Abstract
Modern seismic imaging methods were used to study the subduction processes of the South American convergent margin. The data came from reflection and from wide-angle/refraction experiments acquired within the framework of the Collaborative Research Center SFB267 ‘Deformation Processes in the Andes’. Two areas of differing character and subduction type were investigated: an erosive margin to the north (19–26° S) and an accretionary margin to the south (36–40° S). Results from different seismic models yield three main transects that give an overall impression about the internal structure below the Chilean margin. At the erosive margin, we find that the upper part of the subducting oceanic lithosphere is characterized by a horst-and-graben structure that coincides with the coupling zone between the plates. Strong coupling between oceanic crust and fore-arc in the case of a horst-continent collision is also indicated by plate-parallel faults beneath the lower continental slope, which we interpret as the upper parts of the subduction channel. In this context, the subduction channel represents the downgoing Nazca Plate as well as those portions of the continental crust which moved landward. Low seismic velocities below the coastline also represent parts of the subduction channel and of the hydrofractured base of the upper crust near the plate interface. Between 45 and 60 km depth, a double reflection zone marks the upper and lower boundary of the subducted oceanic crust. Off southern Chile, the ocean bottom is characterized by relatively smooth morphology. In contrast, in the south, the trench is filled with sediments and contains an axial channel (Figs. 7.16 to 7.18) extending in N-S direction along the trench axis within the investigation area. The periodicity of the reflected seismic signal within these sediments correlates with the main glacial cycle during the Quaternary. The recent accretionary wedge is built up from strongly heterogeneous unconsolidated sediments. Frontal accretion takes place within the southern working area except for the region around the Arauco Peninsula, which shows uplift due to basal accretion and antiformal stacking. Below the Coastal Cordillera, the heterogeneity of the modern accretionary wedge and the antiformal stack structure of the Permo-Triassic accretionary wedge complicate imaging at depths greater than about 30 km. Thus, we obtain an image of the top of the subduction channel as a thin reflector segment only to about 25 km depth.
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References
ANCORP Working Group (1999) Seismic reflection image revealing offset of Andean subduction zone earthquake locations into oceanic mantle. Nature 397:341–344
ANCORP Working Group (2003) Seismic imaging of a convergent margin and plateau in the central Andes (Andean Continental Research Project 1996 (ANCORP’96). J Geophys Res 108(B7): doi 10.1029/2002JB001771
Asch G, Schurr B, Bohm M, Yuan X, Haberland C, Heit B, Kind R, Woelbern I, Bataille K, Comte D, Pardo M, Viramonte J, Rietbrock A, Giese P (2006) Seismological studies of the Central and Southern Andes. In: Oncken O, Chong G, Franz G, Giese P, Götze H-J, Ramos VA, Strecker MR, Wigger P (eds) The Andes — active subduction orogeny. Frontiers in Earth Science Series, Vol 1. Springer-Verlag, Berlin Heidelberg New York, pp 443–458, this volume
Bangs NLB, Cande SC (1997) Episodic development of a convergent margin inferred from structures and processes along the southern Chile margin. Tectonics 16(3):489–503
