辽西义县地区黄花山角砾岩研究的新进展

New Progress in the Study of Huanghuashan Breccia in Yixian County, Western Liaoning

对辽西地区黄花山角砾岩层的研究表明 ,黄花山角砾岩是一套火山碎屑岩 火山碎屑沉积岩类。黄花山角砾岩的形成大致可分为 2个阶段 :早期阶段以火山熔岩溢流和剧烈的火山爆发作用为主 ,不同地区形成了火山角砾岩 (火山碎屑岩 )或火山熔岩 ;晚期阶段 ,黄花山角砾岩成层性较好 ,以厚 中层为主 ,并且向上部韵律逐渐发育 ,表明这个时期渐变为以沉积作用为主 ,形成了火山碎屑沉积岩。黄花山角砾岩层和义县晚期的酸性火山熔岩同是义县组的顶部层位 ,二者为同时异相关系(但不是过渡关系 )。黄花山角砾岩层的定位对正确认识义县组以及研究阜新 义县盆地的演化史有着重要意义。

Based on a detailed study of the Huanghuashan breccia layer, it is known that the Huanghuashan breccia is a kind of pyroclastic rock-pyroclastic sedimentary rock. The formation of the breccia layer can be divided into two periods. The early period is a period of lava overflow and violent volcanic eruption, which formed mainly pyroclastic rock or lava. The late period (the upper layer) is characterized by better stratification in Huanghuashan breccia, great to intermediate thickness, and gradual development of rhythm in upward direction, suggesting that the period was dominated by sedimentary activity and formed pyroclastic sedimentary rock. Both the Huanghuashan breccia layer and the acid volcanic rock in late Yixian period are the upper horizon of Yixian Formation, belonging to different facies of the same period. The locating of Huanghuashan breccia is of great significance in the study of Yixan Formation and Fuxin-Yixian basin in western Liaoning.