宮城県中部の

に位置する森林公園において，地形地質および里山利用をテーマとした市民向け自然観察会を開催した。周辺地域も含めた丘陵の地形地質と地史，過去の里山利用とそれに関わる景観などを観察し，参加者にはおおむね好評であった。内容のさらなる工夫を図りつつ，地学的自然や里山利用をテーマに継続的に観察会を企画していくことは，研究成果の社会発信として重要と考えられる。

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The author studied the river terraces and the gentle slopes along the Yoshida River which has its source in the Ou mountain range, and runs through the Yoshida Lowland situated in the northern part of Miyagi Prefecture. The following results are obtained.
1) Geomorphological surfaces along the river and in the hill-land to the north of the river are subdidived, from the upper to the lower, into Yoshioka I and Yoshikoka II Surfaces, Warimae, Yoshida and Omori Surfaces, and the Alluvial Plain.
2) Yoshioka Terrace by R. Tayama (1933) is subdivided into two, namely, Yoshioka I and Yoshioka II Surfaces. Yoshioka I Surface is an erosion surface and contemporaneous with the river terrace Yoshioka II Surface in its formation.
3) Yoshida Terrace by R. Tayama (1933) comprises the river terrace Yoshida Surface and a gentle erosion surface Warimae Surface along valley sides. At the time of the formation of the Warimae Surface, shallow valleys developed at the heads of the tributaries in the hill.
4) The characteristics of Omori Surface is similar to that of Warimae and is limited in a certain part of the hill in its distribution. Yoshida Surface does not exist in the part. From such a fact, concerning the nature of Alluvial Plain deposits and the characteristics of the morphology of the hill top, the author concludes that the tectonic line through the Niibori valley is efficient to the development of Surfaces. He calls the line the Omatsuzawa Tectonic Line.
5) Gentle slope Warimae Surface and shallow valleys are formed after the red weathering of the hill rocks, at the time of low sea level. Granted that the red weathering happened during a warmer stage, the surface must have been formed in a glacial stage.
The development of the surface is dependent on the direction of valley, so he thinks that tectonic as well as climatic effects were influential on its formation, though he can't differentiate the two.
Geological structure of the hill influenced the profile of the gentle slopes, namely, some profiles have knicks and others do not.

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Based on detailed observation of slope form and regolith characteristics, this paper discusses the spatial changes of slope processes and their differences in intensity and frequency on both segments seperated by the lower convex break of slope in a small watershed in the Omatsuzawa Hills. The detailed observation of slope morphology and grain-size analysis of regolith reveal that slope processes are prevalent both on the upper and that lower slope segments in the recent past and more frequent and intensive slope processes were prevailed on the lower slope segment. The lower convex break of slope designated as the Postglacial Dissection Front is a result of more active erosion on the segment lower than the break, but it does not mean non-occurrences of slope processes on the segment upper than the break.

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過去の人為作用の中には地表面の改変（地形変化）を伴うものがあり、その結果として独特の人工地形や構造物が作られたり、人為に誘発された加速的地形変化が生じたりすることもあった。二次植生等の植生景観に比べ、このような人為作用の地形的痕跡への認知度は低いように思われる。しかしこうした地形現象を認定・記載することは、丘陵地の環境変遷や景観の成立に過去の人為作用がはたした役割を評価する上で重要であり、本発表では仙台周辺の丘陵地において演者らがこれまでに記録した人為の痕跡としての微細地形について報告する。具体的には、仙台市北方の

にみられる炭窯跡、仙台市青葉山の亜炭鉱跡に関係する人工地形及び多量の亜炭片を含む表層堆積物を事例に、それらの特徴から推定される過去の人為作用の特徴や環境変化（荒廃）について考察する。

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酒造業界も年々厳しさを増し所謂千石酒麗にとっては頭の蒲いところである。窮状打開策の一つとして企業合同があるが, そのやり方にも色々な方式があろう。気の合った若い経営者が相集い研究を霊ねた結果,「観光コース」開発の構成要員としての酒蔵という新機軸を打ち出した。未だ軌道に乗ったとはいい難いが, 一つの新構想としてここに取り上げた次第である。その設立経過, 抱負などには大方の参考になる点があるのではなかろうか。

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Around the coastal Plains in Japan, there spread the undulating low hills cutting the unconsolidated Tertiary sediments, some of which were once considered as “low level peneplains”.
The application of Hack's (1960) dynamic equilibrium concept will explain the origin of the accordant summits of the hills, if the extent and relief of the erosionally graded landscape on geological varieties is evaluated.
When the original flat surface was dissected based on the slightly lower baselevel in the Quaternary baselevel fluctuation, as the author previously reported, an accordant erosional surface is formed in a limited height zone between the two. Although it is akin to “partial peneplain” or “old-from-birth peneplain”, it is not “almost a plain land”, but it presents “ridge and ravine topography” proposed by Hack (1960) or “mixed stage topography” by Nishimura (1963).
The author reviewed the relief and extent of the erosionally graded landscape which is rock-controlled or controlled by local baselevel in the Appalachian, the Piedmont peneplain lands and some elevated peneplains in Japan, from the reports treating the peneplain.
The valley depths of the two types in hills are recorded; the wide and shallow “high level valley” (Nakamura 1963) acting in denudation on the hilltops, and V-shaped valley cutting down the former and analysing the hills. Both types of valleys are in mutual relation as the latter is nourished by the former. It is concluded that in the case of slight baselevel drop there appear only the shallow valleys, which make the undulating hill landscapes.

