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Seismic Modeling of Lower and Mid-Crustal Structure as Exemplified by the Massiccio dei Laghi (Ivrea-Verbano Zone and Serie dei Laghi) Crustal Section, Northwestern Italy

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Abstract

An aim of seismic reflection profiling of the present-day deep continental crust is to infer the geologic structure and hence to infer the tectonic processes that led to the formation of that structure. An important test of the validity of such interpretations lies in comparison with exposed geologic sections that once lay at deep crustal levels. The Massiccio dei Laghi (Lakes Massif) of Northern Italy provides such a section, on a scale comparable with that of contemporary deep seismic profiles, yet illustrates heterogeneity on a wide range of scales. On account of its importance as providing a substantial composite cross section through continental crustal rocks, coupled with its relative accessibility in the inner arc of the Western Alps, the region has been subjected to an extraordinary degree of structural, petrological, geochemical and petrophysical study by geoscientists during the past few decades. The rocks of the region record Paleozoic accretion, metamorphic and magmatic processes, the effects of the Hercynian orogeny,post-orogenic magmatic underplating and associated lithospheric stretching and thinning, Mesozoic extension and effects associated with the position of the region in Alpine tectonism (see review by Handy et al., 1999). The assembly of the rock units probably dates from Permo-Triassic time onwards.Their relative positions in outcrop are likely close to how they that might be taken as a model for a magmatically underplated and extended crustal section. Such a section can be compared with interpretations drawn from present-day seismic reflection profiles taken from regions of extended lithosphere that have not had the misfortune(good fortune?) to be upended and exposed during a subsequent phase of collisional orogeny.

