Structural geology of the Fuegian Andes and Magallanes fold-and-thrust belt - Tierra del Fuego Island

Authors

  • M. MENICHETTI stituto di Scienze della Terra, Università di UrbinoCampus Científico Universitario, 61029 Urbino, Italy.
  • E. LODOLO Istituto Nazionale di Oceanografia e di Geofisica Sperimentale34010 Sgonico,Trieste, Italy.
  • A. TASSONE CONICET- INGEODAV, Dept. de Geología, FCEyN, Universidad de Buenos Aires, Argentina Ciudad Universitaria, 1428 Buenos Aires, Argentina.

DOI:

https://doi.org/10.1344/104.000000239

Keywords:

Fuengian Andes, Structural geology, Tectonics, Neotectonics, Andes

Abstract

A synthesis of the structural geology of the Tierra del Fuego Island, which integrates a new data set derived from field surveys and literature data of the last few years, is presented here. The main geological features of the region developed during the Mesozoic-Cenozoic Andean orogenic cycle that started in the Middle to Late Jurassic with a back-arc extension, crustal stretching and widespread volcanism, related to the break-up of Gondwanaland. An extensional fault system deriving from the mechanical and thermal subsidence led the evolution of the Rocas Verdes marginal basin, which hosts the upper Jurassic volcanoclastic rocks, the lower Cretaceous turbiditic sequences and few isolated elongated ophiolitic complexes. From the Late Cretaceous onward, the orogenic cycle of the Fuegian Andes continued with the shortening and inversion of the back-arc margin through horizontal contraction and crustal thickening. The uplift of the Cordillera, the emplacement of plutonic rocks, and the intercontinental polyphase deformation resulted from thick-skinned tectonics. The thrust system developed from its deeper roots, where the Palaeozoic basement was involved in compressive deformation, and propagated to the shallower stratigraphic levels of the northward verging Magallanes fold-and-thrust belt. The Magallanes foreland basin developed in front of the orogenic wedge that records at least four syntectonic angular unconformities from Late Cretaceous to Lower Miocene. During the Late Cretaceous Andean compression, three distinct phases of penetrative ductile deformation defined by low-greenschist facies assemblages took place, both in the basement and in the cover units. These deformations are related to a single metamorphic event with foliation development, as observed from microscopic analysis of the schist in the Ushuaia area. The first foliation S1 is preserved either as relic sericite microfolds between microlithons of the dominant S2, or as early refolded veins of recrystallized quartz. The S2 foliation is defined by oriented white mica. The crenulation of S2, which is related to D3 and occurs in most strained zones, becomes a pressure solution S3 spaced foliation, lined by opaque minerals. From the Palaeogene to the present, EW sinistral wrench tectonics affected the region as a component of the relative motion between South America and the Antarctic Peninsula. This strike-slip activity is well documented from the Carbajal valley to the Canal de Beagle region south of the Magallanes-Fagnano transform fault system. Restraining bends and overlapping step-over geometry characterize few sectors of the strike-slip faults with pop-ups, pressure ridges and uplifted slivers of crust. Releasing step-over along the transform fault system, both in on-shore and off-shore zones, formed several elongated pull-apart basins with many tens of km in length and a few km in width. The Lago Fagnano represents the main morphotectonic expression of this structural setting. A N-S geological cross-section through the Fuegian Andes synthesizes all the geological and geophysical data. The major stacks of internal thick skinned basement involved in the thrusting are high-grade Upper Palaeozoic to Lower Tertiary metamorphic rocks. The geometry of the thrust complex is an upright, south plunging monocline of moderately tilted sedimentary cover strata, as well as related thrusts, faults and chevron folds involving the Upper Jurassic and Cretaceous rocks. The orogenic shortening of the Fuegian Andes, including the Cordillera and the Magallanes fold-and-thrust belt, reaches few hundred kilometres with a left-lateral wrenching component of many tens of meters. The Tierra del Fuego Island is characterized by low seismicity (M<3.5) and shallow crustal earthquakes. The southern part presents strong morphological evidence of the Quaternary activity of the E-W left-lateral strike-slip faults, with a present deformation pattern (DGPS) with a horizontal slip component of about 6 mm/year. Moreover, the northern sector of the Island is affected by extensional tectonics related to the normal fault systems of the eastern arms of the Magallanes Strait.

