摘要
红土台地是未来经济建设的主要场所。本文与流行的看法相反.根据地质(台地具加里东基底)、地貌(形成和保持多级台面需相对稳定环境)、第四系(厚度最薄,升降幅度小)、地热(无温泉,热流值低于50 mw/m^2)、地球化学(水的氡含量低)及微震(台地上少)等特征,以及甚至在大震时也并无强烈震害记录。认为其附近虽曾有八级大震,但却为较稳定的断块。最新构造运动速率就整个断块而论是以mm/a计,但台地内部则要小一个甚至二个数量级,是十分微弱的,故台地明显为北东—北西向断裂切割而成的较稳定断块——安全岛。
The author proposes that the red soil platform in coastal area of Fujian Province on which large- scale construction will be carried out is a rather stable fault block although there was a significant earthquake (M=8) before. This conclusion is based on the geology (the metamorphic rocks in the platform belong to Caledonian basement according to current research), geomorphology (forming and retaining several planes or terraces demand a relative stable environment), Quaternary (thin sedimental layer reveals weak vertical movement), geothermics (thermal flow less than 50 mW/m2 and without any hotsprings), geochemistry (low radon content in groundwater), microearthquake activity (rare in the platform) and there was even no intense earthquake hazard during the significant earthquake in A. D. 1604. The neotectonic active rate for the whole fault block is about 50 mm/a but one or two orders lower than that in adjacent areas. Consequently, the platform crossed by NE-and NW-extending faults is a rather stable fault block (i. e. safe island).
出处
《福建地质》
1991年第1期70-78,共9页
Geology of Fujian
