Crustal thickness and V P/V S variations in the Grenville orogen (Ontario, Canada) from analysis of teleseismic receiver functions
2006 (engelsk)Inngår i: Tectonophysics, ISSN 0040-1951, E-ISSN 1879-3266, Vol. 420, nr 1-2, s. 223-238Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]
We have developed a simple semblance-weighted stacking technique to estimate crustal thickness and average V P/V S ratio using teleseismic receiver functions. We have applied our method to data from 32 broadband seismograph stations that cover a 700 × 400 km 2 region of the Grenville orogen, a 1.2-0.98 Ga Himalayan-scale collisional belt in eastern North America. Our seismograph network partly overlaps with Lithoprobe and other crustal refraction surveys. In 8 out of 9 cases where a crustal-refraction profile passes within 30 km of a seismograph station, the two independent crustal thickness estimates agree to within 7%. Our regional crustal-thickness model, constructed using both teleseismic and refraction observations, ranges between 34.0 and 52.4 km. Crustal-thickness trends show a strong correlation with geological belts, but do not correlate with surface topography and are far in excess of relief required to maintain local isostatic equilibrium. The thickest crust (52.4 ± 1.7 km) was found at a station located within the 1.1 Ga mid-continent (failed) rift. The Central Gneiss Belt, which contains rocks exhumed from deep levels of the crust, is characterized by V P/V S ranging from 1.78 to 1.85. In other parts of the Grenville orogen, V P/V S is found to be generally less than 1.80. The thinnest crust (34.5-37.0 km) occurs northeast of the 0.7 Ga Ottawa-Bonnechere graben and correlates with areas of high intraplate seismicity
sted, utgiver, år, opplag, sider
2006. Vol. 420, nr 1-2, s. 223-238
Identifikatorer
URN: urn:nbn:se:ltu:diva-11640DOI: 10.1016/j.tecto.2006.01.023ISI: 000238792100015Scopus ID: 2-s2.0-33744969376Lokal ID: aa78308c-a1e5-454d-b2b0-2a47555a4ff9OAI: oai:DiVA.org:ltu-11640DiVA, id: diva2:984590
Merknad
Upprättat; 2012; 20120924 (andbra)
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