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In Japan most of the coastal plains are originated from the sedimentary basin of the Neogene formations. Three types of formation process have been reported to explain the accordant level of the hills around the coastal plain;
Type A: When the terrace surface of the soft rocks around the coastal plain is cut controled by the next, slightly lower baselevel, the undulating surface is made as a state of dynamic equilibrium of the unconsolidated materials.
Type B: At the thinner soft rocks around the sedimentary basin, the basement of the soft rocks reappears as undulating surface without any baselevel control.
Type C: The undulating surface emerged in early Pleistocene and subjected to erosion under the baselevel control till the formation of the Higher Terrace.
The types A and P have been reported by the author with the examples in the Kitakami valley plain, Tohoku, and in the Muroto peninsula, Shikoku. The type C has been reported by others to explain the so-called “Setouchi Surface” along the Japan inland sea.
The erosion surface of the northern Awaji island reported in this paper is correlated with the “Setouchi Surface”. The undulating surface on the horst corresponds to the basement of Miocene and Upper Pliocene sedimentary rocks on the granite bedrock. Judging from the development of paleo red soil with 10R hue, it becomes clear that this erosion surface had been formed before the Higher Terrace stage. The surface had not been covered with any sea level during the Higher Terrace stage nor with the Lower Pleistocene member of the Osaka Group.
So-called “Setouchi Surface” may have various origins and formation processes in each tectonic location. The type E is also suggestive for the explanation of the lower peneplain in the Chugoku mountains.

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Undulating erosion surfaces were developed in the basins of the southwest piedmont of the Kitakami mountains. These basins are located along the east tributaries of the Kitakami river, i. e. Miyamori basin along the Sarugaishi river, Yanagawa and Hirose basins along the Hirose river, Maisato basin along the Hitokabe river, Ohara and Surisawa basins along the Satetsu river and Senmaya basin along the Senmaya river. They were formed in several rows under structural control and most are located on exposed granites intruding into Paleozoic rocks.
Undulating erosion surfaces in the basins are mostly less than 300m a. s. l. in height. The original forms of the basins are outlined before the deposition of upper Pliocene fluvial deposits, which are distributed widely along the Kitakami valley and its tributaries (Fig. 1). The fill top levels of Pliocene fluvial deposits are identified at 200 to 300m a. s. l. in most basins, and their levels are well explicable for each height of superposition by the rivers (mark in Fig. 1).
Underlying geology of the undulating erosion surfaces is thick unconsolidated Pliocene gravel bed in Miyamori, Hirose basins and northern half of Surisawa basin, and weathered granites in Yanagawa, Senmaya basins and southern half of Surisawa basin. However, patches of very thin Pliocene gravel bed remain along the ridge and the valley floor of the undulating erosion surface in the Yanagawa basin (Fig. 2).
The level of Senmaya basin is low enough to be drowned in Pliocene base level, though the Pliocene bed is not seen presently. The level of undulating erosion surface in the southern half of Surisawa basin, most of which underlain by granites with the exception of the lower part by a thin Pliocene bed, is lower than the top of the Pliocene bed in the northern half of Surisawa basin.
The base level in the periods of middle and late Pleistocene in the upstream basins is estimated only some ten meters lower than the top of the Pliocene beds. The base level in the upstream basins at the 140m terrace stage along the Kitakami main trunk is calculated to be at less than 100m below the top of the Pliocene beds in most basins (Tab. 1). The highest base level during middle and late Pleistocene is some ten meters higher than the 140m terrace along the Kitakami main river.
The Pliocene bed, therefore, was not removed in the duration of the earlier half of Quaternary, though it was not very thick originally. The formation of erosion surfaces in the basins is, at the latest, after middle and late Pleistocene, and it is not be said that the erosion surface controlled; by a long stable base level, but it is a rock- and base level-controlled topography which is a dynamic equilibrium of soft rocks under the condition of small potential height above the base level of erosion.
Deep weathering of granites under the undulating erosion surface may have occurred after the resurrection of the base form of Pliocene beds as their restored base form suggests the effect of selective erosion between Pliocene beds and granites.
Assuming that the undulating erosion surface on the mountain tops higher than 500m is a remnant of a peneplain, they are older than Pliocene because Pliocene beds are distributed lower than 400m a. s. l. in the level mentioned above, they are contemporary or older than Miocene because Miocene andesite, the basal member of the Green Tuff Group, is lower than 500m in the western piedmont of Kitakami mountains.

