Recent geophysical surveys and basin modeling suggest that the No.1 fault in the Yinggehai basin (YGHB) is the seaward elongation of the Red River fault zone (RRFZ) in the South China Sea (SCS). The RRFZ, which separates the South China and Indochina block, extends first along the Yuedong fault, offshore of Vietnam, and then continues southward and breaks off into two branches: the Lupar fault and the Tinjia fault. The southern extension of the Lupar fault dies out beneath the NW Borneo while the Tinjia fault extends southeast and reaches the Brunei-Sabah area. According to the gravity and geomagnetic data, and the tectonic evolution of the basins, there are different evolution histories between the Wan'an basin (WAB) and the basins in the Nansha block. The Tinjia fault may be the boundary between the Balingian block and the Nansha block. Hence, the line linking the Yuedong fault and the Tinjia fault, which both are continental margin faults and strike-slip ones in the geological evolution histories, constitute the boundary between the Indochina and Nansha block. The Lupar fault, in contrast, is an intraplate fault within the Indochina block. The results provide new hints for reconstructing the tectonic evolution history of the RRFZ and the opening of the SCS, and also a framework for hydrocarbon prospecting in the region.The tectonic evolution features in the western South China Sea (SCS) are directly related to the Tethys tectonic province. The Red River fault zone (RRFZ) comprises a large part of the Tethys tectonic province and is the boundary between the Europe Block and the India-Asia Block [1] . It serves as the contact between the uplift of the Qinghai-Tibet Plateau and the SCS opening. The RRFZ, which is an important dividing line in the geology of the SE Asia, is about 1000 km long in the continent from the Qinghai-Tibet Plateau to northern Vietnam. Many workers [2][3][4][5][6][7][8][9][10][11] have looked into its petrology, geochemistry, metamorphic processes, age dating, and numerical simulation [12] and the structure of the crust and the mantle [13] . The models 840 Science in China: Series D Earth Sciencesproposed by these workers [14 -16] suggest that the RRFZ is a major fault with left-lateral strike-slip motion during the Cenozoic shifting to a right-lateral strike-slip displacement in recent time [17] . The structure feature of the RRFZ in the northwestern part of the SCS is obvious. Rangin et al. [18] calibrated the seismic stratigraphy based on the drill well data along the RRFZ and found two important unconformities. The unconformity at 30 Ma is characterized by a left-lateral strike-slip motion and another one at 5.5Ma shows no signs of post-5.5 Ma right-lateral motion. Sun et al. [19] suggested that the RRFZ was a sinistral strike-slip fault before 5 Ma and an obvious dextral strike-slip fault post 5 Ma, simulating the evolution of the Yinggehai basin (YGHB) on the basis of an analogue with thin-and thick-basal plate models. There is no doubt that the RRFZ extends all the way along the YG...

The Radon transform is a mathematical technique that has seen popular usage in seismic data processing and analysis. This paper presents a method of general Radon transform with 2‐order polynomial. We have given out the forward and inverse transform formulae and discussed how to choose the best parameters to avoid aliasing. Using some model data, we have compared the polynomial Radon with the linear Radon and parabolic Radon transforms. Furthermore, the data is focused well in the transform domain. Efficient and fast algorithms can be built up to process data having a uniform geometry. Examples using field data demonstrate clearly the robustness of the method.

Based on the acoustic wave field theory, we first study the forward model of seismic data for the case without free surface. Then we consider the case with a reflecting free surface, and derive the forward and inverse models for surface‐related multiple prediction and attenuation. In the physical insight, generation, prediction and attenuation of the wave is also deeply analyzed. The data‐consistence‐based time‐space convolution method is discussed and implemented. The method is formulated by an iterative adaptive procedure. An example with a complex bottom and complex multiple generating system is given to demonstrate its validity and stability of the method which can attenuates multiple energy effectively while keeping the primary events not damaged.

The mostly used methods for studying critical porosity and porous media are experimental measurement and analysis of testing data, and how to determine the porosity at the critical point and the constituents' properties are topics of great concern. In this article, we propose a method for calculation of these elastic parameters. Firstly, we derive three linear equations for numerical calculation. By combining regression coefficients of the equations, we propose equations for calculating constituents' parameters. Then we present the steps for calculation and give some notes. We use this method to analyze gas‐bearing sandstone samples. Using the entire densities, P‐velocities and S‐velocities as input data, we calculate related properties about porous fluid, framework and critical point. In the end, by comparing our results with test data of experimental measurements, we test our method and prove that this method is correct and effective.

No abstract