鄂北大洪山地区“花山群”的解体

DISINTEGRATION OF THE HUASHAN GROUP IN THE DAHONG MOUNTAIN AREA, NORTHERN HUBEI

岩性—构造填图结果表明，大洪山区的原“花山群”实际上包含３套不同时代、不同环境的物质建造，应予以解体。其中襄广断裂带内分布的以基性火山岩为主的一套岩系是构造侵位的蛇绿混杂岩，称之为花山蛇绿混杂岩；大洪山以西的耿集—板桥火山—沉积岩系，是南秦岭随县群的构造岩块；剔除这两者之后的碎屑沉积岩系定为真正意义的花山群，沉积时代为晚元古代。

Lithologic tectonic mapping indicates that the original 'Huashan Group' should be disintegrated into three parts which are of different ages and were formed in different tectonic settings. The first one is the Huashan ophiolitic mélange composed mainly of basic volcanic rocks and emplaced tectonically into the Xiangguang fault northeast of Dahong Mountain. The second is the volcanic sedimentary series in the Gengji Banqiao area west of Dahong Mountain, which is a tectonic block of the Suixian Group in the South Qinling belt. The third is the newly defined Huashan Group, which consists mainly of conglomerates, sandstones, mudstones and slates deposited in the Late Proterozoic.