A thinned lithospheric image of the Tanlu Fault Zone, eastern China: Constructed from wave equation based receiver function migration

We apply the newly proposed wave equation‐based receiver function poststack migration method to the Northern China Interior Structure Project broadband data to image the lithospheric structure of the Tanlu Fault Zone area in eastern China. Our migration result reveals a 60‐ to 80‐km‐thick present‐da...

Celý popis

Uložené v:

Podrobná bibliografia
Vydané v:	Journal of Geophysical Research: Solid Earth Ročník 111; číslo B9
Hlavní autori:	Chen, Ling, Zheng, Tianyu, Xu, Weiwei
Médium:	Journal Article
Jazyk:	English
Vydavateľské údaje:	Washington, DC Blackwell Publishing Ltd 01.09.2006 American Geophysical Union
Predmet:	Earth sciences Earth, ocean, space Exact sciences and technology lithosphere-asthenosphere boundary lithospheric image lithospheric reactivation and thinning receiver function Tanlu Fault Zone wave equation migration Eastern China Far East China Northern China Mesozoic extension projects wave equation S-waves faults Modeling upwelling fault zones asthenosphere Cenozoic Thermal variation penetration lithosphere Paleozoic depth Thinning channels Asia uplifts Frequency analysis migration geometry Wave velocity Phanerozoic melts volatiles
ISSN:	0148-0227, 2156-2202
On-line prístup:	Získať plný text
Tagy:	Pridať tag Žiadne tagy, Buďte prvý, kto otaguje tento záznam!

Popis
Shrnutí:	We apply the newly proposed wave equation‐based receiver function poststack migration method to the Northern China Interior Structure Project broadband data to image the lithospheric structure of the Tanlu Fault Zone area in eastern China. Our migration result reveals a 60‐ to 80‐km‐thick present‐day lithosphere beneath the study region, significantly thinned from the Paleozoic lithosphere of >180 km. The lithosphere‐asthenosphere boundary (LAB) is coherently imaged along the ∼300‐km east‐west profile, displaying an arc‐like shape with its apex roughly coincident with the transverse location of the Tanlu Fault Zone on the surface. An obvious uplift from ∼36 km to ∼32 km of the Moho is also clearly detected right below this fault zone. The coincidence of the imaged Moho uplift and the LAB apex with the surface location of the Tanlu Fault Zone provides seismological evidence for the steep geometry and deep penetration of the fault system, and indicates that the Tanlu Fault Zone might have acted as a major channel for anthenosphere upwelling during the Mesozoic‐Cenozoic continental extension and lithospheric thinning in eastern China. Frequency analysis and synthetic modeling suggest that both the Moho and the LAB are sharp and strong. The latter, in particular, is constrained to have a 3–7% drop in S wave velocity over a depth range of 10 km or less. Such a rapid velocity change at the base of the lithosphere in the study region cannot be solely explained by thermal variation, but likely reflects the presence of volatiles or melt in the asthenosphere, or is partially attributed to the compositional contrast between the preserved depleted and dehydrated cratonic lithospheric veneer and the uplifted hydrated and fertile asthenospheric materials.
Bibliografia:	ArticleID:2005JB003974 istex:F32AA795A937A700C8AA9D171BB3FFD399FAC203 Tab-delimited Table 1. ark:/67375/WNG-M101V9LX-C
ISSN:	0148-0227 2156-2202
DOI:	10.1029/2005JB003974