References

Acevedo, R.D., Linares, E., Ostera, H., Valín-Alberdi, M.L., 2002. Hornblendita Ushuaia (Tierra del Fuego): Petrografía, geoquímica y geocronología. Revista de la Asociación Geológica Argentina, 57(2), 133-142.

Álvarez-Marrón, J., McClay, K.R., Harambour, S., Rojas, L., Skarmeta, J., 1993. Geometry and evolution of the frontal part of the Magallanes foreland thrust and fold belt (Vicuña area), Tierra del Fuego, southern Chile. American Association Petroleum Geologist Bulletin, 11, 1904-1921.

Angelier, J., Goguel, J., 1979. Sur une méthode simple de determination des axes principaux des contraintes por une population de failles. Comptes Rendus Royale Académie Sciences de Paris, 288, 307-310.

Barker, P.F., 2001. Scotia Sea regional tectonic evolution: implications for mantle flow and paleocirculation. Earth-Science Reviews, 55, 1-39.

Bartole, R., Colizza, E., De Muro, S., Colautti, W., 2000. The Pacific Entrance of the Magellan Strait: Preliminary results of a seismic and sampling survey. Terra Antartica Reports, 4, 81-94.

Biddle, K.T., Snavely III, P.D., Uliana, M.A., 1996. Plateau de las Malvinas. In: Ramos, V.A., Turic, M.A. (eds.). Geología y recursos naturales de la plataforma continental Argentina. 13 Congreso Geológico Argentino y 3 Congreso de Exploración de Hidrocarburos, Relatorio, 225-252.

Biddle, K.T., Uliana, M.A., Mitchum, R.M., Fitzgerald, M.G., Wright, R.C., 1986. The stratigraphic and structural evolution of the central and eastern Magallanes Basin, southern South America. International Association of Sedimentologists, Special Publication, 8, 41-61.

Bonarelli, G., 1917. Tierra del Fuego y sus turberas. Anales del Ministerio de Agricultura de la Nación (Argentina), 12, 3, 1-86.

Bruhn, R.L., 1979. Rock structures during back-arc basin deformation in the Andes of Tierra del Fuego. Geological Society of America Bulletin, 90, 998-1012.

Cagnolatti, M., Covellone, G., Erlicher, J., Fantin, F., 1987. Fallamiento y plegamiento de cobertura al suroeste del Río Grande, Cuenca Austral- Tierra del Fuego. 10 Congreso Geológico Argentino, 1, 149-152.

Caminos, R., 1980. Cordillera Fueguina. Córdoba, Geología Regional Argentina, 2, 1463-1501.

Caminos, R., Haller, M., Lapido, J., Lizuain, O., Page, A., Ramos, V.A., 1981. Reconocimiento geológico de los Andes Fueguinos. Territorio Nacional de Tierra del Fuego. VIII Congreso Geológico Argentino, San Luis, Argentina, Actas, 3, 759-786.

Cecioni, G., 1956. Primeras noticias sobre La existencia del Paleozoico Superior en el Archipiélago Patagonico entre los

paralelos 50° y 52°S. Universidad de Chile, Facultad de Ciencias Físicas y Matemáticas, Anales, 13, 183-202.

Cunningham, W.D., 1993. Strike-slip faults in the southernmost Andes and the development of the Patagonian orocline. Tectonics, 12(1), 169-186.

Cunningham, W.D., 1995. Orogenesis at the southern tip of the Americas: the structural evolution of the Cordillera Darwin

metamorphic complex, southernmost Chile. Tectonophysics, 244, 197-229.

Cunningham, W.D., Dalziel, I.W.D., Lee, T.Y., Lawver, L.A., 1995. Southernmost South America–Antarctic Peninsula relative plate motions since 84 Ma: implications for the tectonic evolution of the Scotia arc region. Journal of Geophysical Research, 100, B5, 8257-8266.

Dalziel, I.W.D., 1981. Back-arc extension in the southern Andes: A review and critical reappraisal. Phylosophical Transactions of the Royal Society A-300, 319-335 .

