Showing papers in "The Quaternary Research (daiyonki-kenkyu) in 1974"

Paleoanthropology in Hokkaidô

Abstract: Recent archeological investigations in Hokkaido have shown that while the prehistoric culture in the southwestern part of the island was closely related with that in the northern part of Honshu throughout the Jomon and epi-Jomon Periods, those in the central and northeastern parts of the island comprised various elements quite alien from Japanese Jomon culture. In succeeding Satsumon Period and historic times, the cultures in Hokkaido have been relatively homogeneous, with the exception of the Okhotsk Coast area which was temporarily occupied by the Okhotsk Culture from the end of the epi-Jomon through the Satsumon Periods.Human skeletal remains excavated so far in Hokkaido were reviewed separately for the three prehistoric cultural areas: the southwestern, the northeastern and the Okhotsk areas. Those from the Jomon sites in the Southwest were found to be closely related in morphological features as well as in metric characteristics with the skeletal remains of the Jomon population in Honshu. Those from later periods in the Southwest, however, showed gradual change to a form more closely resembling the modern southwestern Ainu. On the other hand, the skeletal remains from the Northeast were found to have been very close morphologically to the modern northeastern Ainu since the beginning of the Jomon Period. Skeletal remains derived from the Okhotsk culture area, as represented by the Moyoro shell-heap materials, were found to resemble northern neighbours such as the Sakhalin Ainu, the Gilyak and the Ul'chi.It was tentatively concluded from the above findings and some distance analysis that the form of the Hokkaido Ainu proper was best represented by the modern Ainu in the northeastern part of the island exclusive of the Okhotsk Coast area.Craniological materials collected mainly from the northeastern part of the island by KOGANEI (1893) were analyzed by Mahalanobis' distance method for the purpose of seeking morphological proximity among fifty populations in northern Eurasia, Far East, Oceania, and North America. Among other things, unexpected resemblance was detected between the Ainu and the prehistoric human remains from Alati-Sayan highland in Siberia (ALEKSEEV, 1961). Further developments in archeology and paleoanthropology in Siberia and Hokkaido are needed before any conclusion can be drawn from this interesting finding.

Paleoclimatic Significance of Fossil Periglacial Phenomena in Hokkaidô, Northern Japan

Abstract: In present paper some fossil forms of frozen ground phenomena such as earth hummocks (Fig. 1), sorted patterned grounds (Figs. 3 & 4), festoon: vertical stones (Figs. 4 & 5), involutions (Figs. 7 & 8), and ice-wedge casts (Fig. 6) are described.The zonal distribution of active frozen ground phenomena and related environments are tabulated from some literatures as well as the results of our own survey on them in Japan (Table 1). Paleoclimate of the last glacial period in the esatern part of Hokkaido is considered after distribution of fossil frozen ground phenomena comparing with distribution of active ones. Volcanic ash layers and river terraces are surveyed to determine tephorochronologically the age of phenomena.The main results are as follows. All kinds of frozen ground phenomena, even earth hummocks, carry involution structures in cross section (Fig. 2). Stratified sediments such as volcanic ash layers clarify involution structures. In Japan, the southern limit of active earth hummocks coincedes approximately with +6°C mean annual isotherm. Therefore, buried earth hummocks and small-scale involutions do not indicate ancient cold climate in eastern Hokkaido where present mean annual temerature is nearly+6°C.Festoon, a kind of involution, can easily be found in fine sediments overlying river terrace gravels. Because of prevention of dense vegetation cover gravels do not reach the ground surface to form sorted patterned ground in most cases although some fossil sorted patterned grounds are found. Vegetation profited by warmth in summer sets the limit of sorted patterned grounds on nearly 0°C mean annual isotherm in central Japan and on a isotherm of somewhat lower than 0°C in Hokkaido.Some large-scale involutions (Fig. 8) may be cross sectios of palsas. Ice-wedge casts, indicators of ancient permafrost, are also found in the lowlands of eastern Hokkaido. Based on Pewe's observation decreasing of temperature at the time should be estimated as 12°-14°C.In this region ice-wedge casts indicating the maximum coldness are buried by a markable layer (Erimo Volcanic Sand: Spfa; 32, 200 14C yr.B.P.). It is, therefore, concluded from chronological studies of river terraces and volcanic ash layers that in this region the maximum decreasing of temperature precedes the maximum lowering of sea level observed all over the world in 18, 000-20, 000yr.B.P.