Keywords

Shear Zone Lower Crust Acoustic Impedance Seismic Section Seismic Anisotropy 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. Abousetta, A., 1991, Synthetic Seismic Sections Derived From Analogue and Numerical Models of Geological Structures, PhD thesis, University of London.Google Scholar
  2. Barboza, S. A., Bergantz, G. W., and Brown, M., 1999, Regional granulite facies metamorphism in the Ivrea zone: Is the mafic complex the smoking gun or a red herring? Geology. 27:447–450.CrossRefGoogle Scholar
  3. Barruol, G., and Kern, H., 1993, P- and S-wave velocities and shear wave splitting in the lower crustal/upper mantle transition (Ivrea zone). Experimental and calculated data, Phys. Earth Plan. Int. 95:175–194.CrossRefGoogle Scholar
  4. Barruol, G., and Mainprice, D. H., 1993, A quantitative evaluation of the contribution of crustal rocks to the shear-wave splitting of teleseismic SKS waves, Phys. Earth Plan. Int. 78:281–300.CrossRefGoogle Scholar
  5. Boriani, A., and Burlini, L., 1994, Carta Geologica della Valle Cannobina. Consiglio Nazionale delle Richerche, Milano, 1 sheet, scale. 1:25000.Google Scholar
  6. Boriani, A., Burlini, L., and Sacchi, R., 1990a, The Cossato-Mergozzo-Brissago Line and the Pogallo Line (Southern Alps, Northern Italy) and its relationships with late Hercynian magmatic and metamorphic events, Tectonophysics. 182:91–102.CrossRefGoogle Scholar
  7. Boriani, A., Origoni, E. G., Borghi, A., and Caironi, V., 1990b, The evolution of the “Serie dei Laghi” (Strona-Ceneri and Scisti dei Laghi); the upper component of the vreaVerbano crustal section; Southern Alps, North Italy and Ticino, Switzerland, Tectonophysics. 182:103–118.CrossRefGoogle Scholar
  8. Boriani, A., Origoni, E.G., and Pinarelli, L., 1995, Paleozoic evolution of the Southern Alpine crust (Northern Italy) as indicated by contrasting granitoid suites, Lithos. 35:47–63.CrossRefGoogle Scholar
  9. Boudier, F., Jackson, M., and Nicolas, A., 1984, Structural study of the Balmuccia Massif (Western Alps): A transition from mantle to lower crust, Geologie en Mijnbouw. 63:179–88.Google Scholar
  10. Brodie, K. H., and Rutter, E. H., 1987, Deep crustal extensional faulting in the Ivrea zone of Northern Italy, Tectonophysics. 140:193–12.CrossRefGoogle Scholar
  11. Burlini, L., 1994, A model for the calculation of seismic properties for geologic units. Physical properties of crustal and mantle rocks: theory and laboratory measurements, Surv. Geophys. 16:121–145.Google Scholar
  12. Burlini, L., and Fountain, D. M., 1993, Seismic anisotropy of metapelites from the Ivrea- Verbano zone and Serie dei Laghi (Northern Italy), Phys. Earth Plan. Int. 78:301–317.CrossRefGoogle Scholar
  13. Christensen, N. I., and Mooney, W. D., 1995, Seismic velocity structure and composition of the continental crust: A global view, J. Geophys. Res. 100:9761–9788.CrossRefGoogle Scholar
  14. Fountain, D. M., 1986, Implications of deep crustal evolution for seismic reflection interpretation, in: Reflection Seismology: The Continental Crust, Geodynamics Series 14 (M. Barazangi and L. Brown, eds.), American Geophysical Union, Washington, pp. 1–7.CrossRefGoogle Scholar
  15. Freeman, B., Klemperer, S. L., and Hobbs, R. W., 1988, The deep structure of Northern England and the Iapetus Suture zone from BIRPS deep seismic reflection profiles, J. Geol. Soc. London. 145:727–40.CrossRefGoogle Scholar
  16. Giese, P., Reutter, K-J., Jacobshagen, V., and Nicolich, R., 1982, Explosion seismic crustal studies in the Alpine Mediterranean region and their implications to tectonic processes, in: Alpine-Mediterranean Geodynamics, Geodynamics Series 7 (H. Berkhemer and K. J. Hsu, eds.), American Geophysical Union, Washington, pp. 39–73.CrossRefGoogle Scholar
  17. Handy, M. R., 1986, The Structure and Rheological Evolution of the Pogallo Fault Pone; Deep Crustal Dislocation in the Southern Alps of Northwestern Italy (Prov. Novara), PhD thesis, University of Basel, Basel.Google Scholar
  18. Handy, M. R., and Zingg, A., 1991, The tectonic and rheologic evolution of an attenuated cross-section of the continental crust: Ivrea crustal section, Southern Alps, Northwestern Italy and Southern Switzerland, Geol. Soc. Am. Bull. 103:236–253.CrossRefGoogle Scholar
