@article{oai:nagoya.repo.nii.ac.jp:00011305, author = {大平, 明夫 and Ohira, Akio}, journal = {名古屋大学加速器質量分析計業績報告書}, month = {Mar}, note = {Stratigraphy and the Holocene sedimentary environments in the northeastern Niigata Plain were studied on the basis of radiocarbon dating and diatom analysis. The Holocene sediments in the region are subdivided into peaty layer in the uppermost part, sandy layer in the upper part and silty or clayey layer in the middle and lower parts. Ages of the peaty sediments in the uppermost layer collected at Toyosaka are 3380+-130 yr.B.P. (NUTA-1338) and 2480+-160 yr.B.P. (NUTA-1271). Ages of wood fragments in the upper layer and lowest part of the lower layer collected near the L.Fukushima-gata are 4810+-110 yr.B.P. (NUTA-1336) and 9600+-280 yr.B.P. (NUTA-1211), respectively. Sedimentary environments of the region during the Holocene changed as follows. Early and middle Holocene : Brackish lagoon spread out behind the coastal barriers. Late Holocene : Sandy sediments covered the inland region. Latest Holocene : Peat bogs developed behind the coastal barriers, and lagoons in the region became small.}, pages = {3--7}, title = {新潟平野北東部における沖積層上部の<14>^C年代と堆積環境}, volume = {2}, year = {1991} }