2021-08-04T23:41:56Zhttps://soar-ir.repo.nii.ac.jp/oaioai:soar-ir.repo.nii.ac.jp:000119052021-07-05T00:36:58Z1169:1170Grain-size analysts COmbined settling tube method with hydrometer method for muddy sand sediments沈降天秤法と比重計法の組合せによる泥質砂堆積物の粒度分析法岸, 誠一36491公文, 富士夫36492grain-size analysishydrometersettling tubesievingweight correctionGrain-size analysis of muddy sand or sandy mud is a matter of trouble, because the sed1- ments abundantly include both sand and clay grain size which behave differently in principle. The analysis by a single method needs a very long time and/or a large labor for one specimen. The new procedure proposed here is a combination of a settling tube method for sandy fractions and a hydrometer method for muddy fractions. The hydrometer analysis is performed according to an ordinary procedure. Then wash the sample on a 4.5-phi standard sieve. Dry the fractions rested on the sieve, and weigh it. After then, analyze the coarse fractions by a settling tube method. The settling tube method is a newly-formed system which uses an electric balance and a computer. Make the two cumulative frequency curves, and combine them by ca1- culation. Theoretically, both curves should fit at 4.0 phi of settling-size grade, on the basis of the detailed research of effects by 4.5-phi sieving, Both curves, however, often differ slightly at 4.0 phi. Therefore, they are shifted to each other at 4.0-phi grade by changing the total weight of the used sample, namely "weight correction". This procedure takes 4 days to analyze 15 samples from coarse-grained sand to clay.Article堆積学研究会報. 38:101-106 (1993)journal article堆積学研究会1993application/pdf堆積学研究会報381011060285-1555AN10553692https://soar-ir.repo.nii.ac.jp/record/11905/files/taisekigaku-38.pdfjpn