Lithospheric structure of the Chaco and Paraná Basins of South America from surface-wave inversion

作者: J. Arthur Snoke , David E. James

DOI: 10.1029/96JB03180

关键词:

摘要: Surface-wave data from a portable broadband array have been used to invert for the velocity structure of crust and upper mantle beneath Chaco Parana Basins central South America. The upper-mantle Basin is cratonic in character, whereas that tectonic or asthenospheric character. surface-wave analysis recordings subset 14-station deployed roughly east-west sawtooth arrangement along 20°S latitude, with total E-W aperture ∼1,400 km. Results receiver-function analysis, as well direct P-wave regional travel-time data, were inversions help constrain Moho depths velocities. S-wave intracratonic was determined using interstation phase group velocities Rayleigh waves (fundamental first higher mode) Love mode only) based on seven events paths which traverse eastern one event path across western Basin. average depth ∼42 high-velocity lid has maximum 4.7 km/s, no resolvable low-velocity zone at least 200 km depth. This indicates presence lithospheric root despite emplacement plume. limited are consistent homogeneous throughout Waveform inversion fundamental-mode first-higher-mode single subandean obtain estimates pure-path dispersion propagation through half partitioned isolate partial-path contribution this somewhat sparse set inverted velocity-depth model distinguishing features consist rather shallow depth, 32 km, low (“asthenospheric”) velocities, about 4.2 increasing only slightly 4.3km/s 150

参考文章(22)
Guust Nolet, Linearized Inversion of (Teleseismic) Data Springer, Boston, MA. pp. 9- 37 ,(1981) , 10.1007/978-1-4684-3962-5_2
Luis Carlos Ribotta, Arthur Snoke, David E James, Marcelo Assumpcao, Randy Kuehnel, Seismic studies of continental lithosphere beneath SE Brazil Anais Da Academia Brasileira De Ciencias. ,vol. 65, pp. 227- 250 ,(1993)
S. Bloch, M. Landisman, A. Dziewonski, A technique for the analysis of transient seismic signals Bulletin of the Seismological Society of America. ,vol. 59, pp. 427- 444 ,(1969)
A H. F. Robertson, Probing continental collision in the Mediterranean Sea Eos, Transactions American Geophysical Union. ,vol. 75, pp. 233- 239 ,(1994) , 10.1029/94EO00909
Benjamin Bley de Brito Neves, Umberto G. Cordani, Tectonic evolution of South America during the Late Proterozoic Precambrian Research. ,vol. 53, pp. 23- 40 ,(1991) , 10.1016/0301-9268(91)90004-T
P. Wessel, W. H. F. Smith, Free software helps map and display data Eos, Transactions American Geophysical Union. ,vol. 72, pp. 441- 446 ,(1991) , 10.1029/90EO00319
John C. VanDecar, David E. James, Marcelo Assumpção, Seismic evidence for a fossil mantle plume beneath South America and implications for plate driving forces Nature. ,vol. 378, pp. 25- 31 ,(1995) , 10.1038/378025A0
Thierry Sempere, Gérard Hérail, Jaime Oller, Michel G. Bonhomme, Late Oligocene-early Miocene major tectonic crisis and related basins in Bolivia Geology. ,vol. 18, pp. 946- 949 ,(1990) , 10.1130/0091-7613(1990)018<0946:LOEMMT>2.3.CO;2
Steven G. Henry, Henry N. Pollack, Terrestrial heat flow above the Andean Subduction Zone in Bolivia and Peru Journal of Geophysical Research: Solid Earth. ,vol. 93, pp. 15153- 15162 ,(1988) , 10.1029/JB093IB12P15153