通过对华南泥盆纪生物礁现有资料和作者获得的实际材料的分析研究,编制了华南早、中、晚泥盆世生物礁分布图。华南泥盆纪生物礁最早出现在埃姆斯期晚期,分布层位由西南向北东逐渐变新。华南泥盆纪生物礁分布和演化具有3方面的特征:(1)不同类型生物礁演化差异很大:浅水礁变化最大,台缘礁变化次之,深水礁几乎没有变化;(2)主要造礁生物随时间演替明显:床板珊瑚(埃姆斯期)→床板珊瑚、四射珊瑚和层孔虫(艾菲尔期)→层孔虫和四射珊瑚(吉维特期)→层孔虫(弗拉期)→菌藻类(法门期);(3)生物礁数量和规模在吉维特期出现峰值。研究表明:华南泥盆纪生物礁的发育受区域和全球性因素的共同制约,其中温度、大气中CO2分压(PCO2)和植被—森林生态系等全球性因素对华南泥盆纪生物礁有重要影响。
Based on the data of the Devonian bioreefs, we compiled the distribution maps of the Early, Middle and Late Devonian bioreefs in South China. The earliest Devonian bioreefs appeared in the Late Emsinian. The spatiotemporal distribution of the Early, Middle and Late Devonian bioreefs shows that development of the Devonian bioreefs gradually migrated from the southwest to the northeast in South China. Their distribution and evolution are characterized by:(1)Different bioreefs have obviously different evolution processes. The greatest and second-greatest changes occurred in the shallow-water bioreef and platform marginal bioreef, respectively, while almost no changes occurred in deep-water bioreef during the Devonian. (2)The replacement of major reef-builders were obvious from the Early Devonian to the Late Devonian: Tabulate corals(Emsian) to tabulate and rugose corals and stromatoporoids(Eifelian) to rugose corals and stromatoporoids(Givetian) to rugose corals and stromatoporoids(Frasnian) to cyanobacteria(Famennian).(3)Bioreefs reached apex in size and quantity during the Middle Devonian Givetian Age. The main controlling factors of the Devonian bioreefs in South China include both local and global factors. The former are considered to be transgression-regression cycles and terrigenous clastic supply. The latter are considered to be changes of paleotemperature, PCO2 and vegetation-forest ecosystem.