ODP Site 1092: revised composite depth section has implications for Upper Miocene ‘cryptochrons’
ODP Site 1092: revised composite depth section has implications for Upper Miocene ‘cryptochrons’
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DOI：
10.1111/j.1365-246x.2003.02189.x
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发表时间：
2003-12
影响因子：
2.8
通讯作者：
H. Evans;T. Westerhold;J. Channell
中科院分区：
文献类型：
--
作者：
H. Evans;T. Westerhold;J. Channell
南极南部大西洋以下的ODP1092站的C3r至C5ABn段的上中新世磁极地层学已经被开发出来(Evans&Channell 2003)。对半个岩心的X射线荧光(XRF)扫描的新数据导致编制了该地点的修订复合深度剖面。这对磁性地层学的解释具有重要意义。利用舰载合成切片，在与C5n.2n相关的正常极化区内识别出四个亚时区。修正的复合剖面使Evans&Channell(2003)的C5n.2n-2和C5n.2n-3亚时线成为两个重叠岩芯中记录的单个亚时线。修正后的C5n.2n中的极性亚微管数量现在是三个，而不是四个，这与海洋异常数据中识别的“隐形微管”的数量一致。
SUMMARY An Upper Miocene magnetic polarity stratigraphy has been developed for the C3r to C5ABn interval of ODP site 1092 from the sub-Antarctic South Atlantic (Evans & Channell 2003). New data from X-ray fluorescence (XRF) scanning of half cores has led to development of a revised composite depth section for the site. This has implications for the magnetostratigraphic interpretation. Using the shipboard-derived composite section, four subchrons were identified within the normal polarity zone correlative to C5n.2n. The revised composite section results in subchrons C5n.2n-2 and C5n.2n-3 of Evans & Channell (2003) becoming a single subchron recorded in two overlapping cores. The revised number of polarity subchrons within C5n.2n is now three, rather than four, which is consistent with the number of ‘cryptochrons’ recognized in marine oceanic anomaly data.