Bangs NLB, Shipley TH (1999) Fluid accumulation and channeling along the northern Barbados Ridge decollement thrust. J Geophys Res 104(B9):20399–20414
Bohm M, Lüth S, Echtler H, Asch G, Bataille K, Bruhn C, Rietbrock A, Wigger P (2002) The Southern Andes between 36° and 40° latitude: seismicity and average seismic velocities. Tectonophysics 356(4):275–28
Brasse H, Soyer W (2001) A magnetotelluric study in the Southern Chilean Andes. Geophys Res Lett 28(19):3757–3760
Brasse H, Lezaeta P, Rath V, Schwalenberg K, Soyer W, Haak V (2002) The Bolivian Altiplano conductivity anomaly. J Geophys Res 107(B5): doi 10.1029/2001JB000391
Buske S, Lüth S, Meyer H, Patzig R, Reichert C, Shapiro SA, Wigger P, Yoon M (2002) Broad depth range seismic imaging of the subducted Nazca Slab, North Chile. Tectonophysics 350(4):273–282
Cifuentes IL (1989) The 1960 Chilean Earthquakes. J Geophys Res 94(B1):665–680
Clift P, Vannucchi P (2004) Controls on tectonic accretion versus erosion in subduction zones: Implications for the origin and recycling of the continental crust. Rev Geophys 42(2): doi 10.1029/ 2003RG000127
Davis D, Suppe J, Dahlen FA (1983) Mechanics of fold-and-thrust belts and accretionary wedges. J Geophys Res 88(B2):1153–1172
Echternacht F, Tauber S, Eisel, M., Brasse H, Schwarz G, Haak V (1997) Electromagnetic study of the active continental margin in northern Chile. Phys Earth Planet Int 102:69–88
Flüh ER, Grotzki N, Husen S, Ranero CR, Reichert C, Vidal N (1997) Seismic refraction investigations of the deep crustal structure offshore Chile. VIII Congreso Geologico Chileno, Antofagasta, Chile
Graeber FM, Asch G (1999) Three-dimensional models of P-wave velocity and P-to S-velocity ratio in the southern Central Andes by simultaneous inversion of local earthquake data. J Geophys Res 104(B9):20237–20256
Günther A, Haschke M, Reutter K-J, Scheuber E (1997) Repeated reactivation of an ancient fault zone under changing kinematic conditions: the Sierra de Moreno fault system (SMFS) (North Chilean Precordillera). Actas VIII Congreso Geologico Chileno 1:85–89
Gutscher MA, Kukowski N, Malavieille J, Lallemand S (1996) Cyclical behavior of thrust wedges: insights from high basal friction sandbox experiments. Geology 24:135–138
Haberland C, Rietbrock A (2001) Attenuation tomography in the western Central Andes: a detailed insight into the structure of a magmatic arc. J Geophys Res 106(B6):11151–11167
Hartley AJ, Chong G (2002) Late Pliocene age for the Atacama desert: implications for the desertification of western South America. Geology 30:43–46
Hervé F (1994) The Southern Andes between 39° and 44°S latitude: the geological signature of a transpressive tectonic regime related to a magmatic arc. In: Reutter K-J, Scheuber E, Wigger P (eds) Tectonics of the Southern Central Andes. Springer Verlag, Berlin Heidelberg New York, pp 223–24
Hinz K, Adam J, Bargeloh HO, Block M, Damm V, Dohmann H, Fritsch J, Kewitsch P, Krieger K, Neben S, Puskeppeleit K, Reichert C, Schlumschinski B, Schrader U, Schreckenberger B, Sievers J, Jiminez HN (1995) Crustal investigations off-and onshore Nazca/ Central Andes (CINCA), SONNE cruise 104, leg 1–3. Technical Report BGR 113.998, Bundesanstalt für Geowissenschaften und Rohstoffe, Hannover
Husen S, Kissling E, Flueh E, Asch G (1999) Accurate hypocentre determination in the seismogenic zone of the subducting Nazca Plate in Northern Chile using a combined on-/offshore network. Geophys J Int 138(3):687–701
Isacks BL (1988) Uplift of the Central Andean plateau and bending of the bolivian orocline. J Geophys Res 93(B4):3211–3231
Jarrard RD (1986) Relations among subduction parameters. Rev Geophys 24(2):217–283
