南黄海中部泥质区YE-2孔8.4kaBP来的沉积特征  

SEDIMENTARY CHARACTERISTICS OF CORE YE-2 FROM THE CENTRAL MUD AREA IN THE SOUTH YELLOW SEA DURING LAST 8400 YEARS AND ITS INTERSPACE COARSE LAYERS

作　　者：王利波[1,2] 杨作升[1,2] 赵晓辉[1,2] 邢磊[3] 赵美训[3] Yoshiki Saito 范德江[1,2] 

机构地区：[1]中国海洋大学海洋地球科学学院,青岛266100 [2]中国海洋大学海底科学与探测技术教育部重点实验室,青岛266100 [3]中国海洋大学海洋化学理论与工程技术教育部重点实验室及海洋有机地球化学研究所,青岛266100 [4]Geological Survey of Japan,AIST

出　　处：《海洋地质与第四纪地质》2009年第5期1-11,共11页Marine Geology & Quaternary Geology

基　　金：国家自然科学基金项目(90211022;40676032);国家重点基础研究发展规划项目(2005CB422304)

摘　　要：对取自南黄海中部泥质区YE-2钻孔的6.1m岩心进行了年代学、沉积学、微体古生物学和U3K7′海表温度分析,结果显示,该孔沉积物基本类型为黏土质粉砂,8400aBP来的沉积环境可分为3段:8.4～6.9kaBP为砂含量达13%的滨岸浅水环境;6.9～6.1kaBP为砂含量8%的滨岸浅水向稳定浅海过渡的环境;6.1～0kaBP为基本不含砂的黏土质粉砂稳定浅海环境。表层海水温度(SST)在滨岸浅水阶段较低,平均约14.2℃;在第2阶段从6.9kaBP开始增加,最高达18.1℃,指示了黄海暖流的入侵;6.4kaBP增温结束后,浅海阶段SST稳定在15～16℃之间,同时有3个SST平均为13.9℃的短暂低温期,大致为5.7～5.2、3.7～3.2和2.3～1.8kaBP。在稳定浅海环境的黏土质粉砂地层中发现了罕见的3个砂质粉砂质粗粒级夹层,大致形成于6.0、3.9和2.5kaBP,其粒度具有风暴沉积特征,重矿物表现出变质岩特点,U3K7′-SST和黏土矿物指示其沉积环境的温度偏高。上述特征与岩心其他所有层位差异较大,显示了异地搬运的特征,可能为风暴沉积。根据AMS14C测年,不考虑风暴沉积,YE-2岩心的沉积速率在50.7～75.6cm/ka之间。Based on chronological, sedimentological, micropaleontological and U37^R-sea surface temperature data of core YE-2 from the central mud area of the South Yellow Sea, evolution of the marine environment in the past 8 400 years and three interspace sandy layers in the core were studied. The core is mainly composed of clayey silt, and evolution of marine environment during the last 8 400 years experienced three phases： （1） Near-shore shallow water environment with sand content of 13% at about 8.4-6.9 kaBP; （2） Transitional marine environment from near-shore shallow water to stable shallow sea with sand content of 8% at about 6. 9-6. 1 kaBP; （3） Stable shallow sea environment with sediment without sand at about 6.1 -0 kaBP. Sea surface temperature （SST） was low in the near shore shallow water phase, about 14. 2℃ on average. And the SST began to increase at the beginning of the second phase, about 6.9 kaBP, indicating intrusion of the Yellow Sea Warm Current with the highest SST up to 18.1℃. The SST stopped increasing at 6.4 kaBP. After that the SST was stable from 15℃ to 16℃ with some fluctuations in the shallow sea phase, excluding three low temperature periods at about 5.7-5.2, 3. 7-3.2 and 2. 3-1.8 kaBP respee tively, whose temperature was about 13.9℃ on average. Three abnormal sandy silt coarse interlayers deposited in stable shallow sea environment,were speculated to have formed in 6.0, 3.9 and 2.5 kaBP respectively. Grain-sizes of the sandy layers show characteristics of storm deposition. Heavy mineral compo- sitions of the sandy layers show characteristics of the origin of metamorphic rocks. U37^K-SST and clay mineral compositions of the sandy layers indicate a sedimentary environment with higher temperature than that in shallow sea. These characteristics of sandy layers are different from other sediment in the core, indicating great differentce between the sandy layer and other strata in provenance. Therefore, the three coarse layers are speculated to he the storm deposition. Witho

关 键 词：泥质沉积 古环境 U37K′-SST 粗粒级夹层 南黄海 

分 类 号：P736.21[天文地球—海洋地质]