A new limit for the NW Río de la Plata Craton Border at about 24ºS (Argentina) detected by Magnetotellurics
DOI:
https://doi.org/10.1344/GeologicaActa2015.13.3.6Keywords:
Magnetotelluric, Río de Plata Craton, North Argentina, FormosaAbstract
Old South American structures constitute a puzzle where the Río de la Plata Craton is the most important clue in the assembly of SW Gondwana. The present study is aimed at characterizing the western border of the Río de la Plata Craton on the basis of magnetotelluric studies. Magnetotelluric (MT) data were acquired along an approximately NW-SE 750km profile at about 24ºS, from the Sub-Andean Ranges in the province of Salta (NW) to the Formosa Province frontier (SE) next to Paraguay River. Distortion and structure dimensionality analysis indicates that MT responses are two-dimensional with a NS strike orientation, consistent with the regional geological strike. A 2-D inversion of the data provided a model showing a lateral discontinuity, possibly associated with cratonic structures. The high resistivity observed (>5000ohm·m), from about the middle of the profile toward its eastern end, may be interpreted as the terranes accreted to the Río de la Plata Craton during Neoproterozoic to Cambrian times, or as the Río de la Plata Craton itself. Along the profile from the surface to a depth of about 10km the resistivity model shows a significant resistivity variation in the structure. The resistive block identified at the western end of the profile represents the Sub-Andean system. The markedly enhanced low-resistivity structure (~1 to 10ohm·m) corresponds to a sedimentary pile whose thickness decreases from NW to SE.
References
Alkmim, F.F., Marshak, S., Fonseca, M.A., 2001. Assembling West Gondwana in the Neoproterozoic: clues from the São Francisco craton region, Brazil. Geology, 29(4), 319-322.
Assumpção, M., Feng, M., Tassara, A., Julià, J., 2013. Models of Crustal Thickness for South America from Seismic Refraction, Receiver Functions and Surface Wave Tomography. Tectonophysics, 609, 82-96.
Bahr, K., 1988. Interpretation of the magnetotelluric impedance tensor: regional induction and local telluric distortion. Journal of Geophysics, 62, 119-127.
Bahr, K., 1991. Geological noise in magnetotelluric data: a classification of distortion types. Physics of the Earth and Planetary Interiors, 66(1-2), 24-38.
Bibby, H.M., Caldwell, T.G., Brown, C., 2005. Determinable and non-determinable parameters of galvanic distortion in magnetotellurics. Geophysical Journal International, 163, 915-930.
Bologna, M.S., Nunes, H.O., Padilha, A.L., Vitorello, Í., Pádua, M.B., 2013. Anomalous electrical structure in the northwestern Paraná Basin, Brazil, observed with broadband magnetotellurics. Journal South American Earth Science, 42, 74-82.
Booker, J., Favetto, A., Pomposiello, C., 2004. Low electrical resistivity associated with plunging of the Nazca flat slab beneath Argentina. Nature, 429, 399-403.
Brito Neves, B.B., Campos Neto, M.C. Fuck, R.A., 1999. From Rodinia to Western Gondwana: an approach to the BrasilianoPan African cycle and orogenic collage. Episodes, 22, 155-166.
Burd, A., Booker, J., Mackie, R, Pomposiello, C., Favetto, A., 2013. Electrical Conductivity of the Pampean shallow subduction region of Argentina near 33ºS: Evidence for a slab window. Geochemistry, Geophysics, Geosystems, 14(8), 3192-3209.
Chave, A.D., Smith, T., 1994. On electric and magnetic galvanic distortion tensor decompositions. Journal of Geophysical Research, 99, 4669-4682.
Caldwell, T.G., Bibby, H.M., Brown, C., 2004. The magnetotelluric phase tensor. Geophysical Journal International, 158, 457-469.
Chernicoff, C.J., Zappettini, E.O., 2004. Geophysical evidence for terrane boundaries in south-central Argentina. Gondwana Research, 7, 1105-1116.
Cordani, U.G., Brito-Neves, B.B., D’Agrella-Filho, M.S., 2001. From Rodinia to Gondwana: a review of the available evidence from South America. Gondwana Research, 4, 600-602.
Cordani, U.G., D’Agrella-Filho, M.S., Brito-Neves, B.B., Trindade, R.I.F., 2003. Tearing up Rodinia: the Neoproterozoic palaeogeography of South American cratonic fragments. Terra Nova, 15(5), 350-359.
