Abstract:
The profile from Jiujiang, Jiangxi Province to Ninghua, Fujian Province, passes through the Yangtze block and the Cathaysia block from northwest to southeast in the east of South China continent. This paper selected teleseismic records from 35 temporary broadband stations along the profile from June 2012 to June 2014 so as to obtain the crustal thickness and Poisson's ratio by the
H-
k stacking method and common conversion point (CCP) stacking method. The results show that the crustal thickness of the studied area ranges 29-33 km. The depth of Moho of the southeast edge of the Yangtze block has an obvious difference from that of the Cathaysia block. The depth of the Ping-xiang--Leping depression zone to the north of Pingxiang--Guangfeng fault exhi-bits obvious uplift of Moho in the deep, being the thinnest part of the studied area. The average value of Poisson's ratio obtained from
H-
k stacking method shows that the Poisson's ratios are as low as 0.21-0.24 beneath crust of most of the studied area. At the two sides of the Pingxiang--Guangfeng fault, the Poisson's ratio value is higher, reaching about 0.26, which means the different constitution of the rock in the deep for the disparate tectonic units. All above evidences suggest that the Pingxiang--Guangfeng fault can be considered as the extension of Jiangshan-Shaoxing coherence belt, meanwhile it is the convergent boundary of Yangtze block and Cathaysia block in the north of Jiangxi Province, therefore it is inferred that the two blocks are composed of similar material in the deep.