鄂东南地区南华系沉积特征与接触关系:扬子陆块内部与东南缘盆地对比的良好借鉴

STRATIGRAPHIC SEQUENCE AND CONTACT RELATIONSHIP OF THE NANHUA SYSTEM IN SOUTH-EASTERN HUBEI PROVINCE:A KEY TO THE STRATIGRAPHIC CORRELATION BETWEEN THE INNER YANGTZE REGION AND THE SOUTH-EASTERN BASIN

鄂东南处于扬子地层区下扬子地层分区与江南地层分区交界处,南华系发育齐全,莲沱组由砾岩、砂岩、凝灰岩组成,岩性组合与扬子陆块内部可以很好的进行对比,而其与下伏地层假整合接触,与东南缘盆地相同;鄂东南的古城组、大塘坡组、南沱组表现出兼具扬子陆块内部及东南缘盆地的沉积特征;在接触关系上,各组间为整合接触,与东南缘盆地沉积特征相同。扬子陆块内部与东南缘盆地南华系对比仍存在分歧,鄂东南处于扬子陆块内部与东南缘盆地的过渡地带,为不同相区南华系对比建立了很好的桥梁。通过进一步工作,有望确定莲沱组、古城组等关键层位的对比等问题。

Stratigraphic correlation of the Nanhua System remains controversial. Southeastern Hubei Prov- ince is located at the boundary between the Lower Yangtze and Jiangnan sub-regions in the Yangtze block with a complete succession of the Nanhua System. In this area, the Liantuo Formation consists of con- glomerate, sandstone and tuff, which can be correlated with that of the Inner Yangtze sub-region. As in the South-Eastern Basin, the Liantuo Formation unconformably overlies underlying strata. The Gucheng, Datangpo, and Nantuo formations share characteristics of the inner Yangtze region and the South-eastern basin. These formations of the Nanhua System are conformable as in the South-eastern basin. The area is the transitional zone between the inner Yangtze region and the South-eastern basin, and can provide a key to the stratigraphic correlation between these two regions. Questions such as the correlation of Liantuo and Gucheng formations can be resolved through further investigation in southeastern Hubei Province.