New data on isotope geochemistry of helium as well as more realistic approach to processes in the upper atmosphere stimulated a revision of the aeronomic problem of helium. If we adopt the maximum values of ³He and ⁴He fluxes from the solid earth into the atmosphere (which are equal to 80 and 4.10⁶ atoms/cm² sec, respectively), then a balance of both helium isotopes in the atmosphere can be provided by a mechanism of thermal escape of helium at the average temperature of thermosphere T_a = (1260 ± 40)°K. Possibilities of further study of the problem are discussed.

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Rb-Sr ages of biotite from the southern flank of Mt. Everest, eastern Nepal, range from 14.1 to 1.3m.y., the youngest biotite coexists with muscovite of 7.3m.y. These different ages for different samples reflect the difference in cooling history related to the uplift of the Himalayas. The biotite ages decrease with increasing distance from the high mountain range, suggesting that the high range, i.e., the northern area, was uplifted earlier than the southern area. The relationship between the ages and altitudes of sampling sites indicates that the uplift rate of the northern area was 0.60 mm/yr.

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Geochemical characteristics of terrestrial ferro-manganese nodules collected from various locations have been discussed through the study on major and minor chemical components for various sizes of the nodules. Manganese dioxide content of terrestrial ferro-manganese nodules varies from several to more than 20% with size from micronodule level of less than 0.1 cm and ordinary size of about 1 cm in radius. Minor element Co which is considered to be taken into nodules as tri-valent ion is very much concentrated as compared with bi-valent ions such as Ni, Zn, Cd, Pb and Cu which may be said to be captured on almost the same order of magnitude. Micro-nodules are depleted in manganese but enriched in iron. The chemical composition of the nodules changes very much with their size up to 0.2-0.3 cm in radius, while it remains almost similar to one another for larger size than 0.3 cm. The trend of minor element content with respect to size clearly shows that iron plays the most important role in the process of minor element concentration at the early stage of formation of micro-nodules, and that manganese dioxide taken into micro-nodules along with the growth of nodules becomes a predominant component for the concentration of minor elements such as Co, Ni, Cd, Pb and Cu in the later stage. Their contents then increase together with the growth of the nodules.

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Rare-earth element (REE) geochemistry on the igneous rocks from the Galapagos Islands has been discussed on the basis of precisely determined REE data for twenty rocks including alkali-olivine basalts, tholeiites, differentiated effusive rocks (ferrobasalt, icelandite and trachyte), plutonic rocks (eucrite and ferrobasalt) and inclusions of mafic and ultramafic compositions (gabbro and peridotite). It is disclosed that REE patterns of alkali olivine basalts from the Galapagos Islands have some features different from those observed in alkali olivine basalts from other regions. That is, alkali olivine basalts from the Galapagos Islands have essentially the same features in REE patterns as those seen in tholeiitic rocks from the same Islands and the ratios of normalized values between Ce and Yb are 2-4, which are small compared with the corresponding ratios of the typical alkali basalts. Most of REE patterns obtained in this study are similar to each other i.e., upward convex curve in the light and middle REE span with monoclinic rectilinear line in the heavy REE span, irrespective of a wide range in the major element compositions. These REE patterns appear to have an inflection point around the position of Gd, Th, Dy or Ho, mainly at Ho. These REE patterns most commonly observed in this study are considered to correspond to solid-type (light REE depleted) phase or to correspond to mixtures of conjugate solid-type and liquid-type (light REE enriched) phases as a consequence of incomplete separation of the two phases. It is suggested that the liquid-type phase was generated by the small-scale convection in the asthenosphere and that the liquid-type phase and the remnant solid-type phase were mixed at the top of the asthenosphere. We have considered that the essential features in these REE patterns were established during the processes in the asthenosphere and that fractionation process in the lithosphere gave rise to differentiation of only major elements and, during these processes in lithosphere, REE (except Eu) have been uniformly enriched or depleted with little change in the shape of REE patterns. It is probable that terrace-shaped REE partition pattern having the inflection point at Ho played a leading role in characterizing the shape of these REE patterns.

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The concentrations of Ca in the surface and deep waters of the North Pacific and the Bering Sea have been determined with a highly precise method. The deep water contains Ca relative to chlorinity by 0.8% more than the warm surface water of the western North Pacific, whereas it contains Ca by only 0.4% more than does the cold surface water of the northern North Pacific. Based on the results the amount of Ca dissolved in the deep water column of 4km long is calculated to be 9gCa/m²/yr. In the surface water of the productive Bering Sea, alkalinity is found to be controlled chiefly by the formation and decomposition of organic matter rather than the formation and dissolution of CaCO₃. Furthermore a plot of Ca versus potential alkalinity defined by BREWER et al. (1976) gives virtually a slope of 0.5 for upper waters above 1.5 km depth. It, however, is difficult to demonstrate the relation between Ca and alkalinity for the deep water collected from the northern North Pacific alone.

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