Permafrost at Mt. Taisetsu, Hokkaido and its Climatic Environment

Abstract: In this paper, the authors report the existence of permafrost at Mt. Taisetsu, Hokkaido, and disdiscuss the climatic significance of permafrost there from a viewpoint of the Quaternary palaecolimatology. Many researchers have observed that patterned grounds, especially sorted circles well developed on many gentle slopes and small depressions at Mt. Taisetsu. And recently it was reported that the networks of fissures of the ground which are similar to large scale ploygons on permafrost in Alaska were found at some places at Mt. Taisetsu. Those sorted circles and nets of fissures suggest the existence of permafrost which is believed to be either relict or recent.By our on-the-spot investigations at Mt. Taisetsu, permafrost was found on one of flat summits (2, 150m) by boring tests and geophysical methods. The maximum depth of the active layer was nearly 2m and the maximum depth of the lower limit of this permafrost was estimated to be 15m or larger. Its frozen soils consisted of weathered fine sands and gravels derived from an andesite bedrock, which are considered as frost-action products. Large sorted circles were form ed on the surface of permafrost.The mean annual temperature and degree-days in this area were calculated as -3.1°C and 2, 400 degree-days by extrapolations on the basis of meteorological data in Asahikawa. The estimated temperature and degree-days suggest that this area has the same climatic conditions as those in central Alasak, where discontinuous permafrost is distributed.Introducing the Popov's theory about the formation of an ice-wedge, we estimated the palaeo-temperature of the surface of the extended permafrost to be -7°--8°C (mean annual temperature) during a past colder period than present. Comparing the estimated chronology of the permafrost with the chronology of permafrost in Alaska and Siberia, and considering the field observations of fossil ice-wedge casts and polygons in Hokkaido, we may conclude that the permafrost at Mt. Taisetsu formed at the last ice age, after then gradually has become smaller, adapting itself to the present climatic conditions.

Littoral Molluscan Fauna of the Holocene Climatic Optimum (5, 000-6, 000y.B.P.) in Japan

Abstract: Six different types of molluscan assemblages are recognized in the Holocene littoral deposits, accumulated during the Climatic Optimum (5, 000-6, 000y. B. P.), along the Pacific coast of Japan. These assemblages are typically observed in the Holocene embayment deposits of the Paleo-Ohuna Bay in central Honshu (Lat. 35°N). They are found from several embayment deposits distributed between Okhotsk coast of northern Hokkaido (Lat. 45°N.) and western Kyushu (Lat. 33°N.), although their existence and local distribution within each embayment were controlled by topography of the bay and bottom sediments.The assemblages are composed mainly of the warm water species, intermixed with some cold water elements in the northern areas. The northern limits of the distribution of constituting species were located further north than those of the living species. The northward extension of distribution was remarkable in northern Hokkaido. Along the Okhotsk coast of northern Hokkido, the littoral molluscas, whose present day analogs are living in the area south of north Honshu (Lat 41°N.), were found constituting shell beds in the Holocene deposits, and also found from the shell mound in the Early Jomon era. In this area the minimum temperature of surface water at the Climatic Optimum was estimated to be about 5°C higher than at present when compared with the water temperature of northern Honshu. The southern end of the cold water species distribution is recognized in the Sendai area (Lat. 38°N.), where the warm water assemblages are intermixed with the cold water elements. Marine condition of this area was presumably similar to that observed at present in the area off Choshi, central Japan (Lat. 36°N.).The distribution of warm water species at the time of Climatic Optimum is shown in Figure 13. Estimated minimum surface temperatures are also shown in this figure. The temperature difference between the Climatic Optimum and the present becomes less conspicuous toward the south.