Dalziel, I.W.D., 1985. Collision and Cordilleran orogenesis: an Andean perspective. In: Coward, M.P., Ries, A.C. (eds.). Collision Tectonics. Geological Society of London Special Publication, 19, 389-404.

Dalziel, I.W.D., Brown R.L., 1989. Tectonic denudation of the Darwin metamorphic core complex in the Andes of Tierra del Fuego, southernmost Chile: implications for Cordilleran orogenesis. Geology, 17, 699-703.

Dalziel, I.W.D., Elliot, D.H., 1973. The Scotia Arc and Antarctic margin. In:. Nairn, A.E.M., Stehli, F.G. (eds.). The Ocean Basin and Margin I. The South Atlantic, 171-245.

Dalziel, I.W.D., Forsythe, R.F., 1986. Andean evolution and the terrane concept. In: Howel, D.G. (ed.). Tectonostratigraphy Terranes of the Circum-Pacific Region. American Association Petroleum Geologist, Houston, 565-581.

Dalziel, I.W.D., Palmer, K.E., 1979. Progressive deformation and orogenic uplift at the southern extremity of the Andes. Geological Society of America Bulletin, 90, 259-280.

Dalziel, I.W.D., de Witt, M.J., Palmer, K.F., 1974. Fossil marginal basin in the southern Andes. Nature, 250, 291-294.

Del Cogliano, D., Perdomo, R., Hormaechea, J.L., 2000. Desplazamiento entre placas tectónicas en Tierra del Fuego. Actas de la XX Reunión Científica de la AAGG, Mendoza. DeMets, C., Gordon, R.G., Argus, D.F., Stein, F., 1990. Current plate motions. Geophysics Journal International, 101, 425-478.

De Paor, D.G., 1988. Balanced sections in thrust belts. Part I: Construction. American Association Petroleum Geologist Bulletin, 72(1), 73-90 .

Diraison, M., Cobbold, P.R., Gapais, D., Rossello, E.A., 1997. Magellan Strait: Part of a Neogene rift system. Geology, 25(8), 703-706.

Diraison, M., Cobbold, P.R., Gapais, D., Rossello, E.A., Le Corre, C., 2000. Cenozoic crustal tickening, wrenching and rifting in the foothills of the southernmost Andes. Tectonophysics, 316, 91-119.

Farr, T.G., Kobrick, M., 2000. Shuttle Radar Topography Mission produces a wealth of data. EOS American Geophysical Union, 81, 583-585.

Feraud, G., Alric, V., Fornari, M., Bertrand, H., Haller, M., 1999. 40Ar/39Ar dating of the Jurassic volcanic province of Patagonia: migrating magmatism related to Gondwana break-up and subduction. Earth and Planetary Science Letters, 172, 83-96.

Forsythe, R.D., Mpodozis, C., 1979. El Archipiélago Madre de Dios, Patagonia Occidental, Magallanes: rasgos generales de la estratigrafía y estructura del basamento pre Jurásico Superior. Revista Geológica de Chile, 7, 13-29.

Galeazzi, J.S., 1998. Structural and stratigraphic evolution of the Western Malvinas Basins. American Association Petroleum

Geologist Bulletin, 82(4), 596-636.

Geletti, R., Lodolo, E., Schreider, A.A., Polonia, A., 2005. Seismic structure and tectonics of the Schackleton Fracture zone (Drake passage, Scotia Sea). Marine Geophysical Researches, 26(1), 17-28.

Ghiglione, M.C., Ramos, V.A., 2005. Progression of deformation and sedimentation in the southernmost Andes. Tectonophysics, 405, 25-46.

Grunow, A.M., Dalziel, I.W.D., Harrison, T.M., Heizler, M.T., 1992. Structural geology and geochronology of subduction complexes along the margin of Gondwanaland: New data from the Antarctic Peninsula and southernmost Andes. Geological Society of America Bulletin, 104, 1497-1514.

Hanson, R.E., Wilson, T.J., 1991. Submarine rhyolitic volcanism in a Jurassic proto-marginal basin, southern Andes, Chile and Argentina. In: Harmon, R.S., Rapela, C.W. (eds.). Andean magmatism and its tectonic setting. Geological Society of America Special Paper, 265, 13-27.

