Early Eocene to early Miocene radiolarian biostratigraphy for the low-latitude Pacific Ocean
Early Eocene to early Miocene radiolarian biostratigraphy for the low-latitude Pacific Ocean
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DOI：
10.29041/strat.09.1.03
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发表时间：
2012
期刊：
影响因子：
1.5
通讯作者：
S. Kamikuri;T. C. Moore;K. Ogane;N. Suzuki;H. Pälike;H. Nishi
中科院分区：
文献类型：
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作者：
S. Kamikuri;T. C. Moore;K. Ogane;N. Suzuki;H. Pälike;H. Nishi
在赤道太平洋U1331、U1332和U1333测点共鉴定了226个早始新世至早中新世放射虫基准事件，并与地质年代学尺度进行了对比。在低纬渐新世发现了7个新的放射虫亚带：透斑Eucyrtidium diaphanes区间亚带（RP22b）；Calocycletta (Calocycletta) robusta区间分区（RP22a）；apodora Lychnocanoma间隔亚区（RP21b）；红杉区间分区（RP21a）；蒲氏硅酸铕区间亚带（RP20c）；伪足棘间隙区（RP20b）；岩性旋回古斯塔段亚带（RP20a）。这些亚带显著提高了始渐新世的生物地层分辨率（平均每160万年一个亚带）。我们的研究证实了先前的研究，推断初级渐新世基准面在低纬太平洋是同步的。修正了4个始新世带，Cryptocarpium ornatum （RP19）、Calocyclas bandyca （RP18）、Phormocyrtis striata striata （RP9）和Buryella clinata （RP8）。本文报道了两个新种/亚种Lychnocanoma klausi和Theocorys anaclasta clasta。
A total of 226 early Eocene to early Miocene radiolarian datum events are identified and correlated with the geochronologic time scale at Sites U1331, U1332, and U1333 in the equatorial Pacific Ocean. Seven new radiolarian subzones are proposed for the low-latitude Oligocene: Eucyrtidium diaphanes Interval Subzone (RP22b); Calocycletta (Calocycletta) robusta Interval Subzone (RP22a); Lychnocanoma apodora Interval Subzone (RP21b); Theocyrtis annosa Interval Subzone (RP21a); Eucyrtidium plesiodiaphanes Interval Subzone (RP20c); Dorcadospyris pseudopapilio Interval Subzone (RP20b); Lithocyclia angusta Interval Subzone (RP20a). These subzones significantly improve the biostratigraphic resolution within th eOligocene (an average of one subzone per 1.6 million years [my]). Our study corroborates previous studies, which inferred that primary Oligocene datums were synchronous in the low-latitude Pacific. Four Eocene zones, Cryptocarpium ornatum (RP19), Calocyclas bandyca (RP18), Phormocyrtis striata striata (RP9), and Buryella clinata (RP8) are emended. Two new species/subspecies, Lychnocanoma klausi and Theocorys anaclasta clasta, are described.