首页|期刊导航|中国海洋湖沼学报（英文版）|Trace element composition of peridotites from the southern Mariana forearc: Insights into the geochemical effects of serpentinization and/or seafloor weathering
Trace element composition of peridotites from the southern Mariana forearc: Insights into the geochemical effects of serpentinization and/or seafloor weathering
WANG Xiaomei ZENG Zhigang LIU Changhua CHEN Junbing YIN Xuebo WANG Xiaoyuan CHEN Daigeng ZHANG Guoliang LI Kang CHEN Shuai OUYANG Hegen
中国海洋湖沼学报（英文版）2009，Vol.27Issue(4)：985-992,8.
中国海洋湖沼学报（英文版）2009，Vol.27Issue(4)：985-992,8.DOI:10.1007/s00343-009-9252-6
Trace element composition of peridotites from the southern Mariana forearc: Insights into the geochemical effects of serpentinization and/or seafloor weathering
Trace element composition of peridotites from the southern Mariana forearc: Insights into the geochemical effects of serpentinization and/or seafloor weathering
摘要
Abstract
Peridotites from the southern Mariana forearc were sampled on the landward trench slope of the Izu-Bonin-Mariana (IBM) subduction zone by dredging. These mantle wedge peridotites underwent hydration by fluid derived from a dehydrated descending slab, and later interacted with seawater after emplacement at or near the seafloor. This study investigates how these two different rock-fluid interaction processes influenced trace element distribution in the southern Mariana forearc peridotites. We measured trace element concentrations of peridotites from the southern Mariana forearc. The southern Mariana forearc peridotites are characterized by a distinct seawater-like REE pattern with an obvious negative Ce anomaly, and La shows good correlation with other REEs (except Ce). In addition, there is a great enrichment of U, Pb, Sr and Li elements, which show a distinct positive anomaly relative to adjacent elements in the multi-element diagram. For the seawater-like REE pattern, we infer that REEs are mainly influenced by seawater during peridotite-seawater interactions after their emplacement at or near the seafloor, by serpentinization or by marine weathering. Furthermore, the anomalous behavior of Ce, compared with other rare earth elements in these samples, may indicate that they have undergone reactions involving Ce (IV) when the peridotites interacted with seawater. Positive U, Pb, Sr and Li anomalies are inferred to be related to seawater and/or fluids released during dehydration of the subducting slab.关键词
peridotites/ forearc/ Mariana/ element/ negative Ce anomalyKey words
peridotites/ forearc/ Mariana/ element/ negative Ce anomaly分类
海洋学引用本文复制引用
WANG Xiaomei,ZENG Zhigang,LIU Changhua,CHEN Junbing,YIN Xuebo,WANG Xiaoyuan,CHEN Daigeng,ZHANG Guoliang,LI Kang,CHEN Shuai,OUYANG Hegen..Trace element composition of peridotites from the southern Mariana forearc: Insights into the geochemical effects of serpentinization and/or seafloor weathering[J].中国海洋湖沼学报（英文版）,2009,27(4):985-992,8.基金项目
Supported by the Pilot Project of Knowledge Innovation Project, Chinese Academy of Sciences (Nos. KZCX2-YW-211, KZCX3-SW-223) （Nos. KZCX2-YW-211, KZCX3-SW-223）
the National Natural Science Foundation of China (No. 40830849), and the Special Foundation for the Eleventh Five-Year Plan of COMRA (No. DYXM-115-02-1-03). （No. 40830849）
