Changes in the silt- and clay-size mineralogy of sediments at Ocean Drilling Program site 645B, Baffin Bay
Changes in the silt- and clay-size mineralogy of sediments at Ocean Drilling Program site 645B, Baffin Bay
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巴芬湾海洋钻探计划 645B 站点沉积物中淤泥和粘土尺寸矿物学的变化
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发表时间：
1993
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通讯作者：
J. Andrews
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作者：
J. Andrews
2010年，海洋钻探计划（ODP）第105个分支645B点在巴芬岛东部边缘水深m处进行了钻探。一个279米长的岩心可以追溯到约2 Ma。用x射线衍射技术分析了沉积物样品的粉土和粘土大小的矿物学。对这些数据的约束聚类分析定义了三个单元，表明矿物学的显著变化发生在海底以下约75 m (bsf)（约0.5 Ma）和155 m bsf（约1.15 Ma）。这些边界与ODP船上报告中指定的IA-IB和IB-II单元密切吻合，这些单元基于碎屑碳酸盐和砂的含量。单元II （1.2-2 Ma）的特征是零粘土级方解石和大量粘土级蒙脱石和粉粒级云母。Unit IB （0.5 - 1.15 Ma）值得注意的是，它首次出现粘土大小的方解石，大量的碎屑白云岩，以及粘土大小的高岭石的峰值。最高单位IA （0-0.5 Ma）的特点是始终保持高值…
Site 645B, Ocean Drilling Program (ODP) leg 105, was cored in 2010 m water depth off the eastern margin of Baffin Island. A 279 m core was dated as extending back to ca. 2 Ma. Samples of sediment were analyzed for their silt- and clay-size mineralogy using X-ray diffraction techniques. Constrained cluster analysis on these data defined three units, which indicated that significant changes in mineralogies occurred at approximately 75 m below sea floor (bsf) (ca. 0.5 Ma) and 155 m bsf (ca. 1.15 Ma). These boundaries coincide closely with units IA–IB and IB–II as designated in the ODP shipboard reports, and which were based on detrital carbonate and sand contents. Unit II (1.2–2 Ma) is characterized by zero clay-size calcite and high amounts of clay-size smectite and silt-size mica. Unit IB (0.5 – 1.15 Ma) is noteworthy for the first presence of clay-size calcite, high amounts of detrital dolomite, and a peak in clay-size kaolinite. The uppermost unit IA (0–0.5 Ma) is characterized by consistently high value...