西秦岭造山带泥盆纪沉积地质学和动力沉积学研究:西秦岭中带泥盆纪小型克拉通盆地的沉积特征及盆地格局

秦岭微板块位于商丹－武山和勉略－巴山弧断裂之间。泥盆纪时期，微板块主体处于稳定的小型克拉通盆地背景。本文仅从西秦岭中带泥盆系入手，探讨该区泥盆系的沉积体系和盆地格局。小型克拉通盆地北带的西汉水小区以古岛屿滨岸－陆棚沉积体系（艾菲尔期）、碳酸盐台地－生物礁沉积体系（吉维特－弗拉斯期）、深水盆地和泥质浊积岩沉积体系（法门期）为特征。南带武都小区则以陆棚碎屑岩（艾菲尔期）和缓坡型台地－陆棚沉积体系（吉维特－法门期）为主，该小型克拉通，泥盆纪时期是一稳定块体，到二叠纪－三叠纪才受中秦岭裂陷槽分隔成两个块体。

SEDIMENTARY GEOLOGY AND DYNAMIC SEDIMENTOLOGY OF THE DEVONIAN STRATA IN THE WEST QINLING OROGENIC BELT: SEDIMENTARY CHARACTERISTICS AND FRAMEWORK OF THE SMALL-SCALE DEVONIAN CRATONIC BASIN IN THE MIDDLE BELT OF THE WEST QINLING OROGENIC BELT

The Qinling microplate lies between the Shangnan-Danfeng--Wushan and MianxianLueyang-Bashan arc faults.During the Devonian, the bulk of it was in a stable small cratonic basin.The present paper focuses on the Devonian sedimentary systems and basin framework viewed from stratigraphy and sedimentology of the Devonian strata in the middle belt of West Qinling orogenic belt.The Xihanhui microprovince in northern cratonicbasin is characterized by the terrigenous littoral-shelf depositional systems around palaeoislands(Eifelian),carbonate platform-organic reef depositional systems(Givetian to Frasian),and deep--water basin and muddy turbidite depositional systems(Famennian),while the Wudu microprovince in southern cratonic basin is dominated by the terrigenous shelf depositional (Eifelian) and ramp-type carbonate platform-shelf depositional systems(Givetian to Famennian).The stable cratonic basin was broken up into two parts by the central Qinling rift trough during the Permian to Triassic.