Paleoenvironmental Analysis of Siliceous Sediments in Relation to Opening of the Japan Sea

与日本海开口相关的硅质沉积物古环境分析

• 批准号: 01470053
• 负责人: IIJIMA Azuma
• 金额: $ 3.39万
• 依托单位: University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (B)
• 财政年份: 1989
• 资助国家: 日本
• 起止时间: 1989 至 1990
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-01470053/
• 关键词: Paleoenvironmental analysis; Opening of the Japan Sea; Siliceous sediments; C; S ratio of sediments; Tertiary Sedimentary basins; 古環境解析; 新第三紀; 堆積岩中の硫黄; 女川層; 東北日本

(1) We established analytical method to determine total sulfur content in marine sediments using a LECO-HF20 equipment. Measurements are seriously affected by a little amount of salts, particularly NaCl. It is, therefore, necessary to desalt the marine sediments before analyzing.(2) Total sulfur content (S) and total organic carbon content (C) in Neogene sediments of the Japan Sea, collected during ODP Leg 127, were analzsed. The C/S ratio of sediments reflects oxygen level in bottom water and it is about 3 in normal seawater sediments. The Leg 12 Neogene sediments show a wide range of the C/S ratio from 0.10 to 20. Late Miocene dark gray mudrocks have the minimum value of the C/S ratio, which indicates an anoxic environment due to isolation of the Japan Sea.(3) Quaternary sedimentary columns at sites 794, 795 and 797 is characterized by cyclic repetition of lighter-colored and darker-colored muddy sediments. The lighter-colored muds have larger values of the C/S ratio indicating oxyic environments. In contrast, the darker-colored muds show smaller values suggesting anoxyic conditions. This cyclicity accords with the cyclicity of Quaternary climatic change.(4) Evolution of Tertiary sedimentary basins in the circum-Japan Sea region with reference to opening of the Japan Sea is clarified on the basis of paleogeographical and paleobathymetrical maps of each interval from Eocene to latest Pliocene in age. The phenomena of the above items (2) and (3) can be interpreted by the evolution of the basins.

(1)利用LECO-HF20仪器建立了测定海洋沉积物中总硫含量的分析方法。测量受到少量盐分的严重影响，尤其是氯化钠。(2)对ODP127航次采集的日本海新近系沉积物中的总硫(S)和总有机碳(C)进行了分析。沉积物的C/S比值反映了底层水的含氧量，正常海水沉积物的C/S比值约为3。晚中新世深灰色泥岩的C/S值最小，表明日本海的隔离是缺氧环境。(3)第794、795和797点第四纪沉积柱具有浅色和深色泥质沉积旋回重复的特征。颜色较浅的泥浆具有较大的C/S比值，指示有氧环境。相比之下，颜色较深的泥浆显示出较小的值，表明存在缺氧条件。这种旋回性与第四纪气候变化的旋回性相一致。(4)根据始新世至上新世末期各时期的古地理和古地形图，阐明了环日本海地区第三纪沉积盆地的演化与日本海的开放。上述(2)和(3)项的现象可以用盆地演化来解释。

项目成果

Tada,Ryuji,Koizumi,I et al.: "Quaternary paleoceanography of Japan Sea from Site 797B,Leg 127" Initial Report of the Ocean Drilling Project. 127B. (1991)

Tada，Ryuji，Koizumi，I 等：“来自 Site 797B，Leg 127 的日本海第四纪古海洋学”海洋钻探项目的初步报告。

Tada,R.and Iijima,A.: "Revision of lithostratigraphy and compositional variation of Neogene hemipelagic sediments from Japan Sea" Initial Reports of Ocean Drilling project. 127/128. (1991)

Tada,R. 和 Iijima,A.：“日本海新近纪半远洋沉积物的岩石地层学和成分变化的修订”海洋钻探项目的初步报告。

Iijima,Azuma,Tada,Ryuji and Matsumoto,Ryo: "Sedimentary basins of the Tertiary strata of Japan related to the opening of Japan Sea" Journal of Faculty of Science,University of Tokyo Sec.II. 22. (1990)

饭岛东、多田龙二、松本亮：“与日本海开口有关的日本第三纪地层沉积盆地”，东京大学理学院学报第二期。

Matsumoto,Ryo: "Oxygen isotopic ratios of the interstitial waters from Sites 798 and 799,Leg 128" Initial Report of the Ocean Drilling Project. 128B. (1991)

Matsumoto,Ryo：“798 号和 799 号站点第 128 段间隙水的氧同位素比”海洋钻探项目的初步报告。

Tada,R.,Koizumi,I.,Brunner,C.,Cramp,A and Rahman,A.: "Correlation of dark and light cycles,and origin of cyclicity in Quaternary sediments from Sites 794,795,and 797" Initial Reports of Ocean Drilling Project. 127/128. (1991)

Tada,R.、Koizumi,I.、Brunner,C.、Cramp,A 和 Rahman,A.：“794,795 和 797 号地点第四纪沉积物中暗循环和光循环的相关性和循环性起源”海洋初步报告