海西—印支期上扬子南缘碳酸盐岩台地边缘沉积特征、演化及其控制因素

海西—印支期上扬子地块发育稳定型的碳酸盐岩大台地,在碳酸盐岩台地南缘台地边缘沉积体系发育,主要包括4种沉积类型:台地边缘滩,台地边缘礁、台地前缘斜坡、滩(礁)间海。据海西—印支期台缘沉积发育及分布特征,可分为4个沉积演化阶段:中泥盆世—晚泥盆世(SS1),台缘沿弥勒—师宗—晴隆—南丹—河池一线呈带状分布,台缘礁滩发育;早石炭世—早二叠世早期(SS2-SS3),台缘沿晴隆—六盘水—安顺呈带状分布,台缘生屑滩发育;早二叠世晚期—晚二叠世(SS4),沿贞丰—紫云—罗店—河池—柳州—娄底呈带状分布,台缘滩、台缘礁交互发育;早三叠世—中三叠世(SS5),沿贞丰—镇宁—贵阳—福泉一线呈带状分布,早三叠世主要发育台缘鲕粒滩,中三叠世台缘礁占优势。这4个阶段的台缘沉积特征表明:台地边缘礁滩沉积体系垂向演化受海平面变化控制,横向迁移主要受同沉积断裂控制,不同类型生物的出现和绝灭控制台缘生物礁滩的类型及特征。

The Sedimentary Characteristics, Evolution and Controlling Factors of Southern Margin, Yangtze Carbonate Platform During the Hercynian-Indosinian Stage

The carbonate platform developed on the Yangtze block during the Hercynian-Indosinian stage. Platform margin depositional system developed in the southern carbonate platform including four sedimentary types: the beach of carbonate platform margin, the reef platform of carbonate platform margin, platform margin slope and the sea between beach (reef). According to development characteristics of platform margin, four stages can be divided: the platform margin strip distributed along the line of Mile-Shizong-Qinglong-Nandan-Hechi during the Middle Devonian-Late Devonian(SS1), the reef-bank of platform margin developed widely;the platform margin strip distributed along the line of Qinglong-Liupanshui-Anshun during the Early Carboniferous-early Early Permian(SS2-SS3), platform margin beach developed widely;the platform margin strip distributed along the line of Zhenfeng-Ziyun-Luodian-Hechi-Liuzhou during the the late Early Permian-Late Permian(SS4), the reef-bank of platform margin developed widely;the platform margin strip distributed along the line of Zhenfeng-Guiyang-Fuquan during Early Triassic-Middle Triassic(SS5), platform margin oolitic beach developed in the the Early Triassic, platform margin dominated reef developed in the Late Triassic. The study proved that horizontal migration of platform margin was mainly controlled by syndepositional faults, the vertical sequence evolution of platform margin was mainly controlled by sea-level change, the type of margin reef-bank was controlled by different types of carbonate secret organisms.