grenville Province: 75 architecture, timing, and exhumation1 25 25 Toby Rivers, John Ketchum, Aphrodite Indares, and Andrew Hynes 5 5 0 0 Abstract: We propose that the Grenvillian allochthonous terranes may be grouped into High Pressure (HP) and Low Pressure (LP) belts and examine the HP belt in detail in the western and central Grenville Province. The HP belt is developed in Paleo- and Mesoproterozoic rocks of the pre-Grenvillian Laurentian margin and characterized by Grenvillian eclogite and co-facial HP granulite in mafic rocks. Pressure–temperature (P–T) estimates for eclogite-facies conditions in well-preserved assemblages are about 1800 MPa and 850°C. In the central Grenville Province, HP rocks formed at -1060–1040 Ma and underwent a single stage of unroofing with transport into the upper crust by -1020 Ma, whereas farther west they underwent two stages of unroofing separated by penetrative mid-crustal recrystallization before transport to the upper crust at -1020 Ma. Unroofing processes were comparable in the two areas, involving both thrusting and extensional faulting in an orogen propagating into its foreland by understacking. In detail, thrusting episodes preceded extension in the western Grenville Province, whereas in the central Grenville Province, they were coeval, resulting in unroofing by tectonic extrusion. In the central Grenville Province, the footwall ramp is well preserved, but any former ramp in the western Grenville Province was obliterated by later lower crustal extensional flow. Continuation of the HP belt into the eastern Grenville Province is not established, but likely on geological grounds. -
Tectonic Segmentation of the North Andean Margin: Impact of the Carnegie Ridge Collision
ELSEVIER Earth and Planetary Science Letters 168 (1999) 255±270 Tectonic segmentation of the North Andean margin: impact of the Carnegie Ridge collision M.-A. Gutscher a,Ł, J. Malavieille a, S. Lallemand a, J.-Y. Collot b a Laboratoire de GeÂophysique et Tectonique, UMR 5573, Universite Montpellier II, Place E. Bataillon, F-34095 Montpellier, Cedex 5, France b IRD, Geosciences Azur, Villefranche-sur-Mer, France Received 17 July 1998; accepted 2 March 1999 Abstract The North Andean convergent margin is a region of intense crustal deformation, with six great subduction earthquakes Mw ½ 7:8 this century. The regional pattern of seismicity and volcanism shows a high degree of segmentation along strike of the Andes. Segments of steep slab subduction alternate with aseismic regions and segments of ¯at slab subduction. This segmentation is related to heterogeneity on the subducting Nazca Plate. In particular, the in¯uence of the Carnegie Ridge collision is investigated. Four distinct seismotectonic regions can be distinguished: Region 1 ± from 6ëN to 2.5ëN with steep ESE-dipping subduction and a narrow volcanic arc; Region 2 ± from 2.5ëN to 1ëS showing an intermediate-depth seismic gap and a broad volcanic arc; Region 3 ± from 1ëS to 2ëS with steep NE-dipping subduction, and a narrow volcanic arc; Region 4 ± south of 2ëS with ¯at subduction and no modern volcanic arc. The Carnegie Ridge has been colliding with the margin since at least 2 Ma based on examination of the basement uplift signal along trench-parallel transects. The subducted prolongation of Carnegie Ridge may extend up to 500 km from the trench as suggested by the seismic gap and the perturbed, broad volcanic arc. -
Backarc Origin for Neoarchean Ultrahigh-Temperature Metamorphism, Eclogitization, and Orogenic Root Growth
Backarc origin for Neoarchean ultrahigh-temperature metamorphism, eclogitization, and orogenic root growth Gregory Dumond1*, Michael L. Williams2, Julia A. Baldwin3, and Michael J. Jercinovic2 1Department of Geosciences, University of Arkansas, Fayetteville, Arkansas 72701, USA 2Department of Geosciences, University of Massachusetts, Amherst, Massachusetts 01003-9297, USA 3Department of Geosciences, University of Montana, Missoula, Montana 59812-1296, USA ABSTRACT modeling of Thompson et al. (2001) and provide evidence for crustal Contraction of continental crust during orogeny results in elevated root growth associated with high-P metamorphism of mid-oceanic ridge topography at the surface and a root at depth. Thermomechanical basalt (MORB)–like mafc intrusions. Intraplating of these intrusions models suggest that root growth is enhanced by thickening of ther- facilitated partial melting and UHT metamorphism of peraluminous supra- mally softened thin lithosphere. A >400 km2 region of Archean gneiss crustal host rocks (Dumond et al., 2015). We use Th–U–total Pb monazite in the Athabasca granulite terrane in the Canadian shield contains petrochronology to constrain the timing of high-P melting preserved in abundant mafc sills with mid-oceanic ridge basalt–like chemistry. felsic granulite paragneiss in contact with a previously dated eclogite Heat from the sills facilitated melting of supracrustal host rocks along sill that yielded U-Pb zircon dates of 2.54 Ga and 1.90 Ga (Baldwin et a prograde pressure-temperature (P-T) path culminating at P > 1.4 al., 2004). These results are combined with bulk-rock geochemistry for GPa and T > 950 °C in the Neoarchean. A basalt sill, converted to mafc granulites and eclogite near the base of the Upper Deck to infer a eclogite near the base of the domain, exhibits positive Eu anomalies backarc origin for a Neoarchean orogenic root. -
Andean Flat-Slab Subduction Through Time
Andean flat-slab subduction through time VICTOR A. RAMOS & ANDRE´ S FOLGUERA* Laboratorio de Tecto´nica Andina, Universidad de Buenos Aires – CONICET *Corresponding author (e-mail: [email protected]) Abstract: The analysis of magmatic distribution, basin formation, tectonic evolution and structural styles of different segments of the Andes shows that most of the Andes have experienced a stage of flat subduction. Evidence is presented here for a wide range of regions throughout the Andes, including the three present flat-slab segments (Pampean, Peruvian, Bucaramanga), three incipient flat-slab segments (‘Carnegie’, Guan˜acos, ‘Tehuantepec’), three older and no longer active Cenozoic flat-slab segments (Altiplano, Puna, Payenia), and an inferred Palaeozoic flat- slab segment (Early Permian ‘San Rafael’). Based on the present characteristics of the Pampean flat slab, combined with the Peruvian and Bucaramanga segments, a pattern of geological processes can be attributed to slab shallowing and steepening. This pattern permits recognition of other older Cenozoic subhorizontal subduction zones throughout the Andes. Based on crustal thickness, two different settings of slab steepening are proposed. Slab steepening under thick crust leads to dela- mination, basaltic underplating, lower crustal melting, extension and widespread rhyolitic volcan- ism, as seen in the caldera formation and huge ignimbritic fields of the Altiplano and Puna segments. On the other hand, when steepening affects thin crust, extension and extensive within-plate basaltic flows reach the surface, forming large volcanic provinces, such as Payenia in the southern Andes. This last case has very limited crustal melt along the axial part of the Andean roots, which shows incipient delamination.