Some Palynological Notes on Grass Pollen, with Special Reference to Oryza sativa

Abstract: In order to examine the possibility of distinguishing rice pollen from other grasses, the sculptural details of 68 species including wild and cultivate type were studied based on the transmission electron (TEM) and phase contrast microphotographs (PCM).It was found that TEM of surface replicas might help the interpretation of phase contrast observations and might clarify the appreciation of differences in cases where a discrimination of the various types was difficult.Three types of grass pollen could be distinguished based on PCM.1. Punctate type: Grains have single spinules occurring one by one on the surface based on TEM. In this type each spinule appears as a distinct dark dot with phase contrast. Zea, Coix, Secale and sometimes Hordeum.2. Areolate (negative reticulate) type: More than three spinules appear grouped on small islands or clumps which are isolated by incised grooves based on TEM. Each spinule clump is seen as an irregularly delimited dark dot and their sculpture is areolate. Most wild grasses were studied.3. Maculate type: Mixed type of single spinules and clumps of two or three spinules. According to PCM, grains of this type are seen as indistinct punctate in lower focus but more or less indistinct areolate in upper focus. Oryza, Hordeum, Triticum and some Agropyron. Some of Bambusoidae such as Arundinaria, Chinobambusa and Sasa have grains of spinule clump type, but each clump is so small that it is seen as a indistinct dot and their sculpture is maculate.From this fact Oryza pollen can be distinguished from those of punctate and areolate types, but it is difficult to distinguish Oryza from other maculate pollen except for Hordeum and Triticum which have larger pollen than that of Oryza.

The Pleistocene Tephra in the Western and Southern Part of Tokachi Plain

Abstract: 1) 十勝平野西・南部に分布する洪積世の火山灰層は, 西方および北方に給源火山をもち, 多少とも粘土化の進んだ褐色～赤褐色の細粒～中粒火山灰層, 軽石質火山灰層, スコリア質火山灰層, 軽石層, スコリア層などからなっている. これを, 十勝ローム層と名付ける.2) 本地域の十勝ローム層は, 全層厚約10m, 比較的やわらかで, 軽石層に富む上部ローム層と, 上限にクラックが発達し, 固結の進んだ下部ローム層とに二分される.3) 下部ローム層は約3mの厚さをもち, 上更別II面と, これより高い地形面にのみ分布する. 上更別I面と, これより高い地形面では赤色を帯び,“古赤色土”状を呈する. 下部ローム層中には顕著な軽石層はみられない.4) 上部ローム層は約7mの厚さを持ち, 上札内II面と, これより高い地形面に分布する. 従来, 詳しい報告のあったE-a, Spfa 1, Spfa 2のほかに, 9枚の特徴的な軽石層, スコリア層を含む. それらは, 図1に示されている.5) これらの示標層のうち, RP IはHo, Mgに富み, oPx, cPxは少ない. その他の軽石層, TBSは, すべてoPx, cPx, Mgが主成分で, Hoは少ない. RP I, RP III, HP I～HP IVにはBioが, RP III, RP IV, HP IVには火山ガラスが含まれる.6) 上札内I面群を構成する厚い扇状地礫層に挾まれる示標層により, fill の時期が示される. すなわち, HP IVは fill の開始期, RP IV (OP) は fill の形成期の中頃, TBS～Spfa 1は fill の終了期を示す.7) TBSの供給源は調査地域の北方である可能性が強いが, その他の軽石層は, すべて西方の火山からもたらされたものと考えられる.8) 十勝団研 (1972a) のOp-1は, 筆者らの火山灰層序からみると, RP IIに対比される場合と, RP IVに対比される場合があり, Op-2, Op-3は, ともにRP IVに対比されることが多い.

World Climates in the Hypsithermal

Abstract: General northward displacement of all climatic zones in the Hypsithermal is infered from various field data from many parts of the World. This is consistent with my previous discussion on the Wurm climate done in the Bulletin of the Department of Geography, University of Tokyo, under the title “Climatic Zones in the Wurm Glacial Age” which appeared in 1971. The content of this report will appear in English also in the same Bulletin in March, 1975.

Zoogeographical Problems in Northern Japan

Abstract: BLAKISTON was the first who studied scientifically the distribution of mammals and birds in Hokkaido and in north-eastern part of the Main Land. He insisted from the zoological point of view that Hokkaido was once a part of Asiatic Continent. According to him Tsugaru Strait is an important line of demarcation of animal distribution in northern Japan (BLAKISTON, 1883). However, HATTA (1913) did not agree with BLAKISTON when he investigated Reptilian and Amphibian fauna of Sakhalin comparing with those of Hokkaido. For example the snake of Sakhalin is Vipera berus which occurs in northern part of Eurasian Contient while the snakes of Hokkaido are those which are very common in the Main Land. Therefore, he pointed that Soya Strait between Sakhalin and Hokkaido is zoogeographically more important than Tsugaru Strait.There has been a confusion concerning the origin of animals in northern Japan. Recently Salamandrella keyserlingii which is a continental salamander has been found in Hokkaido. The pika and continental lizard, Lacerta vivipara have been also captured in Hokkaido. From this HATTA's opinion seems to be denied. BLAKISTON did not mentioned why the deer and the raccoon dog which are inhabitants of the Main Land are found in Hokkaido.Recently paleontological as well as geological studies of Japan has been much advanced and it has been ascertained that in ancient glacial period either Soya Strait or Tsugaru Strait disappeared as a result of the lowering down of the sea level. Either BLAKISTON's theory or Hatta's opinion is recognizable when we take into account ancient geological changes of northern Japan.However, we shall pay attention to the migration of animals by means of drift ice which has sometimes brought the fox from Kurile to Hokkaido.

