Late Quaternary climate change record from two long sediment cores from Guaymas Basin, Gulf of California
Late Quaternary climate change record from two long sediment cores from Guaymas Basin, Gulf of California
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DOI：
10.1002/jqs.944
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发表时间：
2005-07-01
影响因子：
2.3
通讯作者：
Nederbragt, AJ
中科院分区：
文献类型：
--
作者：
Cheshire, H;Thurow, J;Nederbragt, AJ
现代瓜伊马斯盆地（墨西哥加州湾）是一个硅藻高产地区，特殊的保存因素保持每年两次交替沉积物沉积作为年度纹藻。来自瓜伊马斯盆地的新沉积物芯（MD 02 -2512和MD 02 -2515）提供了构建末次冰期以下气候记录的机会。通过氧同位素分析、与瓜伊马斯盆地其他定年短活塞岩心的对比以及沉积速率的估算，建立了低分辨率的年龄模型。瓜伊马斯盆地东部的MD 02 -2512的年龄范围为全新世至晚海相同位素第6阶段（MIS 6）;瓜伊马斯盆地西部的MD 02 -2515的年龄范围为8000 ~ 40000年。船上的颜色反射率，磁化率和沉积物密度的分析与连续X射线荧光扫描相结合，以重建在加州湾的冰川气候的图片。东瓜伊马斯盆地受冰川期海平面下降的影响，导致生产率和沉积物类型的急剧变化。MIS 5的层压记录可以与全新世进行比较，显示出冰消期沉积模式的相似性，以及末次冰期之前的一系列非常快速的变化。瓜伊马斯盆地西部在冰期发生了一系列类似新仙女木事件，表现为低生产力和高陆源输入。气候和生产力的长期变化似乎是由副热带高压带的南移引起的。版权所有（C）2005约翰威利父子有限公司
Modern Guaymas Basin (Gulf of California, Mexico) is a region of high diatom productivity where exceptional preservation factors maintain biannually alternating sediment deposition as annual varves. New sediment cores from Guaymas Basin (MD02-2512 and MD02-2515) present the opportunity to construct climate records from below the last glacial period. A low-resolution age model has been constructed from oxygen isotope analysis, correlation with other dated short piston cores from Guaymas Basin and an estimate of sedimentation rate. MD02-2512 from eastern Guaymas Basin has an age range from the Holocene to late marine isotope stage 6 (MIS 6); MD02-2515 from western Guaymas Basin has an age range from similar to 8000 to 40000 yr. Shipboard analyses of colour reflectance, magnetic susceptibility and sediment density are combined with continuous X-ray fluorescence scans to reconstruct a picture of glacial climate in the Gulf of California. Eastern Guaymas Basin is affected by glacial sea level fall, which results in a drastic change in productivity rates and sediment type. The laminated record of MIS 5 allows comparison with the Holocene, showing a similarity of sedimentation patterns during deglaciation and a series of very rapid variations just prior to the last glaciation. In western Guaymas Basin there are a series of Younger Dryas-like events during the glacial, typified by low productivity and high terrigenous input. Long-term climate and productivity changes appear to be caused by the southward displacernent of the Subtropical High pressure zone. Copyright (C) 2005 John Wiley & Sons, Ltd.