Jensen OL, Jordan TE, Ramos VA, Allmendinger RW, Isacks B (1984) Andean tectonics related to geometry of subducted Nazca Plate: discussion and reply. Geol Soc Am Bull 95(7):877–880
Jordan TE, Isacks BL, Allmendinger RW, Brewer JA, Ramos VA, Ando C (1983) Andean tectonics related to geometry of subducted Nazca Plate. Geol Soc Am Bull 94(3):341–361
Jordan TE, Burns WM, Veiga R, Pángaro F, Copeland P, Kelley S, Mpodozis C (2001) Extension and basin formation in the southern Andes caused by increased convergence rate: a mid-Cenozoic trigger for the Andes. Tectonics 20(3):301–324
Kanamori H, Cipar JJ (1974) Focal process of the great Chilean earthquake May 22, 1960. Phys Earth Planet Int 9:128–136
Klotz J, Khazaradze G, Angermann D, Reigber C, Perdomo R, and Cifuentes O (2001) Earthquake cycle dominates contemporary crustal deformation in Central and Southern Andes. Earth Planet Sci Lett 193(3–4):437–446
Krawczyk CM, SPOC Team (2003) Amphibious seismic survey images plate interface at 1960 Chile earthquake. EOS 84(32):301, 304-305
Krawczyk CM, Stiller M, Lüth S, Mechie J, SPOC Research Group (2003) Image of the seismogenic coupling zone in Central Chile: the amphibious experiment SPOC (Subduction Processes Off Chile). EGSAGU-EGU Joint Assembly, Nice, France, EAE03-A-01228
Krawczyk CM, Lohrmann J, Oncken O, Stiller M, Mechie J, Bataille K, SPOC Research Group (2004) Basal accretion as mechanism for crustal growth in the 1960 Chile earthquake area. Geophys Res Abs 6, EGU04-A-02306
Krawczyk CM, Mechie J, Lüth S, Tašárová Z, Wigger P, Stiller M, Brasse H, Echtler HP, Araneda M, Bataille K (2006) Geophysical signatures and active tectonics at the south-central Chilean margin. In: Oncken O, Chong G, Franz G, Giese P, Götze H-J, Ramos VA, Strecker MR, Wigger P (eds) The Andes — active subduction orogeny. Frontiers in Earth Science Series, Vol 1. Springer-Verlag, Berlin Heidelberg New York, pp 171–192, this volume
Lessel K (1997) Die Krustenstruktur der Zentralen Anden in Nordchile (21–24°S), abgeleitet aus 3D-Modellierungen refraktionsseismischer Daten. Berliner Geowiss. Abh., Reihe B, Band 31
Lohrmann J, Kukowsky N, Adam J, Echtler H, Oncken O (2000) Identification of controlling parameters of the accretionary southern Chilean margin (38–40°S) with analogue models. 17. Geowiss. Lateinamerika-Kolloquium, Stuttgart
Lohrmann J, Kukowski N, Krawczyk CM, Oncken O, Sick C, Sobiesiak M, Rietbrock A (2006) Subduction channel evolution in brittle fore-arc wedges — a combined study with scaled sandbox experiments, seismological and reflection seismic data and geological field evidence. In: Oncken O, Chong G, Franz G, Giese P, Götze H-J, Ramos VA, Strecker MR, Wigger P (eds) The Andes — active subduction orogeny. Frontiers in Earth Science Series, Vol 1. Springer-Verlag, Berlin Heidelberg New York, pp 237–262, this volume
Lüth S (2000) Ergebnisse weitwinkelseismischer Untersuchungen und die Struktur der Kruste auf einer Traverse über die Zentralen Anden bei 21°S. Berliner Geowiss. Abh., Reihe B, Band 37
Lüth S, SPOC Research Group (2003) Subduction Processes Off Chile (SPOC) — results from the amphibious wide-angle seismic experiment across the Chilean subduction zone. EGS-AGU-EGU Joint Assembly, Nice, France, EAE03-A-04129
Lüth S, Wigger P, Mechie J, Stiller M, Krawczyk C, Bataille K, Reichert C, Flueh E (2004) The crustal structure of the Chilean forearc between 36° and 40°S from combined offshore and onshore seismic wide-angle measurements — SPOC (2001 Bolletino di Geofisica Teorica ed Aplicata, Special Issue, GeoSur 2004
