Climatically sensitive eolian and hemipelagic deposition in the Cariaco Basin, Venezuela, over the past 578,000 years: Results from Al/Ti and K/Al
Climatically sensitive eolian and hemipelagic deposition in the Cariaco Basin, Venezuela, over the past 578,000 years: Results from Al/Ti and K/Al
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DOI：
10.1029/1999pa900048
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发表时间：
2000-04
期刊：
影响因子：
--
通讯作者：
K. Yarincik;R. Murray;L. Peterson
中科院分区：
文献类型：
--
作者：
K. Yarincik;R. Murray;L. Peterson
Al/Ti和K/Al在散装沉积物的比例被用来解释风吹和半远洋沉积源的578 kyr记录在Cariaco盆地，委内瑞拉（大洋钻探计划网站1002）。图形和交叉光谱分析表明，这些比值与南极有孔虫δ 18 O的变化非常接近，两个比值在间冰期期间明显较高，在冰期期间较低。K/Al表明，在冰川期间，海平面较低，导致相对盆地隔离增加了来自当地河流排水相对潮湿的委内瑞拉边缘的高岭石的相对比例。Al/Ti在冰川期降低，表明风成金红石的比例更大，来源于北方撒哈拉沙漠（由于风力和/或干旱增加）。这种解释是一致的化学和矿物学的撒哈拉衍生风成物质在加勒比地区的研究，并与质量平衡确定的影响，风成金红石堆积的散装沉积Al/Ti比的变化。
Al/Ti and K/Al ratios in bulk sediment are used to interpret wind-blown and hemipelagic sources of deposition to a 578 kyr record in the Cariaco Basin, Venezuela (Ocean Drilling Program site 1002). Graphical and cross-spectral analyses indicate that these ratios vary extremely closely with planktonic foraminiferal δ18O, with both ratios being significantly higher during interglacials and lower during glacials. K/Al indicates that during glacials the lower sea level that results in relative basin isolation increases the relative proportion of kaolinite derived from local rivers draining the relatively humid Venezuelan margin. Al/Ti decreases during glacials, suggesting greater proportions of eolian rutile sourced from the northern Sahara (due to increased wind strength and/or aridity). This interpretation is consistent with previous studies of the chemistry and mineralogy of Saharan-derived eolian matter in the Caribbean and with a mass balance determining the effect of changes in eolian rutile accumulation on the bulk sedimentary Al/Ti ratio.