Crustal and lithospheric structure of inactive volcanic arc terrains in Fiji

Chen, Jie1; Chen, Yongshun John1,2; Wiens, Douglas A.3; Wei, S. Shawn4; Zha, Yang5; Julia, Jordi6,7; Cai, Chen3

2019-01-05

10.1016/j.tecto.2018.07.014

TECTONOPHYSICS   影响因子和分区

0040-1951

1879-3266

The crustal and lithospheric velocity structure of the Fiji area may place important constraints on the evolution of island arcs in the region. Here, we obtain receiver functions from one permanent seismic station and three temporary networks on the Fiji Platform, the Lau Ridge, and other small islands to develop point estimates of crustal thickness under the networks. We obtain preliminary estimates of crustal thickness and Poisson's ratio from H-kappa stacking of the receiver functions. We then perform an inversion for shear-wave velocity structure using a joint inversion of receiver functions and Rayleigh wave dispersion curves from ambient seismic noise and teleseismic events. The joint inversion results show an average crustal thickness of similar to 30 km beneath Viti Levu, the largest Fiji island, suggesting an extensive period of arc crustal formation and thickening. In contrast, we find shallower Moho depths averaging similar to 22 km beneath the smaller Fiji islands and the Lau Ridge. The limited thickness of the high velocity lid obtained by inversion indicates that the lithosphere is thinned beneath the marginal Fiji islands, which may be due to the early rifting event forming the Lau Basin together with the crustal thinning of this area as well, and to thermal lithospheric erosion processes associated with adjacent back-arc spreading. A relatively slow velocity middle crustal layer, roughly of 11-16 km thickness, exists throughout Fiji, suggesting that remnant arcs contain significant volumes of felsic crustal rocks necessary for continental crust formation.

Receiver function Joint inversion Fiji arc Crustal thickness Lithospheric structure

SCI ; EI

英语

通讯

NSF[OCE-0426408] ; NSF[EAR-0911137]

Geochemistry & Geophysics

Geochemistry & Geophysics

WOS:000458713300025

ELSEVIER SCIENCE BV

20185206296825

Dispersion (waves) ; Seismology ; Shear flow ; Shear waves ; Velocity ; Wave propagation

Geology:481.1 ; Earthquake Measurements and Analysis:484.1 ; Fluid Flow, General:631.1 ; Mechanics:931.1

GEOSCIENCES

Web of Science

1.Peking Univ, Sch Earth & Space Sci, Inst Theoret & Appl Geophys, Beijing, Peoples R China
2.Southern Univ Sci & Technol, Dept Ocean Sci & Engn, Shenzhen, Peoples R China
3.Washington Univ, Dept Earth & Planetary Sci, St Louis, MO 63130 USA
4.Michigan State Univ, Dept Earth & Environm Sci, E Lansing, MI 48824 USA
5.Conoco Phillips, Houston, TX USA
6.Univ Fed Rio Grande do Norte, Pasgrad Geodinam & Geofis, Natal, RN, Brazil
7.Univ Fed Rio Grande do Norte, Dept Geofis, Natal, RN, Brazil

Chen, Jie,Chen, Yongshun John,Wiens, Douglas A.,et al. Crustal and lithospheric structure of inactive volcanic arc terrains in Fiji[J]. TECTONOPHYSICS,2019,750:394-403.

Chen, Jie.,Chen, Yongshun John.,Wiens, Douglas A..,Wei, S. Shawn.,Zha, Yang.,...&Cai, Chen.(2019).Crustal and lithospheric structure of inactive volcanic arc terrains in Fiji.TECTONOPHYSICS,750,394-403.

Chen, Jie,et al."Crustal and lithospheric structure of inactive volcanic arc terrains in Fiji".TECTONOPHYSICS 750(2019):394-403.