Various Patterns of Man's Adaptation to the Natural Environments in the Jomon Age

Abstract: Adaptation of Jomon people in the Japanese islands attained a certain level in the course of history between the stage 3 and 4 of Jomon Age which is divided into six stages.Cultural areas at that time can be divided into eight groups (see Fig. 1). These were I) Hokuto cultural area in the subarctic needle-leaf forest of eastern Hokkaido, II) Ento cultural area in the cool-temperate deciduous forest of southwestern Hokkaido and northern Tohoku, III) Daigi cultural area in the warm-temperate deciduous forest along the rias coast of southern Tohoku, IV) Ukishima-Otama cultural area in the evergreen broad-leaved forest of eastern Kanto where the coastal line was extensively elongated by the Jomon transgression, V) Umataka-Chojagahara cultural area in the warm-temperate deciduous forest on the Japan Sea slope where the winter snow is thickest in Honshu, VI) Katsusaka cultual area in the warm-temperate evergreen broad-leaved and deciduous forest on the Pacific slope, VII) Funamoto cultural area in the evergreen broad-leaved forest of western Japan and VIII) Sobata-Ataka cultural area in the evergreen broad-leaved forest of western Kyushu.Due to the adaptation to such natural environments these eight cultural areas showed great regional varieties. Locating in the northern side of the Blakiston line, Hokkaido had particularly different cultures. Differnt kinds of bears lived there and no wild pig was found. Accoridingly stone arrow-head showed larger percentage than stone spear-head increasingly in the north. Also the fishing cultures were different in Hokkaido where the cold ocean currents were dominant.In Honshu along which the warm ocean current were prevailing, Daigi cultural area was a center for fishery in ocean (fish-fook and harpoon for Chrysophrys major, Thunnus thynnus, Katsuwonus pelamis etc.) and Ukishima-Otamadai culural area was a center for fishery in bay (netsinker and bone fish-spear for Lateolabrax japonicus, Mylio macrocephalus etc.). Incipient agricultre is often discussed for the Katsusakac ultural area.Also wild nuts had regional differenciation. Nuts of Lepidobalanus were found from the cultures I)-VI), while those of Cyclobalanopsis and Passania were for the cultures IV)-VIII). Aesculus trubinata were common to II)-VI). Distribution of stone querns etc. had certain relationships with these nuts.The adaptation patterns, however, were quite complicated and it will take long time to reconstruct the whole adaptation systems. Cooperation with the related sciences is strongly needed.

Buried Forest on the River Bed of the Iwaki, in the Northeastern Part of Japan

Abstract: The alluvial plain of the Iwaki in the central part of the Tsugaru Plain is divided into terraces of two levels. The upper surface which was inferred to have been formed at the culmination of Postglacial rise of sea level in the early Jomon period, had been dissected, forming flat valley floors, which then were overlaid with sediments of the lower surface. Relics of forest, which grew on the former valley floors and were buried by the sediments of the lower surface, were discovered, being stripped its cover, on the river bed of the Iwaki. The species of the sampled tree was “Ulmus davidiana var. japonica”, being dated 2240±9014C years B.P. (GaK-4776). The forest was estimated to have grown during the period from the later half of the latest Jomon to the early Yayoi period of the Japanese neolithic age.From the above-mentioned, the following three stages can be recognized in the development of the alluvial plain; that is, an erosional stage of valley cutting before the latest Jomon period, a stable stage of forest-growing during the period from the later half of the latest Jomon to the early Yayoi period, and a sedimentary period of burying forest after the early Yayoi period.The stable stage in this area corresponds in age fairly well to the so-called low sea level stage in Hokuriku District and the cooler and moister period in northeastern Japan.