Lüth S, Wigger P, ISSA Research Group (2003) A crustal model along 39° from a seismic refraction profile ISSA2000. Rev Geol Chile, 30(1):83–101
Patzig R (2000) Lokalbeben-Tomographie der Umgebung von Antofagasta (Nordchile) sowie Betrachtungen der Magnituden-Häufigkeits-Parameter in dieser Region. PhD thesis, Freie Universität Berlin
Patzig R, Shapiro, S, Asch, G, Giese, P, Wigger, P (2002) Seismogenic plane of the northern Andean Subduction Zone from aftershocks of the Antofagasta (Chile) 1995 earthquake. Geoph Res Let 29: doi 10.1029/2001GL013244
Patzwahl R (1998) Plattengeometrie und Krustenstruktur am Kontinentalrand Nord-Chiles aus Weitwinkelseismischen Messungen. Berliner Geowiss. Abh., Reihe B, Band 3
Patzwahl R, Mechie J, Schulze A, Giese P (1999) 2-D-velocity models of the Nazca Plate subduction zone between 19.5°S and 25°S from wide-angle seismic measurements during the CINCA’95 project. J Geophys Res 104(B4):7293–731
Pelz K (2000) Tektonische Erosion am zentralandinen Forearc (20°–24°S). PhD thesis, Freie Universität Berlin
Plafker G, Savage JC (1970) Mechanism of the Chilean earthquakes of May 21 and 22, 1960. Geol Soc Am Bull 81(4):1001–1030
Ranero CR, von Huene R (2000) Subduction erosion along the Middle America convergent margin. Nature 404:748–755
Rauch K (2004) Zyklische Reflexionen terrigener Sedimente im Peru-Chile-Graben. PhD thesis, Freie Universität Berlin
Rauch K (2005) Cyclicity of Peru-Chile trench sediments between 36 and 38 degrees S: A footprint of paleoclimatic variations? Geoph Res Let 32: doi:10.1029/2004GL022196
Reichert C, Schreckenberger B, Adam J, Barckhausen U, Bargeloh HO, Behrens T, Block M, Bönnemann C, Canuta Canuta J, Celedon Canessa V, Contreras Gonzales S, Damaske D, Diaz Naveas J, Franke D, Gaedicke C, Giglio Munoz S, Hermosilla Jarpa A, Kallaus G, Kewitsch P, Krawczyk CM, Kus J, Ladage S, Lindemann FM, Ranero C, Schrader U, Sepulveda J, Sievers J, Surburg E, Urbina Arce O, Zeibig M (2001) Subduction processes off Chile (SPOC) SONNE cruise SO161 leg 2 & 3. Technical Report BMBF Forschungsvorhaben 03G0161A, Bundesanstalt für Geowissenschaften und Rohstoffe, Hannover
Reichert C, SPOC Scientific Shipboard Party (2002) Subduction processes off Chile: initial geophysical results of SONNE Cruise SO-161(2+3). Geophys Res Abs EGS02-A-05338
Reichert C, Schreckenberger B, Flueh ER, Krawczyk C, SO161-2/3-Bordwissenschaftler (2003) Subduktionsvariabilität am aktiven Kontinentrand Chiles (SO 161-2 und-3). In: Tanner B (ed) Statusseminar 2003, Meeresforschung mit FS SONNE. Forschungszentrum Jülich, Projektträger des BMBF und BMWi, Bereich MGS, Außenstelle Warnemünde, Hamburg, Germany, pp 39–42
Rietbrock A, Haberland C (2001) A tear in the subducting Nazca slab: Evidence from local earthquake tomography and high precision hypocenters. EOS 82(47) Fall Meeting Supplement T31A-0822
Rietbrock A, Waldhauser F (2004) A narrowly spaced double-seismic zone in the subducting Nazca plate. Geophys Res Lett 31(10): doi 10.1029/2004GL019610
Scheuber E, Giese P (1999) Architecture of the Central Andes — a compilation of geoscientific data along a transect at 21°S. J South Am Earth Sci 12:103–107
Scheuber E, Reutter K-J (1992) Magmatic arc tectonics in the Central Andes between 21° and 25°S. Tectonophysics 205:127–14
Scheuber E, Bogdanic T, Jensen A, Reutter K-J (1994) Tectonic development of the North Chilean Andes in relation to plate convergence since the Jurassic. In: Reutter K-J, Scheuber E, Wigger P (eds) Tectonics of the Southern Central Andes. Springer Verlag, Berlin Heidelberg New York, pp 121–140