  19. Handy, M. R., Franz, L., Heller, F., Janott, B., and Zurbriggen, R., 1999, Multistage exhumation and accretion of the continental crust (Ivrea crustal section, Italy and Switzerland), Tectonics. 18:1154–1177.CrossRefGoogle Scholar
  20. Hauser, E., Potter, C., Hauge, T., Burgess, S., Burtsch, S., Mutschler, J., Allmendinger, R., Brown, L., Kaurman, S., and Oliver, J., 1987, Crustal structure of Eastern Nevada from COCORP deep seismic reflection data, Geol. Soc. Am. Bull. 99:833–844.CrossRefGoogle Scholar
  21. Hobbs, R.W., Seismic imaging of lower crustal heterogeneity, this volume.Google Scholar
  22. Hodges, K., and Fountain, D. M., 1984, The Pogallo line, Southern Alps, Northern Italy: An intermediate crustal level, low-angle normal fault?, Geology. 12:151–155.CrossRefGoogle Scholar
  23. Henk, A., Franz, L., Teufel, S., and Oncken, 0., 1997, Magmatic underplating, extension, and crustal reequilibration: insights from a cross section through the Ivrea zone and StronaCeneri zone, Northern Italy, J. Geol. 105:367–377.CrossRefGoogle Scholar
  24. Holliger, K., and Levander, A., 1994. Structure and seismic response of extended continental crust: Stochastic analysis of the Strona-Ceneri and Ivrea zones, Geology. 22: 79–82.CrossRefGoogle Scholar
  25. Holliger, K., and Levander, A., 1994b, Seismic structure of gneissic/granitic upper crust: Geological and petrophysical evidence from the Strona-Ceneri Zone (Northern Italy) and implications for crustal seismic exploration, Geophys. J. Int. 119:497–510.CrossRefGoogle Scholar
  26. Holliger, K., Levander, A., and Goff, J. A. 1993, Stochastic modeling of the reflective lower crust: Petrophysical and geological evidence from the Ivrea zone (Northern Italy). J. Geophys. Res. 98: 11,967–11,980.CrossRefGoogle Scholar
  27. Holliger, K., Levander, A., Carbonell, R., and Hobbs, R., 1994, Some attributes of wavefields scattered from Ivrea-type lower crust, Tectonophysics. 232:267–279.CrossRefGoogle Scholar
  28. James, T., 2002, The Structure of the Contact Region Between the Ivrea-Verbano Zone and Serie dei Laghi, Massiccio dei Laghi,Northern Italy, and the Development of a GIS Database to Record Geological Information on the Region, PhD thesis, University of Manchester, Manchester.Google Scholar
  29. Kelly, K. R., Ward, R. W., Treitel, S., and Alford, R. M., 1976, Synthetic seismograms: A finite difference approach, Geophysics. 41:2–27.Google Scholar
  30. Kern, H., 1978, The effect of high temperature and high confining pressure on compressional wave velocities in quartz bearing and quartz free igneous and metamorphic rocks, Tectonophysics. 44: 185–203.CrossRefGoogle Scholar
  31. Khazanehdari, J., Rutter E. H., and Brodie, K. H., 2000, High pressure/temperature seismic velocity structure of the mid-and lower-crustal rocks of the lvrea-Verbano zone and Serie dei Laghi, NW Italy, J. Geophys. Res. 105:13,843–13,858.CrossRefGoogle Scholar
  32. Klemperer, S., and Hobbs, R., 1991, The BIRPS Atlas: Deep Seismic Reflection Profiles. Around the British Isles Cambridge University Press, Cambridge.Google Scholar
  33. Meissner, R. and Bortfeld, R. K., 1990, DEKORP-Atlas, Springer-Verlag, Berlin.Google Scholar
  34. Pin, C., 1986, Datation U-Pb sur zircons à 285 Ma du complexe gabbro-dioritique du Val Sesia-Val Mastallone étage tardi-hercynien du métamorphism granulitique de la zone Ivrea-Verbano (Italie), Comptes Rendus de l’Acadéntie des Sciences Paris. 303:827–830.Google Scholar
  35. Quick, J., Sinigoi, S., Negrini, L., Demarchi, G., and Mayer, A., 1992, Synmagmatic deformation in the underplated igneous complex of the Ivrea-Verbano zone, Geology. 20:613–616.CrossRefGoogle Scholar
  36. Quick, J., Sinigoi, S., and Mayer, A., 1994, Emplacement dynamics of a large mafic intrusion in the lower crust, Ivrea-Verbano zone, Northern Italy, J. Geophys. Res. 99:21,559–21,573.CrossRefGoogle Scholar
  37. Quick, J., Sinigoi, S., and Mayer, A., 1995, Emplacement of mantle peridotite in the lower continental crust, Ivrea-Verbano zone, Northern Italy, Geology. 23:739–742.CrossRefGoogle Scholar
  38. Ramsay, J. G. 1967, Folding and Fracturing of Rocks, McGraw Hill, New York.Google Scholar
