Tectonic and oceanographic control of sedimentary patterns in a small oceanic basin: Dove Basin (Scotia Sea, Antarctica)
Tectonic and oceanographic control of sedimentary patterns in a small oceanic basin: Dove Basin (Scotia Sea, Antarctica)
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小型海洋盆地沉积模式的构造和海洋学控制：多夫盆地（南极洲斯科舍海）
DOI：
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
J. Galindo‐Zaldívar
中科院分区：
文献类型：
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作者：
L. Pérez;A. Maldonado;F. Hernández‐Molina;E. Lodolo;F. Bohoyo;J. Galindo‐Zaldívar
达夫盆地是位于斯科舍海南部的一个小洋域，其构造演化与斯科舍弧的形成密切相关。该盆地还横跨南大洋主要水团之间的交汇处：南极绕极流（ACC）、东南太平洋深水（SPDW）和威德尔海深水（WSDW）。对多道地震反射剖面的分析，加上条带测深数据，揭示了盆地的主要结构和沉积物分布，从而可以重建盆地的构造地层演变，并评估影响其沉积发展的主要底层水流。分散在盆地中的沉积物在很大程度上受到来自邻近大陆边缘的重力驱动的运输的影响，后来又受到深海底流的影响。来自融化的冰山和广阔的冰盖的沉积物也有助于盆地沉积的一小部分。我们确定了四个阶段的盆地演化-根据区域年龄假设-发生在早中新世，中中新世，晚中新世-早上新世和晚上新世-第四纪。在鸽子盆地的ACC流在中新世早期，WSDW流在中新世中期，和SPDW在中新世晚期的发病受到构造事件的影响，促进了该地区新的海洋门户的开放。Dove盆地的分析表明，构造是影响其沉积堆积模式的主要因素，新海洋门户的结构发展允许深水流动的开始，自那时起控制了沉积过程。
Dove Basin, a small oceanic domain located within the southern Scotia Sea, evidences a complex tectonic evolution linked to the development of the Scotia Arc. The basin also straddles the junction between the main Southern Ocean water masses: the Antarctic Circumpolar Current (ACC), the Southeast Pacific Deep Water (SPDW) and the Weddell Sea Deep Water (WSDW). Analysis of multichannel seismic reflection profiles, together with swath bathymetry data, reveals the main structure and sediment distribution of the basin, allowing a reconstruction of the tectonostratigraphic evolution of the basin and assessment of the main bottom water flows that influenced its depositional development. Sediment dispersed in the basin was largely influenced by gravity‐driven transport from adjacent continental margins, later modified by deep bottom currents. Sediments derived from melting icebergs and extensive ice sheets also contributed to a fraction of the basin deposits. We identify four stages in the basin evolution which – based on regional age assumptions – took place during the early Miocene, middle Miocene, late Miocene–early Pliocene and late Pliocene–Quaternary. The onsets of the ACC flow in Dove Basin during the early Miocene, the WSDW flow during the middle Miocene, and the SPDW during the late Miocene were influenced by tectonic events that facilitated the opening of new oceanic gateways in the region. The analysis of Dove Basin reveals that tectonics is a primary factor influencing its sedimentary stacking patterns, the structural development of new oceanic gateways permitting the inception of deep‐water flows that have since controlled the sedimentary processes.