Egbert, G.D., 1997. Robust multiple-station magnetotelluric data processing. Geophysical Journal International, 130, 475-496.
Evans, R., Jones, A., Muller, M., Hamilton, M., Evans, S., Fourie, C., Spratt, J., Webb, S., Jelsma, H., Hutchins, D., 2011. Electrical lithosphere beneath the Kaapvaal craton, southern Africa. Journal of Geophysical Research: Solid Earth, 116 B04105, 16pp.
Favetto, A., Pomposiello, C., López de Luchi, M. , Booker, J., 2008. 2D magnetotelluric interpretation of the crust electrical resistivity across the Pampean terrane-Río de la Plata suture, in central Argentina. Tectonophysics, 459, 54-65.
Favetto, A., Rocha V., Pomposiello, C., García, R., Curcio, A., 2010. Geologic features of the main crustal structures at the Chaco-Pampean Plain, Formosa Province in NW Argentina from Magnetotellurics. Electromagnetic Induction in the Earth 20th Workshop Abstract, Giza, Egypt, September 18-24, 2010.
Feng, M., Assumpção, M., Van der Lee, S., 2004. Group-velocity tomography and lithospheric S-velocity structure of the South American continent. Physics of the Earth and Planetary Interiors, 147, 315-331.
Fischel, D.P., Pimentel, M.M., Fuck, R.A., Armstrong, R., 2001. U–Pb SHRIMP and Sm–Nd geochronology of the Silvânia Volcanics and Jurubatuba Granite: juvenile Paleoproterozoic crust in the basement of the Neoproterozoic Brasília Belt, Goiás, central Brazil. Anais da Academia Brasileira de Ciências, 73, 445-460.
García, R. F., Rocha Fasola V., Moya Ruiz F. A., Tálamo, E., García Ortiz, M., Favetto, A., Pomposiello, C, J. Vargas Yegros, 2008. Hidrología Subterránea Profunda de la Provincia de Formosa. República Argentina. Modelo Geoeléctrico–Magnetotelúrico. IX Congreso ALHSUD, Quito. Ecuador.
Groom, R.W., Bailey, R.C., 1989. Decomposition of magnetotelluric impedance tensor in the presence of local three-dimensional galvanic distortion. Journal of Geophysical Research, 94, 1913-1925.
Groom, R.W., Kurtz, R.D., Jones, A.G., Boerner, D.E., 1993. A quantitative methodology to extract regional magnetotelluric impedances and determine the dimension of conductive structure. Geophysical Journal International, 115(3), 1095-1118.
Jones, A.G., Lezaeta, P., Ferguson, I.J., Chave, A.D., Evans, R.L., Garcia, X., Spratt, J., 2003. The electrical structure of the Slave craton. Lithos, 71, 505-527
Kröner, A., Cordani, U.G., 2003. African, southern Indian and South American cratons were not part of the Rodinia supercontinent: evidence from field relationships and geochronology. Tectonophysics, 375(1-4), 325-352.
McNeice, G.W., Jones, A.G., 2001. Multisite, multifrequency tensor decomposition of magnetotelluric data. Geophysics, 66, 158-173.
Murphy, J.B., Pisarevsky, S.A., Nance, R.D., Keppie, J.D., 2004. Neoprotero-zoic–Early Paleozoic evolution of peri-Gondwanan terranes: implications for Laurentia–Gondwana connections.
International Journal of Earth Sciences, 93, 659-682. Orozco, L.A., Favetto, A., Pomposiello, C., Rossello, E. Booker, J., 2013. Crustal deformation of the Andean foreland at 31°30’S (Argentina) constrained by magnetotelluric survey. Tectonophysics, 582, 126-139.
Oyhantçabal, P., Siegesmund, S., Wemmer, K., 2010. The Río de la Plata Craton: a review of units, boundaries, ages and isotopic signature. International Journal of Earth Science, 100, 201-220.
Pankhurst, R.J., Weaver, S.D., Bradshaw, J.D., Storey, B.C., Ireland, T.R., 1998. Geochronology and geochemistry of pre-Jurassic superterranes in Marie Byrd Land, Antarctica. Journal of Geophysical Research, 103, 2529-2547.
Peri, V.G., Pomposiello, M.C., Favetto, A., Barcelona, H., Rossello, E., 2013. Magnetotelluric evidence of the tectonic boundary between the Río de La Plata Craton and the Pampean Terrane (Chaco-Pampean Plain, Argentina): the extension of the Transbrasilian Lineament. Tectonophysics, 608, 685-699.
