@article{oai:nagoya.repo.nii.ac.jp:00012795, author = {水谷, 伸治郎 and MIZUTANI, Shinjiro and 坂, 幸恭 and SAKA, Yukiyasu and 矢入, 憲二 and YAIRI, Kenji and 足立, 守 and ADACHI, Mamoru}, journal = {名古屋大学博物館報告}, month = {Dec}, note = {Size and shape properties of clastic grains of silt and siltstone are discussed using desert sands from Egypt and siltstones from Malawi; it is revealed that most of the silt grains (i.e. diameter of the grains finer then 4.0φ and coarser than 8.0φ in size) are invariably angular in shape. Once the silt grains were formed, they seem to retain their shape and even their surface features. Although the occurrence of siltstone is not so common, it frequently occurs in the geological formations within the Permo-Triassic Karroo system in the African continent. The glacial deposits named the Dwyka system has been reported from the Gondwana Land, particularly in South Africa. The occurrence of the siltstone may be related to the glaciofluvial deposits in this region. In the supplementary part of this report, we present the outline of the Database named IDARC (Image Database of African Rock Collection), and explain how to read it on the Home Page of the Nagoya University Museum open to the public.}, pages = {119--152}, title = {シルトとシルト岩}, volume = {26}, year = {2010} }