The silicon isotope composition of Ethmodiscus rex laminated diatom mats from the tropical West Pacific: Implications for silicate cycling during the Last Glacial Maximum
The silicon isotope composition of Ethmodiscus rex laminated diatom mats from the tropical West Pacific: Implications for silicate cycling during the Last Glacial Maximum
复制标题
来自热带西太平洋的霸王龙叠层硅藻垫的硅同位素组成：对末次盛冰期期间硅酸盐循环的影响
DOI：
10.1002/2015pa002793
复制
发表时间：
2015-07
期刊：
影响因子：
--
通讯作者：
Zhai Bin
中科院分区：
文献类型：
--
作者：
Xiong Zhifang;Li Tiegang;Algeo Thomas;Doering Kristin;Frank Martin;Brzezinski Mark A.;Chang Fengming;Opfergelt Sophie;Crosta Xavier;Jiang Fuqing;Wan Shiming;Zhai Bin
The cause of massive blooms of Ethmodiscus rex laminated diatom mats (LDMs) in the eastern Philippine Sea (EPS) during the Last Glacial Maximum (LGM) remains uncertain. In order to better understand the mechanism of formation of E. rex LDMs from the perspective of dissolved silicon (DSi) utilization, we determined the silicon isotopic composition of single E. rex diatom frustules (δ30SiE. rex) from two sediment cores in the Parece Vela Basin of the EPS. In the study cores, δ30SiE. rex varies from −1.23‰ to −0.83‰ (average −1.04‰), a range that is atypical of marine diatom δ30Si and that corresponds to the lower limit of reported diatom δ30Si values of any age. A binary mixing model (upwelled silicon versus eolian silicon) accounting for silicon isotopic fractionation during DSi uptake by diatoms was constructed. The binary mixing model demonstrates that E. rex dominantly utilized DSi from eolian sources (i.e., Asian dust) with only minor contributions from upwelled seawater sources (i.e., advected from Subantarctic Mode Water, Antarctic Intermediate Water, or North Pacific Intermediate Water). E. rex utilized only ~24% of available DSi, indicating that surface waters of the EPS were eutrophic with respect to silicon during the LGM. Our results suggest that giant diatoms did not always use a buoyancy strategy to obtain nutrients from the deep nutrient pool, thus revising previously proposed models for the formation of E. rex LDMs.
登录
查看更多内容
影响因子：
64.8
作者：
K. A. Rose;E. Sikes;T. Guilderson;P. Shane;T. Hill;R. Zahn;H. Spero
通讯作者：
K. A. Rose;E. Sikes;T. Guilderson;P. Shane;T. Hill;R. Zahn;H. Spero
影响因子：
5.2
作者：
S. Kienast;M. Kienast;S. Jaccard;S. Calvert;R. Francois
通讯作者：
S. Kienast;M. Kienast;S. Jaccard;S. Calvert;R. Francois
影响因子：
3
作者：
Tie Li;T. Masuzawa;H. Kitagawa
通讯作者：
Tie Li;T. Masuzawa;H. Kitagawa
影响因子：
64.8
作者：
L. Pichevin;B. Reynolds;R. Ganeshram;I. Cacho;L. Pena;K. Keefe;R. Ellam
通讯作者：
L. Pichevin;B. Reynolds;R. Ganeshram;I. Cacho;L. Pena;K. Keefe;R. Ellam
影响因子：
5
作者：
C. Rocha;Pierre Bescont;Alice Croguennoc;E. Ponzevera
通讯作者：
C. Rocha;Pierre Bescont;Alice Croguennoc;E. Ponzevera