Distribution and provenance of wind-blown SE Pacific surface sediments
Distribution and provenance of wind-blown SE Pacific surface sediments
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东南太平洋表层风沉积物的分布和来源
DOI：
10.1016/j.margeo.2010.12.006
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发表时间：
2011
期刊：
影响因子：
2.9
通讯作者：
C. Vogt
中科院分区：
文献类型：
--
作者：
Saukel;J. B. W;Tiedemann;C. Vogt
低纬度海洋-大气相互作用的重建是（古）环境研究的主要问题之一。信风在两个半球纬度 20° 至 30° 范围内延伸，位于副热带高压和热带辐合带之间，是大气环流的主要组成部分，但人们对它们在地质时间尺度上的长期变化知之甚少，特别是在太平洋区域。我们提出了东赤道和副热带太平洋（10°N 至 25°S）风成海洋沉积物的现代空间格局，作为解释东南太平洋古尘埃记录的参考数据集。已分别研究了 75 个表面沉积物样品的陆源粉砂和粘土部分的粒度分布和粘土矿物组成，以确定其来源和运输媒介。由于东南信风的低层输送，从秘鲁和智利的半干旱至超干旱地区输送到东南太平洋的沙尘颗粒相当细（4-8μm）。然而，风是主要的输送媒介，风成物质是秘鲁-智利海沟以南约 5°S 以西的主要陆源成分。由于海底山脊上自生颗粒的形成以及加拉帕戈斯群岛周围丰富的火山玻璃，仅粒度分布不足以识别海洋沉积物中的风成信号。结合粘土部分的粘土矿物成分，我们确定了从秘鲁和智利海岸延伸到加拉帕戈斯海隆以及穿过赤道进入低迷区的尘埃瓣。伊利石是一个非常有用的参数，可用于识别这个以蒙皂石为主的研究区域的灰尘源区域。
The reconstruction of low-latitude ocean–atmosphere interactions is one of the major issues of (paleo-)environmental studies. The trade winds, extending over 20° to 30° of latitude in both hemispheres, between the subtropical highs and the intertropical convergence zone, are major components of the atmospheric circulation and little is known about their long-term variability on geological time-scales, in particular in the Pacific sector. We present the modern spatial pattern of eolian-derived marine sediments in the eastern equatorial and subtropical Pacific (10°N to 25°S) as a reference data set for the interpretation of SE Pacific paleo-dust records. The terrigenous silt and clay fractions of 75 surface sediment samples have been investigated for their grain-size distribution and clay-mineral compositions, respectively, to identify their provenances and transport agents. Dust delivered to the southeast Pacific from the semi- to hyper-arid areas of Peru and Chile is rather fine-grained (4–8μm) due to low-level transport within the southeast trade winds. Nevertheless, wind is the dominant transport agent and eolian material is the dominant terrigenous component west of the Peru–Chile Trench south of ~5°S. Grain-size distributions alone are insufficient to identify the eolian signal in marine sediments due to authigenic particle formation on the sub-oceanic ridges and abundant volcanic glass around the Galapagos Islands. Together with the clay-mineral compositions of the clay fraction, we have identified the dust lobe extending from the coasts of Peru and Chile onto Galapagos Rise as well as across the equator into the doldrums. Illite is a very useful parameter to identify source areas of dust in this smectite-dominated study area.
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影响因子：
--
作者：
J. Prospero;E. Bonatti
通讯作者：
E. Bonatti
影响因子：
2.2
作者：
R. Rex;B. Martin
通讯作者：
B. Martin
影响因子：
3.9
作者：
V. Flores‐Aqueveque;S. Alfaro;R. Muñoz;J. Rutllant;S. Caquineau;J. P. Roux;G. Vargas
通讯作者：
V. Flores‐Aqueveque;S. Alfaro;R. Muñoz;J. Rutllant;S. Caquineau;J. P. Roux;G. Vargas
南太平洋远洋沉积物中的长石分布
影响因子：
--
作者：
M. Peterson;E. Goldberg
通讯作者：
E. Goldberg
影响因子：
5.2
作者：
Department oJ Geology Prnnnn E. Brsceve;Yale Jniversily;Connecticut.l H aven;Ansrnacr
通讯作者：
Department oJ Geology Prnnnn E. Brsceve;Yale Jniversily;Connecticut.l H aven;Ansrnacr