  39. Reston, T. J., 1987, Spatial interference, reflection character and the structure of the lower crust under extension. Results from 2-D seismic modelling, Anna/es Geophysicae. 5:339–348.Google Scholar
  40. Rivalenti, G., Garuti, G., Rossi, A., Siena, F., and Sinigoi, S., 1981, Existence of different peridotite types and of a layered igneous complex in the Ivrea zone of the western Alps, J. Petr. 22:127–153.Google Scholar
  41. Rumpker, G., and Silver, P. G., 1998, Apparent shear-wave splitting parameters in the presence of vertically varying anisotropy, Geophys. J. Int. 135:790–800.CrossRefGoogle Scholar
  42. Rutter, E. H., Brodie, K. H., and Evans, P., 1993, Structural geometry, lower crustal magmatic underplating and lithospheric stretching in the Ivrea-Verbano zone, Northern Italy, J. Struct. Geol. 15:647–662.CrossRefGoogle Scholar
  43. Rutter, E. H., Khazanehdari, J., Brodie, K. H., Blundell, D., and Waltham, D., 1999, Synthetic seismic reflection profile through the Ivrea-Verbano zone - Serie dei Laghi continental crustal section, Northwestern Italy, Geology. 27:79–82.CrossRefGoogle Scholar
  44. Salter, R. L., Gahert, J., and Jordan, T. H., 2000, How are vertical shear wave splitting measurements affected by variations in the orientation of azimuthal anisotropy at depth?, Geophys. J. Int. 141:374–390.CrossRefGoogle Scholar
  45. Schmid, R., 1967, Zur Petrographie und Strukur der Zone Ivrea-Verbano zwischen Valle d’Ossola und Val Grande (Provinz Novara, Italien), Schweiz. Min. Petr. Mitt. 47:935–1117.Google Scholar
  46. Schmid, R., and Wood, B. J., 1976, Phase relationships in granulite metapelites from the lvrea-Verbano zone (Northern Italy), Cont. Miner. Petr. 54:255–279.CrossRefGoogle Scholar
  47. Schmid, S. M., Zingg, A.. and Handy, M. R., 1987, The kinematics of movements along the lnsubric Line and the emplacement of the Ivrea zone, J. Struct. Geol. 135:47–66.Google Scholar
  48. Sills, J. D., and Tarney, I., 1984, Petrogenesis and tectonic significance of amphibolites interlayered with metasedimentary gneisses in the Ivrea zone, Southern Alps. Northern Italy, Tectonophysics. 107:187–206.CrossRefGoogle Scholar
  49. Sinigoi, S., Antonini, P., Demarchi, G., Longinelli, A., Mazzuchelli, M., Negrini, L., and Rivalenti, G., 1991, Interactions of mantle and crustal magmas in the southern part of the Ivrea zone (Italy), Cont. Miner. Petr. 108:385–395.CrossRefGoogle Scholar
  50. Snoke, A.W., Kalakay, T. J., Quick, J. E., and Sinigoi, S., 1999, Development of a deep crustal shear zone in response to tectonic intrusion of mafic magma into the lower crust, Ivrea-Verbano zone, Italy, Earth Plan. Sci. Lett. 166:31–45.CrossRefGoogle Scholar
  51. Vogler, R., 1992, Die Ivrea Zone zwischen Val Grande and Val Pogallo (Provinz Novara, Italien), Schweiz. Min. Petr. Mitt. 72:241–249.Google Scholar
  52. Yardley, B. W. D., 1986, Is there water in the deep continental crust?, Nature. 323:111.CrossRefGoogle Scholar
  53. Zingg, A., 1980, Regional metamorphism of the Ivrea zone (Southern Alps, Northern Italy): Field and microscopic investigations, Schweiz. Min. Petr. Mitt. 60:153–179.Google Scholar
  54. Zingg, A., 1983, The Ivrea and Strona-Ceneri zones (Southern Alps, Ticino and Northern Italy) - A review, Schweiz. Min. Petr. Mitt. 63:361–392.Google Scholar
  55. Zingg, A., Handy, M. R., Hunziker, J. C., and Schmid, S. M., 1990, Tectonometamorphic history of the Ivrea zone and its relationship to the crustal evolution of the Southern Alps, Tectonophysics. 182:169–192.CrossRefGoogle Scholar
  56. Zurbriggen, R., Franz, L., and Handy, M. R., 1997, Pre-Variscan deformation, metamorphism and magmatism in the Strona-Ceneri zone (Southern Alps of Northern Italy and Southern Switzerland), Schweiz. Min. Petr. Mitt. 77:361–380.Google Scholar
  57. Zurbriggen, R., Kamber, B. S., Handy, M. R., and Nagler, T. F., 1998, Dating synmagmatic folds: a case study of schlingen structures in the Strona-Ceneri zone (Southern Alps, Northern Italy), J. Metatn. Geol. 16:403–414.CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 2003

Authors and Affiliations

  1. 1.Rock Deformation Laboratory, Department of Earth SciencesUniversity of ManchesterManchesterUK
  2. 2.Geology DepartmentRoyal Holloway College, University of LondonEgham, SurreyUK

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