Accumulation Terraces of the Quaternary Ice Age in the Mountains of Central Japan

Abstract: The author has investigated three examples of accumulation terraces originated from Quaternary Ice Age at the upstream area in the high mountain in central Japan, namely at the River Yabusawa, Akaishi Mts., the River Gamata and the River Azusa, Hida Mts. These terraces are classified into two types. The first type is a dissected moraine or a dissected out wash which is situated in the proglacial site where the altitude continues to a cirque bottom. The second type which consists of a large quantity of sands and gravels is situated in the downstream to the site of the first type. The huge accumulation might have made by the overloaded stream having carried much detritus from the slopes above the timberline which had lowered during the Ice Age. The volume dimensions of the second type in round numbers are 100 times of the volcanic terrace and 1000 times of the earthflow terrace in the surrounding area. For the forming and retaining of the accumulation terrace a gorge might be needed in downstream site of the terrace acting as a dam. The former two examples have the both types of the terrace, and the latter has the first type only providing a vast alluvial valley flat being presumably a buried accumulation terrace.

Fluvio-geomorphic Changes during the Last Glacial Age in the main part of Hokkaidô, Japan

Abstract: Geomorphology of terraces and related features around Sapporo and several other districts in Hokkaido have been compared. The cause of geomorphic change in the last Glacial Age and its relation to climatic change are briefly discussed and reviewed.In that Age nearly same fluvial geomorphic changes occurred in these places. The large accumulation in the valley and piedmont region is found to have occurred once. Alluvial fan and aggradational terrace of the substage were already in dissectional phase at the time some what earlier than 30, 000 14C years B.P. The cause of the accumulation may be of climatic origin, but the correlation between climatic records and geomorphological events in these regions is not clear.

Present Status of Mammals of Hokkaido as Considered from That of Adjacent Territories

Abstract: From the study of fossils the present status of mammals in Japan is considered to have appeared since the Diluvian epoch of Quaternary. Most of the present mammals in Japan show close relation to those of the Asiatic Continent and the distribution pattern shows that there occurred animal interchange between the both areas in ancient times. Prototype of mammalian fauna of Hokkaido seems to have been constructed up to Post-glacier period after the isolation of Hokkaido from the neighbouring areas. At present, mammalian fauna of Hokkaido includes 19 sp. and 34 subsp. belonging to 34 genera, 14 families, 6 orders (see Table 1). The characteristic of mammalian fauna of Hokkaido is consisted in a mixed existence both of northern cold zone species and of southern temperate zone species including some great sphere ones. There are many marine animals which are rare in the Main Island. The existence of many northern cold species in Hokkaido and South-Kuriles shows close faunal relation to Sakhalin and Primorskii. Three genera of the vole, namely Clethrionomys, Aschizomys and Eothenomys; two species of the shrew, namely Sorex minutissimus and Sorex hosonoi; two species of the squirrel, namely Sciurus vulgaris and Sciurus lis; and two species of the hare, namely Lepus Brachyurus and Lepus timidus are very similar respectively in all aspects. However, no phylogenetic study of the animal has been made, though the matter is very interesting. The occurrence of Crocidura dsinezumi, Sorex minutissimus and Ochotona hyperborea in Hokkaido is particular. Their ecological and zoogeographical studies are necessary. More species of mammals in Kuriles may be added in future.

The Ainu and the Cold Climate

Abstract: The study of the language or foklore of the tribe may suggest what kind of the climate their ancestors experienced in the past. The author has tried to discover this from a study of the Ainu language and its oral tradition.The Ainu language, like English or Japanese, does not have many different morphemes for snow or ice when compared with Eskimo or Manchu. In some of “Yukar” legends of the Ainu, the serpent is thought to be a kind of taboo among the ancient Ainus. The snake was an alien creature, inhabiting no single category of the Ainu configuration of nature (sky, mountains, land, and water), but forever acrossing the boundaries between them.It is thus inferred that the ancient Ainus had some contact with snakes, animals that can hardly survive in the absence of a warm summer. From this we may venture to guess that the ancient Ainu people may have lived in a mild climate, or that the original Ainu culture might have dedeveloped in a land with a snowy winter and a warm summer. Ice and icebergs were not a feature of their world. The regions which the Ainus inhabited were sub-frigid at their coldest and there is no evidence that the Ainus had come from a very cold land such as the arctic regions.

The Ancient Sand Dunes in the Plain to the Southeast of Lake Mashu, Hokkaido

Abstract: A number of ancient sand dunes are developed in the plain to the southeast of Lake Mashu. The plain is also covered with thick layers of volcanic ejecta derived from the Mashu Volcano. Two layers of ancient dune sand are recognized; one is above the layer of Kamuinupuri-a volcanic ejecta and the other above the layer of Mashu-f volcanic ejecta. Very few investigations have been made about the origin of these sand dunes.After the investigations on volcanic ejecta, distribution of dunes, and mineralogical and mechanical compositions of dune sand, it is considered that the dunes consist of eolian deposits derived from channel deposits, consisting of coarse sand fraction of tephra sorted out by running water.

