Landforms are shaped by tectonic movement and sculptured by denudational processes. Davis (1899) deduced landform development by denudational processes, postulating prolonged stillstand of a landmass following rapid uplift, but W. Penck (1924) emphasized that land forms were formed by tectonic and denudational processes proceeding concurrently at different rates. These two distinctive views of tectonics and denudation in geomorphology have been discussed many times, but actual conditions of these processes have rarely been assessed quantitatively.
Schumm (1963) and Bloom (1978) estimated modern rates of uplift to be much greater than those of denudation, and supported to some extent the Davisian assumption of rapid uplift of a landmass, which allowed little denudational modification of the area during the period of uplift. Recent geomorphological study has achieved many excellent results concerning tectonic and denudational processes and their products, but landform development by concurrent tectonics and denudation has scarcely been investigated intensively.
As a result of the author's estimate in Japan (Yoshikawa, 1974), modern rates of uplift are generally greater than those of denudation, but denudation rates are greater than or approximately equal to uplift rates in high mountains of Central Japan and on the Pacific slope of Southwest Japan; in these mountains both rates are usually of the order of 1mm/yr. These mountains have been rapidly uplifted and intensely denuded in the Quaternary. Landform development of these mountains, therefore, should be explained not by the Davisian scheme, but by the Penckian.
When a landmass is uplifted at a constant rate, the area increases its relief with uplift, being sculptured by rivers. Denudation rates become greater and approach uplift rates. Ultimately both rates become equal, and steady-state landforms in dynamic equilibrium of uplift and denudation are accomplished, as far as the landmass is continuously uplifted at the constant rate (Plirano, 1972, 1976; Ohmori, 1978). Landform evolution by uplift and denudation, therefore, can be divided into the following three stages; (1) the developing stage that landforms approach steady state by concurrently proceeding uplift and denudation, (2) the culminating stage that steady-state landforms are maintained in dynamic equilibrium of uplift and denudation, and (3) the declining stage that landforms are reduced down to sea level by denudation when uplift ceases. Landform evolution passes through these three stages in different duration periods according to various rates of uplift and denudation as well as duration periods of uplift.
Supported by the interpretation that erosion surfaces fragmentarily distributed in Japanese mountains are remnants of peneplains in previous cycles, the Davisian scheme of landform development has survived in Japan, where active uplift and intense denudation have proceeded concurrently in recent geologic time. It was, however, clarified in the upper drainage basin of the Waiapu River, northeastern North Island, New Zealand, that erosion surfaces in the hills, about 500 to 700m above sea level, were formed nearly at the present height probably by periglacial processes and fluvial transportation of debris in the last glacial age (Yoshikawa et at., in preparation). This suggests that there is a possibility that a considerable part of erosion surfaces in Japanese high mountains is also of the similar origin.
Geomorphological study in tectonically active and intensely denuded regions, such as Japan, will produce invaluable information of landform evolution by concurrent tectonics and denudation. This will contribute to further development of geomorphology.

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The housing development of hilly regions always accompanies the topographical trans-formation. The present study attempts to measure and explain the relationship between the progression of housing developments and the original surface of land in the northern hilly region of the Osaka plain by applying the “mesh” method to micro-topography. The results obtained are as follows:
1. The front of housing developments moved from farm land to forest regions. Senri Hill being the hub, it first proceeded from the outer fringes into the interior and then moved back again to the outer zones. As population increased, bus and railroad lines developed. Consequently, the time required to reach the nearest station decreased from twenty or thirty minutes to ten or fifteen minutes.
2. The main agents of housing developments gradually shifted from public corporations to private enterprises. Capital investment, machinery used, construction methods, and type of organization changed in the course of time in direct proportion to the ups and downs of economic conditions. Emphasis on housing supply shifted from quantity to quality. Underlying causes that compelled the compact and good quality housing led to high land prices, while topographically suitable construction sites were limited. And the stag-nation of purchasing power followed.
3. As Senri is the diluvial plateau lacking ground water resources, it had been left unused and remained sparsely populated until the 1960's and regarded as an empty and unproductive land, in spite of the fact that it was only fifteen kilometers to the center of Osaka City. Thus land prices were less expensive. This area was transformed into Senri New Town by an economically efficient cut-and-fill of soils, making use of the most of the complicated topography. As a result, the present land consists of many slopes, overpasses, and steep hills. As for community organization, the concept of the neighborhood-unit and disposition of housing contributed to the effective community development.
4. The transformation of the original terrain started in the areas characterized by the small relief features, low elevation, and low density of valleys. In terms of the direction of a slope, the intensity of housing development decreased in the land slanted toward the south where there was a good exposure to the sun and also in the land inclined toward the east, while it gradually increased in the shady slope with a northern exposure. The choice of land and the alteration of terrain advanced in the northwest and southwest sections where surface undulations were small, in the southeast where elevation was low, and in the south-west where there were fewer valleys.
5. The development of land that was formerly considered unsuitable for housing in terms of topographical conditions appeared at a later stage of the housing developments and could be seen in those areas adjacent to the already developed sections. The reason for this was that the high level of social conditions increased the pressure to develop further housing and resulted in quickening its pace, which in turn became the cause of developing the areas topographically unsuitable for housing.

