 หัวเรื่อง:การกระจายของแร่ดินเหนียวเคโอลิไนต์ อิลไลต์ และมอนต์มอริลโลไนต์ในขนาดอนุภาคดินเหนียวชนิดหยาบ และชนิดละเอียดของดินตะกอนน้ำพาบางชนิด ผู้เขียน: Kannica yoothong, Mitri Pukamphol, Ampawan Hutspardol สื่อสิ่งพิมพ์:pdf Abstract Seven selected soil profiles of alluvial soils from various parts of Thailand were used in the study of the distribution of clay minerals – kaolinite, illite and montmorillonite in coarse and the find clay fractions. The clay fraction of soils was first separated into coarse and fine fractions between 2.0 to 0.2 micron and smaller than 0.2 micron, respectively. The mineralogical composition of both fractions was determined by X-ray diffraction technique. The results reveal that the clay mineralogy of the alluvial soils consists mainly of kaolinite, montmorillonite and illite with kaolinite yielding the biggest proportion in most of the soils studied. Interstratified clay minerals, vermiculite, chlorite, goethite and quartz are also present in small quantities in some soil series. The distribution of kaolinite in the two fractions are nearly the same, slightly more in the coarse clay fraction (2.0 to 0.2 micron) in some soils, however slightly more in the fine clay fraction (<0.2 micron) is also observed. Montmorillonite is found in both fractions of most soils, more in the fine clay fraction than in the coarse clay fraction. Illite segregates largely in th coarse clay fraction and is found in the fine clay fraction in minor amount or does not present in some soils. Other minerals from these alluvial soils such as vermiculite, quartz and chlorite are found only in the coarse clay fraction and the interstratified clay minerals and goethite are presented in both clay fractions. From the reasons that many minerals do not segregate largely in either coarse or fine clay fraction, in general practice, it is not necessary to separate the clay fraction into coarse and fine fractions prior to X-ray diffraction examination of minerals. Separation of the clay fraction < 2 micron is satisfactory. |
หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Clay Minerals and Iron Oxides of Selected Red and Yellow Soils in Northeast Plateau and Southeast Coast, Thailand) ผู้เขียน: นางสาวอัญชลี สุทธิประการ, ศาสตราจารย์เกียรติคุณ , นายเอิบ เขียวรื่นรมณ์, ศาสตราจารย์เกียรติคุณ , Pramualpong Sindhusen, Kannica yoothong สื่อสิ่งพิมพ์:pdf AbstractA study on clay minerals and iron oxides was conducted on five selected red and yellow soils in the Northeast Plateau and the Southeast Coast mailand, using x-ray diffraction analysis and differential thermal analysis methods. The results reveal that the red and yellow soils have kaolinite as the dominant clay mineral. Vermiculite, smectite and illite are also present in minor quantities in the soils. The iron oxide content of these soils varies according to their parent materials. The iron oxide minerals found include hematite, goethite and magnetite. The clay minerals and iron oxides in these soils account for their poor fertility status and care should be taken on soil system for fertilizer application. The soils belong to Ultisols and Oxisols and can be correlated well with established soil series in Thailand. |