LIMITED TECTONIC CONDITIONS FOR NATURAL GAS ACCUMULATION IN PALEOZOIC GROUP IN SOUTHERN HUANGHUA DEPRESSION
黄骅坳陷南区古生界天然气聚集的构造约束条件

Natural gases gathered in Paleozoic group in southern Huanghua depression, which sourced from contemporaneous coal-bearing series in marine or limnic sequences, experienced complicated migration and charging history along with tectonic evolution through Mesozoic-Cenozoic era. The accumulation process, filling mechanics and alteration of remigration pathway for reconstructing of gas pool are inevitably controlled by structural deformation during Indosinian, Yanshanian and Himalayan cycle. The thrust and strike-slip event during Indosinian and early Yanshanian are boundary conditions of hydrocarbon discharging from coal-bearing sources, and of distributing of early gas pools which formed late Mesozoic and early Cenozoic, by providing essential dynamic stress and drainage channels. Meanwhile, the fault-block rotation and reversing tectonic movement during Cenozoic era limited gas recharging style, dominated reconstruction of early gas pool. In this paper we argue that the final accumulation tapes and distribution styles of gas pools in southern Huanghua depression showed some characteristics of subtle ones, due to complex fault system and heterrosphere of reservoir in Paleozoic horizon, and most probably irrelevant to structural traps formed in later Cenozoic.