Geochemistry and age of seamounts in the West Pacific: mantle processes and petrogenetic implications

被引:11
作者
Tang, Limei [1 ,2 ]
Dong, Yanhui [1 ,2 ]
Chu, Fengyou [1 ,2 ]
Chen, Ling [1 ,2 ]
Ma, Weilin [1 ,2 ]
Liu, Yonggang [3 ]
机构
[1] Minist Nat Resources, Key Lab Submarine Geosci, Hangzhou 310012, Zhejiang, Peoples R China
[2] Minist Nat Resources, Inst Oceanog 2, Hangzhou 310012, Zhejiang, Peoples R China
[3] Minist Nat Resources, Guangzhou Marine Geol Survey, Guangzhou 510760, Guangdong, Peoples R China
基金
中国国家自然科学基金;
关键词
40Ar; 39Ar ages; geochemistry; magmatic evolution; basalts; West Pacific; FERROMANGANESE CRUST; CONVECTION PLUMES; SOUTH-PACIFIC; VOLCANISM; OLIVINE; PICRITES; MAGMAS; MELT;
D O I
10.1007/s13131-019-1371-0
中图分类号
P7 [海洋学];
学科分类号
0707 ;
摘要
Research on seamounts provides some of the best constraints for understanding intraplate volcanism, and samples from seamounts reveal crucial evidence about the geochemical makeup of the oceanic mantle. There are still many seamounts in the West Pacific Seamount Province (WPSP) that have not been studied, meaning their ages and geochemistry remain unknown. A better understanding of these seamount trails and their evolutionary history, investigated with age and geochemistry data, will enable better understanding of the geological processes operating underneath the Pacific Ocean Plate. Here, new 40Ar/39Ar ages and trace element and Sr-Nd-Pb isotopic data for seven basalt rocks from four seamounts in the WPSP are provided. Chemically, these rocks are all Oceanic Island Alkali basalt (OIA type); analysis of olivine phenocrysts shows that the magmas experienced strong olivine fractionation and changed from olivine + plagioclase to olivine + plagioclase + clinopyroxene cotectic during their evolution. Rare earth element (REE) patterns and a spider diagram of the samples in this study show OIB (Ocean Island Basalt) like behavior. The range of Sr-87/Sr-86 values is from 0.704 60 to 0.706 24, the range of Pb-206/Pb-204 values is from 18.241 to 18.599, and the range of Nd-143/Nd-144 values is from 0.512 646 to 0.512 826; together, these values indicate magma sources ranging from EMI to EMII. Finally, new 40Ar/39Ar age data show that these seamounts formed at 97 and 106 Ma, indicating that some may have undergone the same formation processes as seamounts in the eastern part of the Magellan Seamount Trail, but other seamounts likely have different origins.
引用
收藏
页码:71 / 77
页数:7
相关论文
共 47 条
  • [1] Anderson D L, 2005, PLUME ASSUMPTION FRE
  • [2] Anderson DL, 2007, NEW THEORY OF THE EARTH, P1, DOI 10.1017/CBO9781139167291
  • [3] Anderson DL, 2002, GEOLOGY, V30, P411, DOI 10.1130/0091-7613(2002)030<0411:HMP>2.0.CO
  • [4] 2
  • [5] [初凤友 Chu Fengyou], 2005, [海洋地质与第四纪地质, Marine Geology & Quaternary Geology], V25, P55
  • [6] Chu FY, 2006, ACTA OCEANOL SIN, V25, P63
  • [7] Clague DA., 1989, GEOLOGY N AM, P188
  • [8] PYROCLASTIC ROCKS - ANOTHER MANIFESTATION OF ULTRAMAFIC VOLCANISM ON GORGONA ISLAND, COLOMBIA
    ECHEVERRIA, LM
    AITKEN, BG
    [J]. CONTRIBUTIONS TO MINERALOGY AND PETROLOGY, 1986, 92 (04) : 428 - 436
  • [9] Plumes, or plate tectonic processes?
    Foulger, G
    [J]. ASTRONOMY & GEOPHYSICS, 2002, 43 (06) : 19 - 23
  • [10] Foulger G R, 2010, PLATE TECTONICS PLUM