CAJ | 학술논문

2008年在南日群岛东部海域用钻机采集长度为1004 cm的岩芯样品，测试沉积物中总有机碳（TOC）含量、稳定碳同位素比值（δ13CTOC）、碳氮比值（C/N）、碳酸盐含量以及14C数据，分析其垂直剖面上的变化特征，阐明其沉积环境和古气候的指示意义．沉积物TOC含量变化范围为0.44％～0.74％，垂直剖面上总体显示出末次冰期和全新世中期TOC含量较高，全新世早期相对稳定，而全新世中后期TOC波动范围明显增大．C/N值在5.3～14.9之间变化，平均值为8.1；δ13 CTOC值范围为-23.07‰～-21.04‰，表明沉积物中的有机质以海洋自生为主，同时混有部分陆源有机质．碳酸盐含量在3.3％～10.9％之间．TOC含量、C/N比值、δ13 CTOC值在岩芯垂直剖面上具有很好的相关性．14 C测年数据以及各要素测值在垂直剖面上的变化特征表明：自11250 aBP以来该海域附近古气候有可能经历了以下4个演化阶段：①11500～9000 aBP期间气候寒冷、海平面下降，采样点可能为浅水区或潮间带；②9000～8000 aBP期间为升温期，气候由寒冷转向温暖；③8000～4300 aBP期间，为相对稳定的暖湿期，在后期气候出现小幅的波动；④4300 aBP至今，气候进入明显的周期性波动期，暖湿和干冷气候多次交替变化；4300～3000 aBP期间为相对寒冷的时期；3000～1800 aBP期间为较稳定温暖期，1800～1000 aBP期间气温快速降低，标志着研究区进入一个新的寒冷阶段，但是自1000 aBP以来，气候又再次出现转暖的趋势．
2008년재남일군도동부해역용찬궤채집장도위1004 cm적암심양품，측시침적물중총유궤탄（TOC）함량、은정탄동위소비치（δ13CTOC）、탄담비치（C/N）、탄산염함량이급14C수거，분석기수직부면상적변화특정，천명기침적배경화고기후적지시의의．침적물TOC함량변화범위위0.44％～0.74％，수직부면상총체현시출말차빙기화전신세중기TOC함량교고，전신세조기상대은정，이전신세중후기TOC파동범위명현증대．C/N치재5.3～14.9지간변화，평균치위8.1；δ13 CTOC치범위위-23.07‰～-21.04‰，표명침적물중적유궤질이해양자생위주，동시혼유부분륙원유궤질．탄산염함량재3.3％～10.9％지간．TOC함량、C/N비치、δ13 CTOC치재암심수직부면상구유흔호적상관성．14 C측년수거이급각요소측치재수직부면상적변화특정표명：자11250 aBP이래해해역부근고기후유가능경력료이하4개연화계단：①11500～9000 aBP기간기후한랭、해평면하강，채양점가능위천수구혹조간대；②9000～8000 aBP기간위승온기，기후유한랭전향온난；③8000～4300 aBP기간，위상대은정적난습기，재후기기후출현소폭적파동；④4300 aBP지금，기후진입명현적주기성파동기，난습화간랭기후다차교체변화；4300～3000 aBP기간위상대한랭적시기；3000～1800 aBP기간위교은정온난기，1800～1000 aBP기간기온쾌속강저，표지착연구구진입일개신적한랭계단，단시자1000 aBP이래，기후우재차출현전난적추세．
The sediment cores were collected using drilling rig in 2008 at sites TS located in the eastern Nanri Islands.According to the characteristics of total organic carbon(TOC),organic carbon isotope values(δ13CTOC),in-organic carbon content,C/N and 14 C age in the sediment core,the depositional environment and paleoclimate changes of this area since the last glacial were analyzed.TOC in sediment varied from 0.44%to 0.74%.TOC con-tent was relatively high during the last glacial and interim Holocene,and varied little in Early Holocene and the range variation increased in late Holocene.The C/N values varied from 5.3 to 14.9,with average value 8.1,δ13CTOC values varied from -23.07‰to -21.04‰,suggesting that the contents of organic matter in the sediment are mainly controlled by marine origin.The inorganic carbon content varied from 3.3%to 10.9%.The results show that the δ13CTOC,TOC and C/N in core have a good relation with climate changes. <br> Based on14C age and above comprehensive analysis,it can be concluded that the paleoclimate of the study area has four stages as follows since 1 1 250 aBP. <br> (1 )1 1 500~9 000 aBP:during this stage the climate was cold and dry,the sea level descended,and the sampling site could be intertide;(2 )9 000 ~8 000 aBP:this stage the climate had been changing from cold to warm;(3)8 000~4 300 aBP:the climate was stable and warm and wet in this period,the climate appeared slight fluctuation in the late of period;(4)since 4 300 aBP:an instable stage since 4 300 aBP is suggested by the dramat-ic variation of all proxies;①a short cold stage occurred at 4 300~3 000 aBP;②the stage between 3 000~1 800 aBP,the climate is stable and warm;③the climate became cold the period of 1 800~1 000 aBP;④the tempera-ture have increased since the 1 000 aBP.