Three series of solid solutions of orthopyroxene structure, (Fe, Mg )SiO3, (Co, Mg)SiO3 and (Ni, Mg)SiO3, were synthesized, using high pressure sintering technique. Unit cell parameters of the synthesized pyroxenes were determined at room temperature. The deviation from Vegard's law is remarkable for both iron and nickel pyroxene series, whereas almost absent for cobalt one. It is suggested that the dominant factors which determine the distribution of ions among nonequivalent sublattice sites are 1) the difference in effective sizes of both ions (for the case of (Fe, Mg )SiO3) and 2) the crystal field stabilization energy (for the case of (Ni, Mg )SiO3). The nearly ideal behavior of (Co, Mg )SiO3 is a result of the compensation between these two competing factors.
Uranium deposit samples were radiochemically separated for thorium, protactinium and uranium and each fraction was submitted to alpha ray spectrometry for the determination of 238U, 234U, 232Pa, 232Th and 230Th. In an ore body of Ningyo-Toge Mine, Okayama, Japan, the relationship between the uranium isotopes and their daughter nuclides indicates an extensive migration of uranium. The migration was also verified by the high radium and protactinium contents of a manganese nodule sample. The thorium-bearing samples in a neighboring district were also analyzed to elucidate the origin of these uranium deposits. The ages of two secondary uranium minerals in Tono district, Gifu, were estimated to be 5×103 y and 34×103 y. on the basis of their isotopic compositions. For the radioactive phosphate samples in Noto district, Ishikawa, secondary enrichment of uranium by phosphate was confirmed with their isotopic compositions and their phosphate contents.
Paper chromatographic determination has been studied for plant pigments in core samples from Lake Kizaki-ko (maximum depth: 28.5 m, area: 1.413 km2). Eleven kinds of pigments were fractionated and determined by this method, and are called fractions No. 1 through No. 11 in order of their Rf values. Nos. 1 through 3 correspond to carotenoids, No. 4 to phaeophytin a, No. 6 to chlorophyll a, and other fractions to chlorophyll derivatives. Total amount of the pigments remarkably decreases with core depth from surface down to 20 cm, and remains practically uniform in deeper layers. Among the pigments, fractions No. 4 (phaeophytin a), No. 6 (chlorophyll a) and No. 11 are predominant with 159, 445, and 125 ppm as of dry samples respectively in surface sediments. Their concentrations strikingly decrease with depth in the upper layers from 74, 98, and 63 pprn at a depth of about 5 cm to 14, 6.7, and 12 ppm respectively at a depth of about 20 cm. Vertical distribution of various pigments as indicated by their percentage in total pigments shows that the net-decomposition rate (decomposition rate—production rate) of each pigment in the sediments is in the following order: Chlorophyll a (No. 6) > No. 8 > No. 1, No. 2, No. 3 > Phaeophytin a (No. 4), No. 11, No. 9, No. 10, No. 7 > No. 5.
The boron content of siliceous sinters is related primarily to the boron concentration in the original solution from which they deposited, and is also affected by their degree of crystallization, as expressed in terms of water content. When the ratio of B/SiO2 in the sinter to B/SiO2 in the solution is denoted by r, then r can be expressed as a function of water content of the sinter: log r=a+b log(H2O), where a and b are constants under given pH and temperature conditions.