Herron, E.M., Bruhn, R., Winslow, M., Chuaqui, L., 1977. Post Miocene tectonics of the margin of Southern Chile. In: Talwani, M., Pitman, W.C. III (eds.). Island Arcs, Deep Sea Trenches and Back Arc Basins. Washington, D.C., American Geophysical Union, 273-284.

Hervé, F., Calderón, M., Faúndez, V., 2008. The metamorphic complexes of the Patagonian and Fuegian Andes. Geologica Acta, 6(1), 43-53.

Hervé, F., Demant, A., Ramos, V.A., Pankhurst, R.J., Suárez, M., 2000. The Southern Andes. In: Cordani, U.G., Miliani, E.J., Thomaz Filho, A., Campos, D.A. (eds.). Tectonic Evolution of South America. Rio de Janeiro, 605-634.

Hervé, F., Nelson, E., Kawashita, K., Suárez, M., 1981. New isotopic ages and the timing of orogenic events in the Cordillera Darwin, southernmost Chilean Andes. Earth and Planetary Science Letters, 55, 257-265.

Jaschek, E., Sabbione, N., Sierra, P., 1982. Reubicación de sismos localizados en territorio argentino (1920-1963). Universidad de La Plata, Pub. Obs. Astr., Serie Geofísica, tomo XI, 1.

Jokat, W., Boebel, T., König, Meyer, U., 2003. Timing and geometry of early Gondwana breakup. Journal of Geophysical Research, 108 (B9), 2428, doi:10.1029/2002JB001802.

Katz, H.R., 1962. Fracture pattern and structural history in the sub-Andean belt of southernmost Chile. The Journal of Geology, 70(5), 595-603.

Katz, H.R., 1972. Plate tectonics-orogenic belt in the southeast Pacific. Nature, 237, p. 331.

Klepeis, K.A., 1994a. A relationship between uplift of the metamorphic core of the southernmost Andes and shortening in the Magallanes foreland fold and thrust belt, Tierra del Fuego. Tectonics, 13, 882-904.

Klepeis, K.A., 1994b. The Magallanes and Deseado fault zones: major segments of the South American-Scotia transform plate boundary in southernmost South America, Tierra del Fuego. Journal of Geophysical Research, 99, 22,001-22,014.

Klepeis, K.A., Austin, J.A., 1997. Contrasting styles of superposed deformation in the southernmost Andes. Tectonics, 16, 755-776.

Kohn, M.J., Spear, F.S., Harrison, T.M., Dalziel, I.W.D., 1995. 40Ar/39Ar geochronology and P-T-t paths from the Cordillera Darwin metamorphic complex, Tierra del Fuego, Chile. Journal of Metamorphic Geology, 13, 2, 251- 270.

Kohn, M.J., Spear, F.S., Dalziel, I.W.D., 1993. Metamorphic PT paths from the Cordillera Darwin: a core complex in Tierra del Fuego, Chile. Journal of Petrology, 34, 519-542.

Kranck, E.H., 1932. Geological Investigations in the Cordillera of Tierra del Fuego. Acta Geographica, 4, 2, 133 pp.

Kreamer P.E., 2003. Orogenic shortening and the origin of the Patagonian orocline (56°lat). Journal of South America Earth Sciences, 15, 731-748.

Lodolo, E., Lippai, H. Tassone, A., Zanolla, C., Menichetti, M., Hormaechea, J.L., 2007. Gravity map of the Isla Grande de Tierra del Fuego, and morphology of Lago Fagnano. Geologica Acta, 5(4), 307-314.

Lodolo, E., Menichetti, M., Tassone, A., Sterzai, P., 2002a. Morphostructure of the central-eastern Tierra del Fuego Island from geological data and remote-sensing images. EGS Stephan Mueller Special Pub. Series, 2, 1-16.

Lodolo, E., Menichetti, M., Tassone, A., Geletti, R., Sterzai, P., Lippai, H., Hormaechea, J.L., 2002b. Researchers target a continental transform Fault in Tierra del Fuego. EOS Transactions AGU, 83(1), 1-6.

