@article{oai:nagoya.repo.nii.ac.jp:00011527,
 author = {塚脇, 真二 and Tsukawaki, Shinji and 奥野, 充 and Okuno, Mitsuru and 大河原, 正文 and Okawara, Masafumi and 加藤, 道雄 and Kato, Michio and 中村, 俊夫 and Nakamura, Toshio},
 journal = {名古屋大学加速器質量分析計業績報告書},
 month = {Mar},
 note = {Four gigantic water reservoirs were constructed through the Khmer Dynastic period in the Angkor district, central Cambodia to irrigate during the dry seasons as well as to guard against inundations during the rainy seasons. Although these reservoirs performed their function as cores of the water networks in the district at their beginning stages, their function had gradually been unfulfilling due to filling up with sediments, and they were finally relinquished. Since no geological and archaeological investigations have been made in the bottoms of these reservers, their actual pondages at that time have been no more than inferences because their actual bottoms (=water depths) have not been distinguished. Further, there is a certain possibility that the sedimentary filling up processes of the reservoirs can be reconstructed by geological approaches using underground sediments. Accordingly, about 6-metres-deep auger drillings were carried out in the north (EB-N'), centre (EB-C) and south (EB-S) of the central part of the East Baray reservoir, one of the four reservoirs, built in the beginning of the 10th century, in August 1997. Sedimentological and micropalaeontological analyses, and radiocarbon datings of the underground sediment samples were carried out on pursuing the above-mentioned subjects The underground sediments of the East Baray are composed downwards of surface dark yellowish brown gravel bearing clayey sand (banking soil : 0.4-0.6m), reddish brown clayey sand (0.2-0.6m), yellowish brown clayey sand (0.7-1.6m), light grey sandy clay (1.1-1.8m), yellowish grey clayey sand (0.3-1.8m) and light grey gravelly fine- to coarse-grained sand (more than 1.8m). Strata below yellowish brown clayer sand thicken gradually to the south. Fresh-water sponge spicules and are frequently recognized in both yellowish brown clayey sand and light grey sandy clay. Radiocarbon datings of the underground sediments obtained from two horizons of EB-N' and one horizon of EB-S were carried out by an accelerator mass spectrometer (AMS) of the Dating and Material Center, Nagoya University. However, the age was not obtained from 200-220cm (light grey sandy clay) below the surface at EB-N'. The radiocarbon ages of sediments from 260-280cm (yellowish grey clayey sand) below the ground surface at EB-N' are 11,000±200 and 10,980±120 years BP. The age of sediments from 160-180cm (yellowish brown clayey sand) is 2540±110 years BP. Thus, strate below the yellowish brown clayey sand are undoubted alluvial deposits. Consequently, the actual water pondage of the East Baray when it constructed should be estimated at 60 million m^3 on the basis of hight of the embankment and its area of the East Baray at the present time., タンデトロン加速器質量分析計業績報告 Summaries of Researches Using AMS 1997 (平成9)年度},
 pages = {272--280},
 title = {試錐ならびに^<14>C年代よりみたアンコール遺跡東バライ貯水池跡の表層地下構造},
 volume = {9},
 year = {1998}
}