The Mongolian and Chichibu geosynclines were confluent with each other at the Touman-Suifung area and the intrageosynclinal vulcanism was there repeated during the Palaeozoic era. In the older Mesozoic age the Songnim and Akiyoshi folded mountains in North Korea and in the continental side of Japan respectively were probably on the same line and not very far from the Sikhota Alin. Following the late Jurassic Daebo orogeny in the Ogcheon zone, the Yoshimo embayment was brought to being on the east side of the Korean peninsula. Subsequently the Tsushima basin was produced on the southeast side of the Yongnam land. The folded mountains of W est Japan in the Wealden Oga phase were probably on the east side of the basin. Later the Tsushima basin was destructed and still later the Miocene sea flooded into the hinter basin of the Sakawa folded mountains. The amount of the shifting of the islands arc of Japan since the late Cretaceous period was lessened in West Japan than North Japan. In my “Sakawa Cycle” of 1941, I attributed the difference of the shifting to the forelands i.e. subaqueous obstacles which are now often called oceanic plates.
Korean houses haven been classified, based on the regional styles of floorplan, into several types, such as the Northeastern type, Northwestern type, Central type, Southern type and Quelpart Island type, The Central type is prominent in the central part of Korean Peninsula including both Seoul and Gyeong-gi Province as its center and the Southern type spreads over the southern part, on the features and distribution of which nearly all studies have agreed. They have made clear that these two types have some common features such as a single-row-room plan with “daecheong” (a hall-like space with a board floor) in the center of the house. But they also indicate that the Central type has basically an L-shaped plan, while the Southern type has an I-shaped plan shunning a bended ridge, and that the open structure such as veranda, windows and doors are more frequently found in the latter. The distribution boundary between these two types has been regarded as running along the Charyeong Range (a range diverging from the Taebaek Range, the backbone of the Korean Peninsula, at the Mt. Odae, and running southwestward). The author did the field work in the central of the Charyeong Range, the border between Gyeong-gi Province and North Chung-cheong Province, and tried to clarify the features and distribution of the house types seen in this region, and also tried to find out if there is any relation between the house type and some other cultural factors, such as the terminology and the use of a room. In this paper, several findings observed during the course of this study are presented : 1. The so-called “Central type” houses are distributed everywhere in Seoul-Gyeong-gi Province area, and in some parts in the southern region of the Charyeong Range. However, in the piedmont of the southern edge of Gyeong-gi Province (northern piedmont of the Charyeong Range ; Yicheong and Yeoju counties), they begin to decrease in number, and in place of them, the I-shaped single-row-room type without “daecheong” becomes far more prominent. This type is fairly universally seen in all parts of the Korean Peninsula except Seoul-Gyeong-gi area and the northeastern mountainous part. I-shaped houses with “daecheong” are found, though not in so large a number, in North Chung-cheong Province, but it is in the region near the Sobaek Range (one of the branches of the Taebaek Range locating to the south of the Charyeong Range) that the typical Southern type becomes dominant. In brief, there is not a sudden and complete change of the type from the Central to the Southern one and their co-existence is not noticeable and, between these two types, there seems to be a third type which is an I-shaped house without “daecheong” and may be called a “General type”. 2. In Jeon-ra Province, it seems to be believed that a house with a bended roof ridge (L or U-shaped house) brings bad luck, but in the Central region, people seem to have preference for L or U-shaped house, and particularly in Seoul and its suburbs, it is popular to build L or U-shaped houses so as to enclose the courtyard. However, this style can be thought of as influenced by the urban culture. In the villages in Charyeong Range region, even L-shaped houses do not show the above-mentioned enclosing arrangement. 3. There are tow common names for a housewife's room in Korea ; one is “anbang” which means “inner room”, and the other is “Keunbang” meaning “big room”. These names do not necessarily reflect the actual position or size of the room, but there seems to be a regional differentiation in their use.