Lodolo, E., Menichetti, M., Bartole, R., Ben Avram, Z., Tassone, A., Lippai, H., 2003. Magallanes-Fagnano continental transform fault (Tierra del Fuego, southernmost South America). Tectonics, 22(6), p. 1076, doi: 1029/ 2003TC0901500,2003.

Lomnitz, C., 1970. Major earthquakes and tsunamis in Chile during the period 1535 to 1955. Geologische Rundschau, 59, 938-960.

McClay, K., Dooley, T., 1995. Analogue models of pull-apart basins. Geology, 23, 711-714 .

Menichetti, A., Tassone, A., 2007. GEOSUR 2004. Mesozoic to Quaternary evolution of Tierra del Fuego and neighbouring

austral regions I. Geologica Acta, 5(4), 283-286.

Menichetti, M., Acevedo, R.D., Bujalesky, G.G., Cenni, M., Cerredo, M.E., Coronato, A., Hormachea, J.L., Lippai, H., Lodolo, E., Olivero, E.B., Rabassa, J., Tassone, A., 2004. Geology and geophysics of Isla Grande de Tierra del Fuego. Field-trip guide. Geosur 2004, Buenos Aires-Ushuaia, 39 pp.

Mukasa, S.B., Dalziel, I.W.D., 1996. Southernmost Andes and South Georgia Island, North Scotia Ridge: zircon U-Pb and muscovite TMAr/39Ar age constraints on tectonic evolution of southwestern Gondwanaland. Journal of South American

Earth Sciences, 9, 349-365.

Nelson, E.P., Dalziel, I.W.D., Milnes, A.G., 1980. Structural geology of the Cordillera Darwin - collisional style orogenesis in the southernmost Chilean Andes. Eclogae Geologicae Helvetiae, 73(3), 727-751.

Olivero, E.B., Malumián, N., 1999. Eocene stratigraphy of southeastern Tierra del Fuego Island, Argentina. American Association of Petroleum Geologist Bulletin, 83, 295-313.

Olivero, E.B., Malumián, D.R., 2008. Mesozoic-Cenozoic stratigraphy of the Fuegian Andes, Argentina. Geologica Acta, 6(1), 5-18.

Olivero, E.B., Martinioni, D.R., 1996. Sedimentología de las Formaciones Lemaire y Yahgán (Jurásico-Cretácico) en Tierra del Fuego. XIII Congreso Geológico Argentino and III Congreso de Hidrocarburos, Buenos Aires, Actas, II, 45-59.

Olivero, E.B., Martinioni, D.R., 2001. A review of the geology of the Fuegian Andes. Journal of South American Earth Sciences, 14, 175-188.

Olivero, E.B., Acevedo, R.D., Martinioni, D.R., 1997. Geología del Mesozoico de bahía Ensenada, Tierra del Fuego. Revista de la Asociación Geológica Argentina, 52(2), 169-179.

Pankhurst, R.J., Rapela, C.R., 1995. Production of Jurassic rhyolite by anatexis of the lower crust of Patagonia. Earth and Planetary Science Letters, 134, 23-36.

Pankhurst, R.J., Riley, T.R., Fanning, C.M., Kelley, S.P., 2000. Episodic silicic volcanism in Patagonia and the Antarctic Peninsula: chronology of magmatism associated with the break-up of Gondwana. Journal of Petrology, 41, 605–625.

Pelayo, A.M., Wiens, D.A., 1989. Seismotectonics and relative plate motions in the Scotia Arc region. Journal of Geophysical Research, 94, 7293-7320.

Polonia, A., Torelli, L., 2007. Antarctic/Scotia plate convergence off southernmost Chile. Geologica Acta, 5(4), 295-306.

Polonia, A., Brancolini, G., Torelli, L., Vera, E., 1999. Structural variability at the active continental margin off Southernmost

Chile. Journal of Geodynamics, 27, 289-307.

Ramos, V.A., 1989. Andean foothills structures in Northern Magallanes Basin, Argentina. American Association of Petroleum Geologists Bulletin, 73, 887-903.

Ramos, V.A, Aleman A., 2002. Tectonic evolution of the Andes. In: Cordani, U.G., Miliani, E.J., Thomaz Filho, A., Campos, D.A. (eds.). Tectonic Evolution of South America. Rio de Janeiro, 635-685.

