Abstract: During the halfgraben lacustrine basin developed, the episodic differential subsidence controlled by the main fault in steep slope zone of the lacustrine basin will result in the accommodation redistributed. While the water redistributing, the change of the relative lake level is not even at each point in lacustrine basin and the parasequence sets are also different. The concept of the accommodation transform hinge of half-graben lacustrine basin is put forward. The mathematic model of the accommodation transform hinge is built theoretically. The distributing position of the accommodation transform hinge and the influence factors are discussed. If it is located under the accommodation transform hinge in the gentle slope zone, the depth of water becomes deeper and forms TST(transgressive system tract); on the contrary, the water becomes shallow and forms RST(regressive system tract). HST(highstand system tract) will be formed in the tranquility period. The conception can help researchers study the uneven change of the relative lake level in half-graben lacustrine, and it is also helpful to find subtle reservoirs.

Key words: half-graben lacustrine basin, episodic differential subsidence, accommodation transform hinge, parasequence set

摘要： 单断断陷湖盆发育过程中，由主断层控制的幕式差异沉降活动将导致可容空间重新分配。水体发生重新分配过程中，湖盆中各点的相对湖平面变化并不统一，由此产生的准层序组也不一致。本文提出了断陷湖盆中可容空间转化枢纽的概念，建立了可容空间转化枢纽的数学计算模型，讨论了可容空间转化枢纽的分布位置，以及对其存在的各种影响因素。位于缓坡带可容空间转化枢纽下部，相对水体深度变深，形成退积型准层序组；反之，则变浅，形成进积型准层序组；稳定期形成加积型准层序组。可容空间转化枢纽的提出，对于定量认识单断湖盆相对湖平面不均一变化，以及对于隐蔽性油气藏的勘探都有一定的参考意义。

关键词: 单断湖盆, 幕式活动, 可容空间转化枢纽, 准层序组