现代地质
現代地質
현대지질
Geoscience
2015年
4期
777-788
,共12页
蓝先洪%梅西%李日辉%张志繤%李杰%顾兆峰
藍先洪%梅西%李日輝%張誌繤%李傑%顧兆峰
람선홍%매서%리일휘%장지찬%리걸%고조봉
沉积物%晚更新世%物源分析%南黄海北部
沉積物%晚更新世%物源分析%南黃海北部
침적물%만경신세%물원분석%남황해북부
sediment%Late Pleistocene%source analysis%northern South Yellow Sea
为研究南黄海北部泥质区元素地球化学特征对于地层划分与物质来源的指示意义,对南黄海北部DLC70-3孔(孔深71.20 m)沉积物作了元素地球化学分析和物源判别。根据元素含量及比值的变化,可将DLC70-3孔岩心划分为5层,它们分别反映了末次间冰期(暖期)晚期以来黄海海面波动以及沉积物物源的变化。运用判别函数、MgO/Na2 O与CIA的散点图等方法分析了DLC70-3孔沉积物的物质来源,结果显示该孔沉积物主要来源于黄河,长江物质对该孔中上部及下部沉积物有较明显影响。DLC70-3孔物源指数反映0~4.50 m和27.80~38.80 m沉积物以黄河源为主,4.50~27.80 m、38.80~55.00 m和55.00~71.20 m沉积物以长江源为主;可见黄河从晚更新世中期到现代对南黄海北部沉积起着重要作用,而长江物质在晚更新世早期开始对南黄海北部沉积就有明显影响。
為研究南黃海北部泥質區元素地毬化學特徵對于地層劃分與物質來源的指示意義,對南黃海北部DLC70-3孔(孔深71.20 m)沉積物作瞭元素地毬化學分析和物源判彆。根據元素含量及比值的變化,可將DLC70-3孔巖心劃分為5層,它們分彆反映瞭末次間冰期(暖期)晚期以來黃海海麵波動以及沉積物物源的變化。運用判彆函數、MgO/Na2 O與CIA的散點圖等方法分析瞭DLC70-3孔沉積物的物質來源,結果顯示該孔沉積物主要來源于黃河,長江物質對該孔中上部及下部沉積物有較明顯影響。DLC70-3孔物源指數反映0~4.50 m和27.80~38.80 m沉積物以黃河源為主,4.50~27.80 m、38.80~55.00 m和55.00~71.20 m沉積物以長江源為主;可見黃河從晚更新世中期到現代對南黃海北部沉積起著重要作用,而長江物質在晚更新世早期開始對南黃海北部沉積就有明顯影響。
위연구남황해북부니질구원소지구화학특정대우지층화분여물질래원적지시의의,대남황해북부DLC70-3공(공심71.20 m)침적물작료원소지구화학분석화물원판별。근거원소함량급비치적변화,가장DLC70-3공암심화분위5층,타문분별반영료말차간빙기(난기)만기이래황해해면파동이급침적물물원적변화。운용판별함수、MgO/Na2 O여CIA적산점도등방법분석료DLC70-3공침적물적물질래원,결과현시해공침적물주요래원우황하,장강물질대해공중상부급하부침적물유교명현영향。DLC70-3공물원지수반영0~4.50 m화27.80~38.80 m침적물이황하원위주,4.50~27.80 m、38.80~55.00 m화55.00~71.20 m침적물이장강원위주;가견황하종만경신세중기도현대대남황해북부침적기착중요작용,이장강물질재만경신세조기개시대남황해북부침적취유명현영향。
The sediment samples derived from drillhole DLC70 -3 (71.20 meters in depth)in the northern South Yellow Sea were measured for analysis of element geochemistry and their provenances were discriminated with the purpose of studying the indicator significance of element geochemistry information for the stratigraphic division and provenance analysis of mud area in northern South Yellow Sea.According to the changing law of el-ement contents and their ratios,the sediments from drillhole DLC70-3 can be divided into five layers,reflec-ting the fluctuation of sea level and the change of sediment sources in northern South Yellow Sea since the late of the last interglacial cycle (warm period).Combined with discriminate function,the scatter diagrams of MgO/Na2 O vs.CIA were drawn to determine the material source of sediments from drillhole DLC70-3 .The results revealed that the material sources of sediments mainly came from the Yellow River,and sediments in the upper-middle and in the lower of the drillhole were apparently influenced by materials from the Changjiang River.The sediments above the depth of 4.50 m in the upper and between 27.80 m and 38.80 m in the middle of drillhole DLC70-3 mainly belong to the Yellow River source;the sediments from 4.50 m to 27.80 m in the upper-mid-dle,from 38.80 m to 55.00 m in the lower and from 55.00 m to 71.20 m at the bottom were mainly derived from the Changjiang River.It is concluded that the Yellow River is playing an important role in northern South Yellow Sea at the middle stage of Late Pleistocene and the Changjiang River has started to obviously influence northern South Yellow Sea since early Late Pleistocene.