Peri, V.G., Barcelona, H., Pomposiello, M.C., Favetto, A., 2015. Magnetotelluric characterization through the AmbargastaSumampa Range: The connection between the northern and southern trace of the Río de La Plata Craton-Pampean Terrane tectonic boundary. Tectonophysics, 59, 1-12.
Ramé, G.A., Miró, R.C., 2011. Modelo geofísico de contacto entre el Orógeno Pampeano y el Cratón del Río de La Plata en las provincias de Córdoba y Santiago del Estero. Serie Correlación Geológica 27(2), 111-123.
Ramos, V.A., Vujovich, G., Martino, R., Otamendi, J., 2010. Pampia: A large cratonic block missing in the Rodinia supercontinent. Journal of Geodynamics, 50, 243-255.
Rapalini, A.E., 2005. The accretionary history of southern South America from the latest Proterozoic to the late Paleozoic: some paleomagnetic constraints. Geological Society, London
(Special Publication) 246, 305-328.
Rapela, C.W., Pankhurst, R.J., Casquet, C., Fanning, C.M., Baldo, E.G., González-Casado, J.M., Galindo, C., Dahlquist, J., 2007. The Río de la Plata craton and the assembly of SW Gondwana. Earth Science Reviews, 83(1-2), 49-82.
Rapela, C.W., Fanning, C.M., Casquet, C., Pankhurst, R.J., Spalletti, L., Poiré, D., Baldo, E.G., 2011. The Río de la Plata craton and the adjoining Pan-African/brasiliano terranes: Their origins and incorporation into south-west Gondwana. Gondwana Research, 20, 673-690.
Rodi, W., Mackie, R.L., 2001. Nonlinear conjugate gradients algorithm for 2D magnetotelluric inversion. Geophysics, 66(1), 174-187.
Russo, A., Ferrelo, R., Chebli, G., 1979. Llanura Chaco Pampeana. Segundo Simposio de Geología Regional Argentina. Academia Nacional de Ciencias. Volumen I. Córdoba.
Smith. J.T., 1995. Understanding telluric distortion matrices. Geophysical Journal International, 122, 219-226.
Tassara, A., Echaurren, A., 2012. Anatomy of the Andean subduction zone: three dimensional density model upgraded and compared against global-scale models. Geophysical Journal International, 189(1), 161-168.
Tassara, A., Götze, H.-J., Schmidt, S., Hackney, R., 2006. Threedimensional density model of the Nazca plate and the Andean continental margin. Journal of Geophysical Research, 111, B09404.
Tohver, E., D’Agrella-Filho, M.S., Trindade, R.I.F., 2006. Paleomagnetic record of Africa and South America for the 1200–500Ma interval and evaluation of Rodinia and Gondwana assemblies. Precambrian Research, 147(3), 193-222.
Trindade, R.I.F., D’Agrella-Filho, M.S., Epof, I., Brito-Neves, B.B., 2006. Paleomagnetism of the early Cambrian Itabaiana mafic dikes, NE Brazil, and implications for the final assembly of Gondwana and its proximity to Laurentia. Earth and Planetary Science Letters, 244, 361-377.
Unrug, R., 1997. Rodinia to Gondwana: the geodynamic map of Gondwana supercontinent assembly. GSA Today, 7, 1-6.
Vaughan, A.P.M., Storey, B.C., 2000. The eastern Palmer Land shear zone: a new terrane accretion model for the Mesozoic development of the Antarctic Peninsula. Journal of the Geological Society (London), 157, 1243-1256.
Downloads
Published
Issue
Section
License
![Creative Commons License](http://i.creativecommons.org/l/by-sa/4.0/88x31.png)
This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.
Copyright
Geologica Acta is the property of the UB, GEO3BCN, IDAEA and UAB. Geologica Acta must be cited for any partial or full reproduction. Papers are distributed under the Attribution-Share Alike Creative Commons License. This license allows anyone to reproduce and disseminate the content of the journal and even make derivative works crediting authorship and provenance and distributing possible derivative works under the same or an equivalent license.
Author Rights
Authors retain the copyright on their papers and are authorized to post them on their own web pages or institutional repositories. The copyright was retained by the journal from the year 2003 until 2009. In all cases, the complete citation and a link to the Digital Object Identifier (DOI) of the article must be included.
The authors can use excerpts or reproduce illustrations of their papers in other works without prior permission from Geologica Acta provided the source of the paper including the complete citation is fully acknowledged.