构造三角带的概念及其油气勘探意义

构造三角带通常发育于褶皱冲断带中，是油气勘探的重要目标。构造三角带具有多种几何形态和命名，其中，阿尔伯达型构造三角带具有普遍意义。近年来，国内外对构造三角带的研究工作取得了重要进展。利用物理模拟和数值模拟并结合实际地质情况，许多学者对构造三角带的演化提出了多种运动学模型和成因解释，本文介绍了2个运动学模型和单斜推进模式。影响构造三角带形成与发展的因素包括滑脱层、地层能干性差异、同构造沉积、剥蚀等。由于其内部构造的复杂性，三角带的地震剖面品质一般较差。而利用地震模拟和生长地层的方法可以在地震剖面上帮助识别出构造三角带。国内的地震勘探表明，中国西部挤压盆地中广泛发育三角带构造。文中列举了中国西部盆地中发育的构造三角带的实例。

The definition of triangle zone and its petroleum prospecting significance.

Triangle zones normally develop in foreland fold-and-thrust belts and become favorable object of petroleum exploration. The geometry and nomenclature of triangle zones vary from place to place, among which Alberta-style triangle zone is of common significance. Progresses have been made on triangle zones in that a large number of work have been done at home and abroad in recent years. Based on physical and numerical modeling and integration of geological data, different kinematic and genetic models have been proposed, in which two kinematic models and a genetic model, prograding monocline model, are presented in this paper. Factors influencing the formation and development of triangle zones include décollement, variation of mechanical stratigraphy, syntectonic sedimentation, erosion and so on. Owing to their complexity in structure, triangle zones commonly have poor quality on seismic profiles. Consequently, seismic modeling and strata-in-growth method can be used to identify triangle zones. Seismic explorations demonstrate that triangle zones are widely distributed in zones around the basins in western China, and several examples are shown in this paper.