@article{oai:niigata-u.repo.nii.ac.jp:00028224, author = {藤田, 至則 and 宮城, 一男 and 松山, 力 and 木村, 千恵子}, journal = {新潟大学積雪地域災害研究センター研究年報, 新潟大学積雪地域災害研究センター研究年報}, month = {Mar}, note = {The Japan Petroleum Development Cooperation is planning to construct a petro-chemical complex in the northwest of Takahokonuma of the Shimokita Peninsula, Aomori Prefecture. In the south of the projected site, a tectonic valley is inferred to extend from about 4krn of south of it, running in a north-south direction (1:50,000 Geological Map of Hiranuma, 1970). On the other hand, in the northern area, from about 4km north-northeast of the site, a fault of a north-northeast trend is developed (1:50,000 Geological Map of Mutsu-Yokohama, 1970). The present writers assumed that the tectonic valley could be an active fault of a young age, and investigated the geology of the tectonic valley and surrounding areas. As a result, the following conclusion has been reached. The faults developed in the vicinity of the tectonic valley are collapse-type faults that were formed just prior to the deposition of the Shimosueyoshi loam and before the deposition of the Tachikawa loam (from 140,000 to 13,000 years ago), and most of these active faults are normal faults. The throw of these faults does not seem to be very large, and as they are mostly normal faults the scale of faulting may not have been large relatively. Although they belong undoubtedly to the category of active fault, their formative period is still a question. It is uncertain whether or not they were formed in the Late Pleistocene period, the age which requires special attention according to many researchers. After all, it is desired to investigate the faults minutely and work out a measure to meet the situation. Excavation would be an appropriate way to know if these faults are developed under the base. In this paper the writers present their doubts about the investigations on the active faults hidden underground or in the areas lacking in Quaternary formations. The writers also express their views against the common saying that a too strict definition of active fault in such a country as Japan would impede the engineering plans, and also against some intellectual persons who comment that Japanese geologists should make more efforts to popularize the concept of active fault among the less-informed general public.}, pages = {9--23}, title = {「むつ小川原・石油備蓄基地建設予定地」における"活断層"問題 : とくに,"島弧変動論"の立場から}, volume = {2}, year = {1980} }