关键词: 地层划分, 晚第四纪, 福州盆地

Abstract: Fuzhou basin is tectonically located in the eastern part of South China fold system,within the Fuding-Yunxiao Fault depression area of East Fujian volcanic depression zone. Based on detailed logging,and combined with results of other researchers,the preliminary summarization on sedimentary characteristics of late Pleistocene of Fuzhou basin is done. The depositing of Fuzhou basin began from about 56.5ka BP,sediments comprise gravel,sand,clay and silt,showing a depositional sequence with the granularity becoming small from lower to upper,and a bigger variation of lithologic properties in horizontal direction. There are three silt layers in late Quaternary strata of Fuzhou basin. The first and second layers developed during the middle and late Holocene,the depositing time of them is about from 7.86ka BP to 3ka BP to 3.08ka BP and they are the results of “Changle Transgression”; the third developed during the late of late Pleistocene and the depositing time is about from 44ka BP to 20ka BP and it is the result of “Fuzhou Transgression”. The buried late Quaternary sediments in Fuzhou basin can be divided into upper Pleistocene series and Holocene series,which include four formations from old to new. They are Longhai formation(Q³_pl),Dongshan formation (Qhd),Changle formation (Qhc)and Jiantian formation (Qhj) respectively. The Longhai formation can be divided into three members,the sediments of the lower member are celadon,yellow gravel and moderate coarse sand; the middle member is of gray clay,silt,sand and gravel,or interbed of silty clay and fine sand; the upper member is of yellow moderate coarse sand. Dongshan formation comprises gray silty sand and clay. Changle formation can be divided into two parts,the lower part is of interbed of silt and flour sand; the upper is of gray and plumbeous silt or douke silt. The Jiantian formation comprises light gray,brown clay.

Key words: strata division, late Quaternary, Fuzhou basin