太湖湖区多处岛屿和半岛的晚泥盆世石英砂岩中发现造型奇特的尖劈形张性微裂隙.微裂隙呈“人”字形组合,成单列或多列产出.一些“人”字形微裂隙的锐角区内侧的石英晶体已强烈非晶质化,具有击变玻璃的特征.研究表明这种特殊的微裂隙是冲击变质作用压力达到峰压后在卸载过程中产生的. In the late Devonian quartz sandstone of many islands and peninsulas of the Taihu Lake area, peculiar spiked zigzag microfacies were found, and the microfractures were presented as single or multiple columns with “human” Quartz crystals inside the acute angle region have been strongly amorphous and have the characteristics of glass strain. Research shows that this special microcrack is produced during the unloading process after the impact metamorphism has reached the peak pressure.