The mountainous district at the eastern end of the Chugoku mountains in the central part of Hyogo Prefecture is called “Bantan Sanchi, ” and is composed mountains rising 1, 000-1, 300m above sea level. The Mineyama Highland and other; small plateaus, at the height of 800-1, 000m, are located south of the watershed in these mountains. We investigated the geomorphology and block stream in these highlands. The results obtained can be summarized as follows.
1) The surface of these highlands consists of smooth debris-mantled slopes, block streamI and IT, and upland fans.
2) A debris-mantled slope has a smooth surface with an inclination less than 25°, and exists mainly in relatively higher areas of the highland. It is composed mainly of andesitic rocks and is covered by Kuroboku (black soil) and thin debris deposits on the surface. Blocks 3-4m in size sometimes lie on the surface. A block stream measures less than 500m in length and less than. 40m in breadth with an inclination below 10°, and is seen at lower areas contiguous to the smooth debris-mantled slope. The block measures less than 1-5m in size and the thickness of the block stream deposit is less than approximately Sm. An upland fan usually lies on the downstream side, of a smooth debris-mantled slope or block stream. It incises the slope and block stream on the upstream side and overlies it on the downstream side. It is composed of small and large blocks and coarse sand as the matrix.
3) Geomorphic chronological characterization of these highlands may be achieved using Kikai- Tozurahara volcanic ash (K-Tz, fall of 70, 000-80, 000 years ago), Aira Tn volcanic ash (AT, fall of 24, 000-25, 000 years ago), Misen pumice (MsP, fall of 16, 000-18, 000 years ago), and Akahoya volcanic ash (Ah, fall of 6, 300 years ago) components of the widespread tephra.
4) The thick weathered crust and its rock core, which is formed on these highlands composed of andesitic rocks, were produced by deep chemical weathering followed by periglacial mass movement in the cold period of the Last Glacial Age.
5) The smooth debris-mantled slope was formed as a result of periglacial mass movements-that is, frost shattering, frost creep, slope wash, and. solifluction-on the abovementioned highland surfaces.
6) The core stones were first rafted down slopes by solifluction from their initial positions on summits, smooth slopes and interfluves, then moved downvalley as “block streams” at the bottom, finally, flowed as block streams.
7) As block stream I overlying K-Tz ash was covered by AT and MsP ash, it was formed before 24, 000 y. B. P., perhaps during the first half of the Last Glacial Age. Block stream II was formed between the fall of MsP and that of Ah-that is, in the Late Glacial Age.
8) As can be presumed from the landform arrangement and the Ah ash that covers it, the formation of upland fans seems to have occurred as a result of erosion of the smooth debris-mantled slope and block stream and the resultant deposition of debris on the downstream side which were caused by the action of water flow produced by hydrological change with the warming of the climate.

View full abstract

Recent studies of river terraces in some mountainous regions in Japan revealed that the sequence of river terrace development during the late Quaternary was similar for adjacent rivers, showing that climatic changes had the same effect on all the adjacent drainages. However, landform processes in river basins are affected not only by climatic changes but also by the geomorphic and geologic conditions of the basins. Thus, landform development in a given drainage should vary corresponding to the geomorphic and/or geologic conditions subject to the same climatic changes. To verify this, the author examined the differences in landform development during the Late Glacial and the Post-Glacial Ages among eight drainages around the Matsumoto Basin (Fig. 1). The results are as follows:
1) Analyses of the areal distribution and interpolated profiles of fluvial surfaces (Figs. 1 and 3) suggest that the processes of fan formation are divided into three types. In the drainages of Chigawa(1), Ashimagawa(2) and Nakafusagawa(3), , alluvial fans aggraded during the Late Glacial and the Post-Glacial Ages, but the process is no longer ongoing at present. In the drainages of Karasugawa(4), Kurosawagawa(5) and Susukigawa(8), active aggradation of alluvial fans has continued since the Late Glacial. In the Kusarigawa(6) and Metobagawa(7) drainages, aggradation of alluvial fans during the Late Glacial and the Post-Glacial Ages was less active than in other drainages.
2) Mountain slopes in the drainages are divided into four units by three marked convex breaks in the slope (Fig. 2). The lower two units, i.e., higher and lower dissected slopes, were formed during the Late Glacial and the Post-Glacial Ages as a result of the effect of running water combined with the change in climate from cold-dry to warm-humid conditions. Based on the ratio of the area of the dissected slopes to the area of all mountain slopes (PD), the drainages are classified into three groups which are at different stage of dissection. In the Chigawa(1), Ashimagawa(2) and Nakafusagawa(3) drainages, the values of PD are large, while in the drainages of Kusarigawa(6) and Metobagawa(7), the values are small. The Karasugawa(4), Kurosawagawa(5) and Susukigawa(8) drainages have intermediate PD values (Fig. 5).
3) The types of alluvial fan development correspond to the different dissection stages of drainage. This fact indicates that the debris forming the alluvial fans was produced and transported through the development of the dissected slopes (Fig. 6).
4) Statistical analyses of the relationships between PD, dispersion of altitude (D) and geology give the following results. The value of PD increases with D (Fig. 7), showing that the dissected slopes were developed widely where D is large (Fig. 9). On the other hand, the value of PD varies with geology at the same value of D, though the value of PD increases with D for the same geology (Fig. 10). These relationships indicate that the large-scale relief and geology played independent parts in the development of the dissected slopes (Fig. 11).
5) The value of RPD, which is the residual after the generalized PD is subtracted from the observed one (Fig. 12), decreases with increase of RH (Fig. 15), which represents the generalized 'H (altitude) subtracted from the observed one (Figs. 13 and 14). This fact indicates that the value of PD increases as H decreases under the same relief and geological conditions, implying that the dissected slopes have developed gradually, from valley bottoms to the upper parts of valley side slopes. Thus, it is concluded that relief, geology, and altitude participated independently in the development of the dissected slopes.
The processes and development of landforms in the drainages are summarized as follows. With climatic change, the dissected slopes were formed on mountain slopes in all the drainages during the Late Glacial and the Post-Glacial Ages.

View full abstract

It is the object of this article to analyze the changing points of view with which the geography of Japan has been described in the United States since World War II, using world geography textbooks for American high school students as a data source. The research shows that while some points of view have not changed during the time, a number of viewpoints have changed.
1. Unchanging views
Japan has been considered a country with a high population density, which is regarded by some as a problem and by others as a resource. Many textbooks emphasize that Japan began to modernize after the arrival of Commodore Perry, and that thus the United States contributed to her modernization.
2. Changing points of view Many textbooks call Japan “the Britain of the East” because of the similarity between the natural environments of the two countries. But this point of view prevailed mainly before andd during World War II. Right after the war, textbooks began to point out that Japanese society had been very feudalistic before the war. This point of view may have reflected the American occupation policy of that time, through which the United States wanted Japan to turn away from the past and make a new start as a democratic country.
Japan's rapid economic growth with American assistance was stressed in the textbooks published in the 1960s. Many of them also explained that Japanese lives were becoming westernized and that traditional life styles were changing in response to the economic growth.
The authors of textbooks in the 1970s considered Japan an example of a country which had developed from a non-industrial society into an industrial society: In the 1980s, however, because of Japan's economic strength, she is described as a rival menacing the United States' position. Some authors are willing to study the factors involved in Japan's success; others emphasized the United States' unfavorable balance of trade with Japan.
In conclusion, the times and the relationships between countries appear to be reflected in the points of view from which regional geography is described.

View full abstract