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The purpose of this paper is to clarify the formative factors and the formative periods of beach ridge ranges formed parallel to the coastline on Holocene coastal plains in north-east Japan.
I. Factors forming beach ridge ranges were examined by tracing the past changes of sea-level and shoreline location during the last 6, 000 years at the area along the Abukuma river in Sendai coastal plain, located in the northeast of Honshu Island. Beach ridge ranges on this plain were divided into three on the surface. Beach ridge range I (BR-I), the innermost one, develops along the foot of hilly-land, about 4_??_6km far from the present coastline. Beach ridge range II (BR-II) lies between BR-I and beach ridge range III (BR-III) which is located along the present coastline.
Geological sections were obtained at four sites along the Abukuma river in Sendai coastal plain (Fig. 2):
Site (1) is located about 2.5km landward from BR-I. The past shoreline had been changing along the boundary line (broken line) between marine and terrestrial sediments in this geological section (Fig. 3-a). The sea-level had gradually risen from -5m to -2m, reaching the level about -3m at about 5, 600 y. B. P..
Site (2) is located on the landward slope of BR-I. The geological section is shown in Fig. 3-b. At this location the sea-level is estimated at about +1m from the upper level of brakish shells such as Corbicula japonica and Crassostrea gigas. The estimated age is 4, 470±120 y. B. P. from Corbicula japonica.
Site (3) is located between BR-I and BR-II (see Fig. 2), and the geological section is shown in Fig. 3-c. The shoreline migration is restored by the broken line in Fig. 3-c, utilizing the result of grain size analysis of aeolian and shallow marine sands in the present coastal area (Matsumoto, 1983). At this location, the sea-level had dropped from the level +1m shown at Site (2) to about -4m, and afterwards, the sea-level had gradually risen. The shoreline had proceeded toward BR-II. A slight retrogradation and a temporal sea-level rise were recognized near the center of this section. By this temporal rise of sea-level, a subsurface beach ridge range (BR-I') was formed.
Site (4) is located across the BR-II. The broken line in the geological section (Fig. 3-d) shows the migration of past shoreline; the shoreline position was also restored by utilizing the result of grain size analysis. The sea-level had reached the highest level in this section -1m just below BR-II.
The past shoreline migration through the last 6, 000 years was restored as the broken line in Fig. 5. The upper surface of sandy layer composed of both aeolian and shallow marine sands was undulated, corresponding to the multiple sea-level fluctuations. The beach materials at high level deposited corresponding to each peak of sea-level rise were recognized as beach ridge ranges on the surface of coastal plain. In this case (Fig. 5), four beach ridge ranges, including the subsurface one, i.e., BR-I, BR-I', BR-II and BR-III were built corresponding to the sea-level fluctuation. II. The developmental stages of each beach ridge range were examined on the basis of the examples of Sendai, Akita (South of Hachiro-gata), Ishinomaki, Tanabu and Aomori coastal plains. Four or three beach ridge ranges are commonly recognized on these coastal plains. Formative periods were estimated in each coastal plain by C-14 dating of samples collected from the bottom sediment of swales and shallow marine deposits.
As a result, the simularity in formative period of each beach ridge range was recognized (see Fig. 13). BR-I, BR-I', BR-II and BR-III were built respectively in the periods of 5000_??_4, 500y. B. P., 3, 300_??_3, 000 y. B. P., 2, 800_??_1, 600 y. B. P. And 800 y. B. P. _??_present.

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Mt. Tairappyo (1, 983m) is a snowy mountain against which the strong winter monsoon blows from the Sea of Japan. Gentle slopes are dominant in this mountain. Due to much snow, tall trees which usually form subalpine conifer forest are not able to grow on the upper part above 1, 600m. Therefore, no subalpine zone exists in this mountain. Instead of tall trees there excel meadows, Sasa fields or scrubs. The result of soil survey in this area showed that the buried peat is widely distributed under the Sasa fields or Graminea-herb meadows. The peat layers are 20_??_30cm thick and are buried under the Kuroboku (Ando) soil or alpine meadow soil (wet type), both with a thickness of about 15cm.
The accumulation of the present peat is limited at the bottom of nivation hollows. In these hollows snow patches exist till late June or middle July and supply enough melt water. The wide distribution of the buried peat layer indicates that there was an age when the remaining snow existed more widely in summer season as compared with the present. It seems that the delay of the snow melting is due to first the cool climate in that age. Perhaps it was low temperature at that age, especially in summer season. However, that age seems also to have had a heavier snowfall than the present situation. At present heavy snowfall occurs only in the year when the special strong cold waves hit Japan; it occurs in every ten and odd years. At the age when the buried peat layer was formed due to low temperature in winter, the frequency of the heavy snowfall must have increased, so that much snow existed comparing to the present. The buried peat layers probably accumulated owing to the delay of the snow melting caused by the increase of winter snow and the low temperature in summer. The ¹⁴C age of the bottom of the buried peat layer was 3, 100 y. B. P., suggesting that this cool and snowy age would correspond to the Neoglaciation.

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