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2011年東北地方太平洋沖地震における宮城県中部地域の地盤災害を，現地踏査の結果を基に紹介する。対象地域は，鳴瀬川水系（鳴瀬川，吉田川）の堤防被害，内陸低地部の被害である。堤防被害では噴砂は堤内畑地，堤外高水敷，堤防法尻に現れ，前2者は旧河道などの埋戻し，後者は堤体材料の液状化が原因と考えられる。このうち堤体が液状化したところは大きな崩壊につながったものもあった。低地では，大崎市古川駅周辺，鹿島台，多賀城市などで噴砂が現れたが，いずれも局所的なもので，被害も大きくは無かった。造成，埋立てなどの地盤改変地帯で液状化が起こったと考えられる。このほか，海岸地域でも液状化が発生していたと考えられるが，その後の津波のため，小数の事例を除き，その発生を確認することはできない。全体として液状化による地盤変状に伴う被害が多かった。

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仙台周辺の丘陵地のうち,西田中地区について,谷頭部の地形・地質調査を行ない,谷の構造・発達過程を明らかにした.西田中地区の谷すじは,上流から谷頭部・V字谷・谷底平坦面を有する谷に分類され,特に谷頭部は大規模平底型・杓子型・小規模平底型に細分された.
大規模平底型は,第II段丘面形成後,埋積第III段丘形成中(約6～3万年前)に形成されたと考えられる.この時期はヴュルムの最寒冷期に向かう時にあたる.間氷期を経て風化が進んだ地表付近では,風化した第I段丘構成礫や大年寺層に,湿潤・寒冷の気候下で数万m³の地すべり性斜面崩壊が発生した.この崩壊によって大規模平底型谷頭部が形成され,その時の移動物質はV字谷などを埋積した.また,第II段丘面上の一部には堆積性の緩斜面を形成した.
杓子型谷頭部では,30,000年以降,現在まで谷頭浸食を続けている.このタイプの谷頭を形成した原因は,基盤岩の節理やパイプネットワーク(Whipkey, 1965)をすべり面として発生した数千m³の斜面崩壊と考えられる.
小規模平底型谷頭部は,大規模平底型谷頭部の谷壁斜面～谷頭凹地に発生した1回性の地すべりによって形成された.これらの谷頭の発達を大局的に支配するものは浸食基準面の変化である.

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In the course of study of hill landform, it seems necessary to investigate not only the initial surface of the hill which is shown as accordant-height summits and is conceived to indicate a baselevel of erosion in an earlier age, but the processes of destruction or modification from initial surface into the present relief, the processes suggested, in the shapes of present valleys and slopes.
In the hilly land shown in Fig. 1, situated to the south of Sendai, there are two levels of accordant-height summits, H_I and H_II Levels. The Levels cut the Miocene Formation in the major part, and, in the minor part H_I Level is underlain with weathered round gravel bed of the middle or lower Pleistocene. Above the summits of H_I and H_II Levels, protrude some peaks grouped into H_I. Theose Levels are surrounded by a lowlying hill surface, H_III originated from the denudation surface formed prior to the fall of Yellow Pumice. Characteristic gentle slopes and shallow valleys were formed over whole area shown in Fig. 1, when the T_I terrace formation proceeded. That terrace is correlated to the last low sea level by NAKAGAWA et al. (1960). Those slopes and valleys are in the surface forms continuous not only to T_I but to the higher Levels especially to H_I and they cut Yellow Pumice Bed, Such landforms, judged from their geological and morphological features, seem to be mainly formed with a kind of mass-movement on the valley-sides. Gentle slopes here may be Cryopediment by WAKO (1963). Through the formation of such geomorphological elements, Coarsetexthred landscape (COTTON, 1963) was arranged over the whole area, later some parts are reduced into Fine-textured landscape (COTTON, op. cit.) through the V-shaped valley formation. The Coarse-textured landscape is preserved better where the local baselevel is high. Throughout those processes, geological structure has continuously influenced the lartdform development and certain tectonic, movements took place even after the formation of T_I surface.

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The distribution of large-scale mass movement in the central area of Ou Mountains including southern Rikuzen Hills, which has an area of over 1ha per one movement is surveyed. The relation between largescale mass movement and erosional processes of this area is studied. Results are as follows.
When this part is divided into three geomorphological unit—volcanic mountainland, non-volcanic mountainland and hilly land—, large-scale landslides are most conspicuous in the volcanic zone and least in the hilly area.
In the volcanic zone an desitic lava covers tuffaceous Tertiary basement, and large-scale landslides result from such a geological setting. Kuwanuma landslide (Fig. 3) is the largest, that has an area of 720ha. Generally speaking, this type of landslide is common to the old volcanoes with gentle surfaces covered by cap rock layer. This is a different pattern of volcanic dissection against the type of linear erosion seen on a new conide.
In the non-volcanic zone, the landslides are of rapid type and in small scale as compared with volcanic zone, and landslides occurred on the mountain slope in early mature stage.
In the hilly area most hills overlaid by resistant rock are dissected through the following processes—(1) linear erosion by stream into the flat hill-top surface, (2) occurrence of large-scale landslide, (3) stream erosion in the sliding mass, (4) occurrence of secondary landslide, (5) washing away of the sliding mass and linear erosion by stream in the surface of rupture, (6) formation of the dendritic ridge pattern. The landform development of Rikuzen Hills will be explained by application of the above-mentioned processes.

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