PALEOENVIRONMENT OF JAPAN IN THE RECENT 500,000 YEARS,BASED ON AMINO ACID ANALYSIS

该项目是根据日本中-晚更新世海洋沉积物中的软体动物样品的氨基酸分析和ESR（电子自旋共振）测年进行的;太平洋一侧的本班海岸和三浦半岛，以及日本海一侧的大贺半岛和诺托半岛。常磐海岸的牡蛎样品保存不好，不适合分析。结果如下：1.建立了氨基酸分析系统，从样品计数到数据处理的自动化程序大约需要30分钟。2.三浦半岛和大贺半岛的ESR测年结果支持了裂变径迹法和岩石年代学的年代学结果。只有诺托半岛的年代表明，倒数第二次间冰期距今200 ka。这表明地壳垂直运动的速率应重新研究。3.氨基酸分析的相对年龄支持ESR年龄几乎是肯定的。异亮氨酸的D/L比值表明，成岩作用中北方软体动物的消旋速率比南方慢，且在单位至间冰期内的消旋速率是一致的。根据这些数据，气候温差估计与最近的大贺-诺托半岛-三浦半岛之间一样均匀。

This project was performed based of amino acid analysis and ESR (electron spin resonance) dating of molluscan samples derived from the middle -late Pleistocene marine sediments in Japan ; Jaban Coast and the Miura Peninsula on Pacific Ocean side, and the Oga Peninsula and the Noto Peninsula on Japan Sea side. The oyster sample from Joban Coast was not suitable for analysis with bad preservation. The results are as follows.1.Amino acid analysis system was set up with automatic routine requiring about thirty minutes from counting to data processing for a sample. This system made repeated runs with less error possible.2.ESR dates fromthe Miura Peninsula and the Oga Peninsula support previous age estimated by fission track dating or thephrochronology. Only the date from the Noto Peninsula suggest the penultimate interglacial stage 200ka ago. This indicates that vertical crustal movements should be re-examined in rate.3.Relative age estimated from amino acid analysis supported that ESR dates are almost sure. D/L ratio of isoleucine shows that racemization rate in more northern mollusca is slower than in southern ones in diagenesis and the rate is uniform in unit to interglacial. Based on these data, the climatological temperature difference is estimated to be as uniform as the recent between the Oga -the Noto Peninsula -the Miura Peninsula.