The Changing Climate through the Period of Meteorological Records and the Historical Past in Japan and Some Conciderations about the Cold Climate in the Alluvial Epoch

Abstract: The Far East monsoon regime is a consequence of the interaction of both planetary and regional factors. When the westerlies over the Eastern Hemisphere are weak in winter, the stational trough of the planetary wave, which is located normally in the neighborhood of the Japanese islands, tends to retreat in the Japan Sea side, producing the monsoonal climate, that is to say, the lower air temperatures in the south-western Japan and more snowy winter in the Hokuriku District. On the contrary, when the westerlies become stronger, the trough moves across the Japan Island to the Pacific side, resulting the non-monsoonal winter climate, warm winter in the southwestern Japan, less snowy in the Hokuriku District and more rainy in the Pacific coast. In summer, the trough, which is normally located farther west in the Japan Sea, moves westwards or eastwards, corresponding to the weaker or stronger westerlies, and produces hot-dry summers or cool-rainy summers in Japan. In other words, the winter and summer monsoons in the Far East change their vigor in contrast with the intensity of the prevailing westerlies throughout the year, and this is the reasons why the cold-snowy (warm-less snowy) winters correspond to hot-dry (cool-rainy) summers, and the curve of 11-year running means of the annual means of wind speeds at the summit of Mt. Fuji (3782m) changes opposite to those of the annual amplitude of air temperatures at various points in the central Japan.Through the rhythm of the decade means of summer air temperatures in the north-eastern Japan and the running means of the amount of January precipitations on the Japan Sea coast, a significant trend of long-term change is noticable, which must be attributed to the north-southward displacement of the climatic zone. The northward shift or the southward retreat of the climatic zone generally appears in company with the weak or vigorous state of the prevailing westerlies.Consequently, in the case of Japanese climate, the effect of the Far East monsoons on the winter climate, for instance, the lowering or rising air temperatures due to the change of the Far East monsoon, objects to the effect influenced by the north-southward displacement of climatic zone, while, in summer, both effects cooperate with each other.However, in the estreme cases of the displacement of the climatic zone, the global effect exceeds the regional effect of the Far East monsoons, producing the extreme case of“Little Climatic Optimum” with warm-less snowy winters and hot-dry summers and the extreme case of“Little Ice Age”with cold-snowy winters and cool-rainy summers.It is beyond question that the most favorable condition for the accumulation of snow and ice must be the extreme case of“Little Ice Age”distinguished with much snowfalls, lower air temperature in all seasons, and rainy summers associated by the reduced durations of sunshine. The climate in the first half of XV Century, for instance, is estimated to be the extreme case of“Little Ice Age”from the various records of decuments. In accord with the estimation, the 14C dating test on the wood which was discovered by Horie (1968) in the outwash deposit of Shirouma Kitamata (1620M) gives 520±80 years B. P. Howeve, the duration of extreme period of“Little Ice Age”is not so long as far as it concerns within historical times. The climate of (warm-winter)-(cool-summer), which is caused by the predominant westerlies and distinguished with the intensified activities of Lows in the surroundings of the Japan Island, is also favorable, to a certain exextent, for the accumulation of snow.

Climate of Glacial Period

Abstract: We may say that the terrestrial climate has been rather unstable during the period since the beginning of Quaternary up to the present. The so-called Milankovitch's solar curve basing on his summer curve has been used by many researchers in order to explain the Quaternary glacial and interglacial alternation.His another curve, the winter curve, suggests a latitudinal insolation difference which brings about a change of latitudinal temperature gradient in winter as in the case of summer. Therefore, the change of winter atmospheric circulation may possibly create a new glacial or interglacial period, though he did not mention such circulation regime. The minimum temperature period showed in his summer-half-year solar curve corresponds to the greatest temperature gradient in his winter curve at the middle and the high latitudes in northern hemisphere. If a meridional circulation type previals in winter, precipitation and temperature patterns in northern hemisphere become favorable to form new continental glaciers in the specified regions.The author has criticized these considerations with the view point of recent researches concerning the global radiation, the atmospheric general circulation and also the meteorological events.