海坛岛芦洋浦平原的海进沙与风沙层序

Transgression and eolian sand sequence in Luyangpu Plain,Haitan Island, Fujian

本文研究了福建海坛岛芦洋浦平原的海进沙与风沙层序。结果表明,芦洋浦平原原是一个水深20～30m、走向NNE的海湾,全新世初期的海进沙层厚2～5m覆盖在陆相冲积和风化层上。后来,海平面波动,从台湾海峡推来残留沙超覆其上。经一段时间的正常环境后,距今约2400～2000a,由于地球气候的变化,风沙逐渐发育,厚5～10m的风沙层埋盖了海湾沉积,建造了面积68km^2的大沙坪和半封闭的泻湖。

The Haitan Island is situated in the northwestern of Taiwan Strait(119°40～54'E,25°30'～40' N), and the Luyanpu Plain is located in the north of the Island. In the early period of late Holocene epoch, Luyangpu Plain was a bay environment 20～30m deep of NNE direction, which was onlapped by a transgression sandy bed 2～5m thick. The sand transgression layer came from the Taiwan Strait in to the bay again when the sea level was fluctuating. Continuously, the sea level had risen until it came into its present position, and formed the present sedimentary environment after a period of stability. For the past 2000a of changable world climat, the eolian accumulation became intensive and a thick of eolian sand overlapped on the bottom of the bay. It' s deposition environment of claysand with many species of marine benthos fragments. A 10m thick layer of eoli(?)n sand covers whole Luyangpu Plain of 68km^2.As the result of this event, the beach of Botang Bay has been retreating simultaneity and the eolian sand resource become exhausted.Luyangpu eolian plain is a large sand tongue of importance, which may not be noticeable. Behind the sandy tongue a bay lagoon is formed as the sand tongue grows.