闽南、粤东全新世海平面变化

本文对7类古海面标志物的137个样品年龄数据进行沉积深度校正、构造升降幅度校正和潮差校正后,绘出闽南、粤东全新世以来海平面变化曲线。闽南、粤东出现全新世第一次高海面时间为6300aB.P.前后。闽南、粤东全新世海平面变化曲线反映海水进退的波动情况基本相似。海平面发生波动的时间从东往西逐渐推迟。海平面变化曲线与硅藻垂向变化、孢粉所反映的气候变化、滨岸沙堤形成期和古文化遗址堆积的变化有较好的一致性。

HOLOCENE SEA LEVEL CHANGES IN SOUTHERN FUJIAN AND EASTERN GUANGDONG

According to 137 datings on 7 kinds of ancient sea level indicators (intertidal zone sheli remains, tidal flat muds, lagoon muds, beach ridge sediments, beach rocks, marine ulminite and coastal beach sands), the deposit depth correction, tectonism correction and tidal correction have been made, and the sea level change curves of southern Fujian and eastern Guangdong coasts have been drawn. The Holocene sea level changes in southern Fujian can be divided into 7 periods: sea level rose step by step before 6 350 a B.P. and reached the first Holocene high sea level; declined step by step from 6350 to 6 000 a B. P.; rose step by step from 6 000 to 3 700 a B. P.; declined step by step from 3 700 to 3 250 a B. P.; rose step by step from 3 250 to 2 200 a B. P.; declined slightly from 2 200 to 1 000 a B. P.; rose slowly in the past 1 000 years. The Holocene sea level changes in eastern Guangdong can be divided into 6 periods: sea level rose step by step before 6 300 a B. P. and reached the first Holocene high sea level; declined step by step from 6 300 to 5 900 a B. P.; rose step by step from 5 900 to 3 400 a B. P.; declined step by step from 3 400 to 2 700 a B. P.; rose step by step from 2 700 to 1 400 a B. P.; declined slightly from 1 400 to 700 a B. P. From the sea level change curves, the Holocene first high sea level happened in 6 300 a B. P. The sea level change curves of southern Fujian and eastern Guangdong are similar. The fluctuation time of sea level was retarded from southern Fujian to eastern Guangdong coast. According to our research in the Zhujiang Delta, western Guangdong and Guangxi coasts, the retard also happend along these coasts westwards. It seems that there is a universsality in this retard from east to west coasts in South China. The sea level changes were in accordance with the vertical change of diatoms in core samples, the climate changes reflected by sporo-pollen analyses of samples, the deposition periods of sand bar and the shifting of ancient culture relics sites. When the sea level rose, the percentage of marine and brackish diatoms in sediments increased, the climate was hot and wet as reflected by the sporo-pollen analyses. The high sea level periods also were the main formation periods of the beach ridge. The distributive elevation of ancient culture relics sites was heigh when sea level in a high elevation; the shoreline and the ancient culture relics sites moved forward in lower sea level period.