温州沿海平原晚更新世以来的海相地层特征及沉积环境

沿海地区的海相地层记录了极其丰富的环境信息，研究海相层的地层特征和沉积环境，对理解古环境演变的过程、探讨沉积记录对海陆变迁的响应机制具有重要意义。QTZ1孔位于温州瓯江口北侧平原，根据岩石地层和磁性地层资料，钻孔34 m处为Qh/Qp3界线，91.5 m处为Qp3/Qp2界线。综合考虑刺甲藻、环纹藻的环境意义，钻孔沉积物粒度及微体化石组合的分析结果表明，温州沿海平原晚更新世以来共识别出3套海相地层单元，第二海相层和第三海相层之间发育有完整的陆相沉积层。沉积动力条件经历了低能(Qp3)→中低能(Qp3)→中高能(Qp3)→低能(Qp3)→高能(Qp3)→中低能(Qp3)→中低能(Qp3)→低能(Qp3)→低能(Qh)的演化过程。受海平面变化影响，研究区晚更新世沉积相变化频繁，以海陆过渡相、陆相和局部的浅海相为主，全新世沉积相以浅海相为主，全新世末期逐渐转为滨海相。

Marine stratigraphy since Late Pleistocene on Wenzhou coastal plain and its depositional environment

Coastal deposits are critical important for revealing sedimentary environmental changes and their mechanisms. The Hole QTZ1 is a borehole located in the coastal plain of the northern Oujiang estuary of the Wenzhou city. Lithostratigraphy and paleomagnetic stratigraphy of the cores suggest that the boundary of Qh/Qp3 is located at 34 m in depth, while the boundary of Qp3/Qp2 at 91.5 m. The microfossil assemblages of dinoflagellates and cyclostriatum, and the grain size data of the sediments suggest that there are three marine stratigraphic units since late Pleistocene in the coastal plain of Wenzhou, with a continental deposit between the 2nd and 3rd marine layers, which recorded an evolutionary process from low energy(Qp3) to medium low energy (Qp3), medium high energy(Qp3), low energy (Qp3), high energy(Qp3), high energy (Qp3), medium low energy(Qp3) and low energy (Qh). With sea level changes, the Late Pleistocene deposits vary frequently by alternation of marine and continental transitional facies, continental facies and local neritic facies. The Holocene sediments are dominated by neritic facies, which gradually turn to coastal facies at the end of Holocene.