Sericulture/filature was a leading industry to contribute to Japanese economy in early twenty century. Silk mills have a key role of yarn reeling process and produce high quality silk from cocoon. Gunma Prefecture is called as a “Silk Country” resulting from both cocoon and raw silk production amount. Tomioka Silk Mill in Gu nma was inscribed as a World Cultural Heritage as the presence of reeling technologies. Most of the mills was closed during World War II, but after the war over 30 mills was quickly recovered with domestic market demands. However, the business was slowing down again due to business recession after oil shock and cheaper imported silk. The silk mills shut down year by year and at present only one silk mill is operating. The objectives of this research are to clarify (1) location of the mills, (2) current util ization of the sites, and (3) outcomes from the historical background of the mills. There are five kinds of the site utilization – public facilities, commercial complex, housing district, factories and open space. The major business owners tend to maintain the sites in case but mostly it is not easy to define a trace of silk mills there.

抄録全体を表示

脊梁山脈中央部に位置する鬼首カルデラを起源とする中期更新世テフラ層として,鬼首池月テフラ層(O-Ik:約250ka)がある.O-Ikは,火砕流堆積物を主体とする総体積18～36km³のテフラ層で,脊梁山脈東山麓側の宮城県北部丘陵地域に分布する最大規模のテフラ層として広く認められてきた.一方,脊梁山脈西山麓の・新庄盆地では,山屋層と呼ばれる厚い砂礫層の中および上位の層準に,火砕流堆積物が認められてきたものの,他地域のテフラとの対比がなされていなかった.本稿では,・新庄盆地に分布するテフラ層中の火山ガラスや斜方輝石の屈折率測定,および火山ガラスの主成分化学組成の分析から,同地域においてもO-Ikが分布することを明らかにした.この新たな知見により,新庄盆地南部に分布する舟形断層・長者原断層など構造線の活動場の変化と,それに伴う丘陵内の高度分化を時系列的に明らかにできた.さらに,脊梁山脈を挾んだ東西山麓地域での中期更新世以降の地殻変動と地形発達様式に差があることが明らかになった.

抄録全体を表示

Technologically considered, the hand-reeling silk industry was not fit for large-scale cooperation. Tengensha, in Maebashi, Gumma Prefecture, was classified as a large workshop in the official statistics. But, if wa examine it making use of records of the firm, it is clear that only the finishing process was done there, and Tengensha was nothing but a putter-out. We can find out many examples of such concentration of finishing process only, if we examine statistics carefully: the hand-reeling industry did not develop into large-scale factory production. The hand-reeling industry was ousted by reeling by machine in the Taisho era, though it survived to the end Meiji, taking advantage of its co-existence with the landlordism.

抄録全体を表示

地すべりなどのマスムーブメントは,山地地域の地形発達に大きな役割を果たしている.小論は,山地の地形発達を明らかにする観点から,山形県白鷹火山中腹および蔵王火山北西山麓に残る巨大山体崩壊起源の地形について,それらの移動・堆積域に発達する凹地・湖沼堆積物を採取した.そして,それら堆積物中のテフラの対比から,初生的なマスムーブメントの開始時期を明らかにした.白鷹・荒沼堆積物からは12層,蔵王・酢川泥流による閉塞で発達した旧久保手湖堆積物からは,2層の後期更新世テフラが見いだされた.荒沼堆積物最下部からは,岩屑流堆積物を覆ってOn-Ng(ca.80ka)が発見された.旧久保手湖堆積物の中部および下部層からは,Ad-N1およびNm-Knが発見された.これらのテフラ層から,白鷹火山の崩壊にともなう荒沼の形成は,遅くともMIS 5の前半に起こったものと考えられる.旧久保手湖は,堆積物の厚さと堆積速度から外挿して,MIS 4はじめに形成されたと考えられる.

抄録全体を表示

It was an urgent neccessity for Japan, which started its industrialization much later than the western countries, to develop traditional industries, in order to catch up with enlarging international trade. Above all, the government needed to increase the production of the silk industry because of the large demand for silk products by foreign contries. Money raising for the industry was a maior concern for the govenment which established the Maebashi Dai Sanjo-ku Nationaal Bank in the Joshu district, the most important center for the silk industry since the later part of the Tokugawa period in order to satisfy capital needs. This article aims to make clear: (I) how the government tried to encourage the industry through the newly established national bank, (2) how the industry was reorganized and modernized by the government policy, (3) what kind of financial relations developed between the bank and industry.

抄録全体を表示

The eruptive history of the Higashi Izu monogenetic volcano field for the past 32,000 years is revealed by tephrochronology and loess-chronometry. Morphology, color, and size of basaltic tephra grains are widely variable depending on the mode of the eruption; e.g., spinose red scoria are fallout from a strombolian eruption column when a scoria cone is established around the crater; yellowish green lapilli and hard tuff (kata) are products from phreatomagmatic explosions, the former being more magmatic than the latter. In the field, these discriminations are useful not only for identification of each tephra bed, but also for understanding the transition of eruptive styles during one eruptive event. Because vents are closed or sealed at the end of an eruption, an absolutely quiescence occurs between eruptive events in a monogenetic volcano field. This proves the validity of loess-chronometry. Some of the NW-SE or NE-SW trending alignments of volcanoes proved to be created by eruptive fissures; i.e., they are erupted simultaneously. Among them, the 11 km-long Iwanoyama-Iyuzan volcanic chain is the most conspicuous, which was active about 2,000 years ago. Eruptive events more than 10⁹ kg of magma discharge are recognized 13 times during the past 32,000 years, so that the average frequency of eruption in this field is calculated one every 2,500 years. The last is the Iwanoyama-Iyuzan eruption. The discharge rate of magma is 100×l0⁹ kg/ky for the past 32,000 years or 330×10⁹ kg/ky for the past 5,000 years. The rate seems to be accelerated recently, however, it is still an order of magnitude lower than that of a polygenetic volcano such as Izu Oshima. The Kawagodaira eruption of 3,000 years ago is remarkable for two reasons: the largest with 765×10⁹ kg of magma and the first appearance of rhyolite in the field.

抄録全体を表示