Ramsay, J.G., Huber, M.I., 1987. The techniques of modern structural geology. Academic Press, vol. 2, 700 pp.

Rapalini, A.E., Lippai, H., Tassone, A., Cerredo, M.E., 2005. An AMS and paleomagnetic study across the Andes in Tierra del Fuego. 6 ISAG, Barcelona, España, Actas, 596-599.

Robbiano, J.A., Arbe, H., Gangui, A., 1996. Cuenca Austral Marina. In: Ramos, V.A., Turic, M.A. (eds.). Geología y Recursos Naturales de la Plataforma Continental Argentina. 13 Congreso Geológico Argentino, and 3 Congreso de Exploración de

Hidrocarburos, Buenos Aires, Relatorio, 323-342.

Smalley, R. Jr., Kendrick, E., Bevis, M.G., Dalziel, I.W.D., Taylor, F., Lautià, E., Barriga, R., Casassa, G., Olivero, E., Piana, E., 2003. Geodetic determination of relative plate motion and crustal deformation across the Scotia-South America plate boundary in eastern Tierra del Fuego. Geochemistry Geophysics Geosystem, 4, 9, 1070, doi:10.1029/2002GC000446.

Stern, C.R., De Wit, M.J., 2003. Rocas Verdes ophiolites, southernmost South America: remnants of progressive stages of development of oceanic-type crust in a continental margin back-arc basin. In: Dile, Robinson P.T. (eds.). Ophiolites in Earth History. Geological Society of London, Special Publication, 218, 665-683.

Storey, B.C., 1995. The role of mantle plumes in continental breakup: case histories from Gondwanaland. Nature, 337, 301-308.

Suárez, M., Pettigrew, T.H., 1976. An upper Mesozoic island arc-back-arc system in the southern Andes and South Georgia. Geological Magazine, 113, 305-328.

Suárez, M., Hervé, M., Puig, A., 1985. Hoja Isla Hoste e islas adyacentes. Servicio Nacional de Geologia y Mineria de Chile, 133.

Suárez, M., Hervé, F., Puig, A., 1987. Cretaceous diapiric plutonism in the southern cordillera, Chile. Geological Magazine, 124(6), 569-575.

Suárez, M., De La Cruz, R., Bell, C.M., 2000. Timing and origin of deformation along the Patagonian fold and thrust belt.

Geological Magazine, 137(4), 345-353.

Tassone, A., Lippai, H., Lodolo, E., Menichetti, M., Comba, A., Hormachea, J.L., Vilas, J.F., 2005. A geological and geophysical crustal section across the Magallanes-Fagnano fault in Tierra del Fuego. Journal of South America Earth Science, 19, 99-109.

Tassone, A., Lodolo, E., Menichetti, M., Yagupsky, D., Caffau, M., Vilas, J.F., 2008. Stratigraphic and structural setting of the Malvinas Basin and its southern margin (Tierra del Fuego Atlantic offshore), Geologica Acta 6(1), 55-57.

Waldmann, N., Ariztegui, D., Anselmetti, F.S.,, Austing Jr, J.A., Dunbar, R., Moy, C.M., Recasens, C., 2008. Seismic stratigraphy of Lago Fagnano sediments (Tierra del Fuego, Argentina) – A potential archive of paleoclimatic change and tectonic activity since the Late Glacial. Geologica Acta, 6(1), 101-110.

Williams, G.D., Vann, I., 1987. The geometry of listric normal fault and deformation in the hangingwalls. Journal of Structural Geology, 9, 789-795 .

Wilson, T.J., 1991. Transition from back-arc to foreland basin development in the southernmost Andes: Stratigraphic record from the Última Esperanza District, Chile. Geological Society of America Bulletin, 103, 98-111.

Winslow, M.A., 1982. The structural evolution of the Magallanes Basin and neotectonics in the southernmost Andes. In: Craddock, C. (ed.). Antarctic Geoscience. Madison, University of Wisconsin Press, 143-154.

Yrigoyen, M.R., 1989. Cuenca de Malvinas. In: Chebli, G., Spalletti, L. (eds.). Cuencas Sedimentarias Argentinas. Universidad Nacional de Tucumán, Serie Correlación Geológica 6, 481-491.

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2008-03-26