Age constraints on the origin and growth history of a deep-water coral mound in the northeast Atlantic drilled during Integrated Ocean Drilling Program Expedition 307
Age constraints on the origin and growth history of a deep-water coral mound in the northeast Atlantic drilled during Integrated Ocean Drilling Program Expedition 307
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DOI：
10.1130/g23917a.1
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发表时间：
2007-11-01
期刊：
影响因子：
5.8
通讯作者：
Li, Xianghui
中科院分区：
文献类型：
--
作者：
Kano, Akihiro;Ferdelman, Timothy G.;Li, Xianghui
锶同位素地层学提供了一个新的年龄模式，第一个完整的部分钻通过深水珊瑚丘。位于爱尔兰西南部豪猪湾的挑战者丘（Challenger Mound）的155米长的剖面位于中新世硅质碎屑岩上，完全由保存完好的冷水珊瑚Lophelia pertusa的沉积物组成。28个珊瑚样品的Sr-87/Sr-86值呈上升趋势，对应的年龄为2.6 ~ 0.5Ma。1.7至1.0 Ma，海底以下23.6 m。基丘沉积物的年龄与北方半球冰川的加剧相吻合，冰川形成了大西洋东北部的现代分层，使珊瑚得以生长。土丘生长持续整个冰川间冰期波动，达到最大速率（24厘米/千公里）。约2.0 Ma，并在1.7Ma停止。与豪猪湾的其他土丘不同，挑战者土墩在其生长中断期间仅被部分覆盖，约在1999年重新开始生长。1.0 MA.
Sr isotope stratigraphy provides a new age model for the first complete section drilled through a deep-water coral mound. The 155-m-long section from Challenger Mound in the Porcupine Seabight, southwest of Ireland, is on Miocene siliciclastics and consists entirely of sediments beating well-preserved cold-water coral Lophelia pertusa. The Sr-87/Sr-86 values of 28 coral specimens from the mound show an upward-increasing trend, correspond to ages from 2.6 to 0.5 Ma, and identify a significant hiatus from ca. 1.7 to 1.0 Ma at 23.6 m below seafloor. The age of the basal mound sediments coincides with the intensification of Northern Hemisphere glaciations that set up the modern stratification of the northeast Atlantic and enabled coral growth. Mound growth persisted throughout glacial-interglacial fluctuations, reached a maximum rate (24 cm/k.y.) ca. 2.0 Ma, and ceased at 1.7 Ma. Unlike other buried mounds in Porcupine Seabight, Challenger Mound was only partly covered during its growth interruption, and growth restarted ca. 1.0 Ma.