The hydrothermally altered areas by fumarolic activity at Steamboat Springs, Nevada, USA were discriminated using the characteristics of the spectral absorption of iron from 0.45 um to 0.60 μm and OH-bond absorption around 2.2 μm. For several years, the importance of using 2.2 μm spectral characteristics for finding highly altered areas by clay minerals has been pointed out. The ratio of 1.6 μm/2.2 μm has also been used to delineate clayish altered areas. This ratio, however, is high not only at the altered areas but also at the vegetated areas, and the distinction of clayish altered areas from vegetated areas by using only this ratio is rather difficult. Some attempts were performed to distinguish hydrothermally altered areas from unaltered areas as well as from vegetated areas by using the spectral characteristics of OH-bond absorption around 2.2 μm. From detailed analyses of remote sensing data of the Steamboat Springs area, it has become clear that the radiance difference from 1.65 μm to 2.2 μm may be an important index to discriminate hydrothermally altered areas from unaltered areas and vegetated areas.
The outdoor exposure test and accelerated deterioration tests, such as the freezing and thawing test and sodium sulfate soundness test on dolerite have been conducted to study the deterioration characteristics and durability of material rocks for use as riprap of rock fill dams in each test condition. From a series of tests, the following results have been obtained. 1) The deterioration types of rocks in the freezing and thawing test are basically identical with those in the outdoor exposure test. In these tests, the deterioration types of rocks can roughly be categorized into five groups, N (horizontal), N′ (almost horizontal), A (stepped), B (smoothly curved) and C (intermediate between A and B) based on weight loss curve characteristics. 2) The change types in physical parameters, such as absorption, dry density and dynamic modulus of elasticity with time in the outdoor exposure test are identical with those in the freezing and thawing test. Relationship between change types in physical parameters and rock properties are also identical in these two tests. 3) Even though in the case that any relationship between initial physical parameters and deterioration types can't be recognized at all in the outdoor exposure test, close relationship can be recognized in the freezing and thawing test and the sodium sulfate soundness test. 4) In the case where close relationship between initial physical parameters and deterioration types can be recognized in the outdoor exposure test, criteria values for durability evaluation are all nearly equal in the outdoor exposure test, freezing and thawing test and sodium sulfate soundness test. Therefore, in this case, durability of rocks under natural environments can accurately be evaluated by accelarated deterioration tests. 5) In the case where any relationship between initial physical parameters and deterioration types can't be recognized at all in the outdoor exposure test, criteria values for durability evaluation in the freezing and thawing test are different from those in the sodium sulfate soundness test. Namely, deterioration characteristics of such material rocks can't be considered to have close relationships among these accelerated deterioration tests.
Geological and geomorphological invesigation was performed in the Kanto mountainous land to study the relationship between geology and landslide topographies in the Sambagawa terrain where crystalline schist is distributed. Landslide topographies were found to be abundant in pelitic and basic schist ranges and scarce in siliceous schist, psammitic schist, and massive basic rock ranges. It was elucidated that the landslide topographies have the size and the moving direction, both are controlled by the attitude of the basement rocks. The landslide topographies that show the movement about parallel with the dip direction of the basement rocks exceed the other landslide topographies in their number and in their size.
The fundamental information on the pore structure of coal measure rocks contributes not only to study of physics of fluid flow through the rocks, but also to that of the mechanical properties such as water effect upon the strength of the rocks. From this point of view, investigation were made on measurement of the pore size distribution of coal measure rocks by mercury penetration and correlation it with the several physical characteristics of these rocks. The results are summarized as follows; 1) Each coal measure rocks, that is, sandstone, sandy shale, shale and coaly shale, shows its characteristic pattern of pore size distribution. These characteristics can be represented numerically by using the pore volumes corresponding to the specifically defind ranges of pore radius. 2) It is possible to determine approximately the internal specific surface area of a rock from the pore size distribution. 3) There is a correlation between the pore volume corresponding to the range of radius 37.5 Å≤r<103 Å and the equivalent montmorillonite content determined by methylene-blue adsorption method, which significantly affects the mechanical properties of coal measure rocks. 4) The Young's modulus of the solid part of rock, which is calculated from the mercury penetration curve, shows that this modulus is fairly greater than that of the rock, which consists of pore and solid parts.