陈志华, 黄元辉, 唐正, 王豪壮, 葛淑兰, 方习生, 韩喜彬, 王爱军, 武力, 朱志敏. 南极半岛东北部海域表层沉积物稀土元素特征及物源指示意义[J]. 海洋地质与第四纪地质, 2015, 35(3): 145-155. DOI: 10.3724/SP.J.1140.2015.03145
引用本文: 陈志华, 黄元辉, 唐正, 王豪壮, 葛淑兰, 方习生, 韩喜彬, 王爱军, 武力, 朱志敏. 南极半岛东北部海域表层沉积物稀土元素特征及物源指示意义[J]. 海洋地质与第四纪地质, 2015, 35(3): 145-155. DOI: 10.3724/SP.J.1140.2015.03145
CHEN Zhihua, HUANG Yuanhui, TANG Zheng, WANG Haozhuang, GE Shulan, FANG Xisheng, HAN Xibin, WANG Aijun, WU Li, ZHU Zhimin. RARE EARTH ELEMENTS IN THE OFFSHORE SURFACE SEDIMENTS OF THE NORTHEASTERN ANTARCTIC PENINSULA AND THEIR IMPLICATIONS FOR PROVENANCE[J]. Marine Geology & Quaternary Geology, 2015, 35(3): 145-155. DOI: 10.3724/SP.J.1140.2015.03145
Citation: CHEN Zhihua, HUANG Yuanhui, TANG Zheng, WANG Haozhuang, GE Shulan, FANG Xisheng, HAN Xibin, WANG Aijun, WU Li, ZHU Zhimin. RARE EARTH ELEMENTS IN THE OFFSHORE SURFACE SEDIMENTS OF THE NORTHEASTERN ANTARCTIC PENINSULA AND THEIR IMPLICATIONS FOR PROVENANCE[J]. Marine Geology & Quaternary Geology, 2015, 35(3): 145-155. DOI: 10.3724/SP.J.1140.2015.03145

南极半岛东北部海域表层沉积物稀土元素特征及物源指示意义

RARE EARTH ELEMENTS IN THE OFFSHORE SURFACE SEDIMENTS OF THE NORTHEASTERN ANTARCTIC PENINSULA AND THEIR IMPLICATIONS FOR PROVENANCE

  • 摘要: 通过对南极半岛东北部海域36个表层沉积物样品的稀土元素分析发现:(1)研究区表层沉积物中稀土元素总量(REE)的分布范围为(45.47~183.60)×10-6,平均值为91.36×10-6;稀土元素含量的高低与铝硅酸盐黏土成正比,与生物硅含量成反比;(2)大致以象岛至南极半岛北部的茹安维尔岛为界,研究区西部的布兰斯菲尔德海峡及南设得兰群岛北部岛架-岛坡沉积物稀土含量较低,稀土元素页岩标准化模式与长城站周边土壤/湖泊沉积物、火山岩相一致,表现为重稀土相对富集,铕正异常明显,Sm/Nd分子比值大,推断该区沉积物主要来源于南设德兰群岛中-新生代火山岩分布区与现代火山活动区;(3)研究区东部鲍威尔海盆、南奥克尼群岛岛架和南斯科舍海脊区沉积物稀土元素的页岩标准化配分模式表现为平坦型,轻稀土明显抬升,铕正异常不显著,Sm/Nd分子比值小,稀土元素含量受沉积物中黏土组分含量、硅质生物组分等制约,推断沉积物陆源碎屑主要来源于威德尔海西部和南部,局部受南奥尼克群岛、南斯科舍海脊和南设德兰群岛物质的影响,沉积物的搬运主要受冰筏和海流制约。

     

    Abstract: Chemical analyses for rare earth elements have been carried out for a total of 36 samples taken from the surface sediments off the northeastern Antarctic Peninsula in order to study the the sources of sedimens. Data show that the REE concentrations of surface sediments, which ranges within 45.47~183.60×10-6 and is 91.36×10-6 on average, increase with fine-grained materials dominated by clay and decrease with biogenic silica. In the areas to the west of the line from the Joinville Island to the Elephant Island, including the Bransfield Strait and the shelf/slope of the South Shetland Islands, surface sediments are characterized by low REE concentrations, HREE enrichments, positive europium anomalies (δEu) relative to global shale average, and larger Sm/Nd molecular ratios, indicating that they were mainly derived from the South Shetland Islands where the Mesozoic/Cenozoic, in particular the Holocene volcanisms were active. In the eastern area, including the Powell Basin, the South Orkney Islands shelf and the South Scotia Ridge, the sediments have similar flat shale-normalized REE patterns, elevated LREE, weak positive europium anomalies (δEu) and smaller Sm/Nd molecular ratios while REE concentrations are controlled by clay and biogenic silica as well. It is inferred that the terrigenous components are derived mainly from the western and southern Weddell Sea, and secondarily from the South Orkney Islands, the South Scotia Ridge and the South Shetland Islands by ice-rafting and current transport.

     

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