Schmitz M, Lessel K, Giese P, Wigger P, Araneda M, Bribach J, Graeber FM, Grunewald S, Haberland C, Lüth S, Röwer P, Ryberg T, Schulze A (1999) The crustal structure beneath the Central Andean forearc and magmatic arc as derived from seismic studies — the PISCO 94 experiment in northern Chile (21°–23°S). J South Am Earth Sci 12:237–2
Sick CMA (2005) Structural investigations off Chile: Kirchhoff Prestack depth migration versus Fresnel volume migration. PhD thesis, Freie Universität Berlin
Springer MH, Förster A (1998) Heat flow density across the Central Andean subduction zone. Tectonophysics 291:123–139
Stern RJ (2002) Subduction zones. Rev Geophys 40(4): doi 10.1029/ 2001RG000108
Tebbens SF, Cande SC (1997) Southeast Pacific tectonic evolution from the early Oligocene to Present. J Geophys Res 102:12061–12084
Thornburg T, Kulm LD (1987) Sedimentation in the Chile trench: depositional morphologies, lithofacies and stratigraphy. Geol Soc Am Bull 98:33–52
von Huene R, Ranero CR (2003) Subduction erosion and basal friction along the sediment-starved convergent margin off Antofagasta, Chile. J Geophys Res 108(B2): doi 10.1029/2001JB001596
von Huene R, Scholl DW (1991) Observations at convergent margins concerning sediment subduction, subduction erosion, and the growth of continental crust. Rev Geophys 29:279–316
von Huene R, Weinrebe W, Heeren F (1999) Subduction erosion along the North Chile margin. J Geodyn 27:345–358
Wigger P, Baldzuhn S, Giese P, Heinsohn WD, Schmitz M, Araneda M, Martínez E, Ricaldi E, Viramonte A (1994) Variations of the crustal structure of the Southern Central Andes deduced from seismic refraction investigations. In: Reutter K-J, Scheuber E, Wigger P (eds) Tectonics of the Southern Central Andes. Springer Verlag, Berlin Heidelberg New York, pp 23–48
Yanez G, Cembrano J, Pardo M, Ranero C, Selles D (2002) The Challenger-Juan Fernandez-Maipo major tectonic transition of the Nazca-Andean subduction system at 33–34°S: geodynamic evidence and implications. J South Am Earth Sci 15(1):23–38
Yoon M (2001) Application of true amplitude prestack migration to a deep seismic dataset (ANCORP, Chile & Bolivia). Diploma Thesis, Freie Universität Berlin
Yoon M (2005) Deep seismic imaging in the presence of heterogeneous overburden: numerical modeling and case studies from the Central and Southern Andes. PhD thesis, Freie Universität Berlin
Yoon M, Buske S, Schulze R, Lüth S, Shapiro SA, Stiller M, Wigger P (2003) Alongstrike variations of crustal reflectivity related to the Andean subduction process. Geophys Res Lett, 30(4):1160, doi 10.1029/2002GL015848
Yuan X, Sobolev SV, Kind R, Oncken O, Bock G, Asch G, Schurr B, Graeber F, Rudloff A, Hanka W, Wylegalla K, Tibi R, Haberland C, Rietbrok A, Giese P, Wigger P, Röwer P, Zandt G, Beck S, Wallace T, Pardo MC (2000) Subduction and collision process in the Central Andes constrained by converted seismic phases. Nature 408: 958–961
Yuan X, Asch G, Bataille K, Bock G, Bohm M, Echtler H, Kind R, Oncken O, Wölbern I (2004) Deep seismic images of the Southern Andes. In: Kay SM, Ramos VA (eds) Late cretaceous to recent magmatism and tectonism of the Southern Andean Margin at the latitude of the Neuquen Basin (36–39°S) Geol Soc Am Spec P, submitted
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Sick, C. et al. (2006). Seismic Images of Accretive and Erosive Subduction Zones from the Chilean Margin. In: Oncken, O., et al. The Andes. Frontiers in Earth Sciences. Springer, Berlin, Heidelberg . https://doi.org/10.1007/978-3-540-48684-8_7
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