Chalcophile elements are enriched in the Cretaceous–Paleogene (KPg) boundary clays from Stevns Klint, Denmark. As the concentrations of Cu, Ag, and Pb among several chalcophile elements such as Cu, Zn, Ga, As, Ag, and Pb are correlated with those of Ir, we suggest that these elements were supplied to the oceans by processes related to the end-Cretaceous asteroid impact. Synchrotron X-ray fluorescence images revealed that Cu and Ag exist as trace elements in pyrite grains or as 1–10-µm-sized discrete phases specifically enriched in Cu or Ag. The difference in carrier phases might depend on the materials that transported these elements to the seafloor. Based on their affinities with Cu, Ag, and Ir, iron oxides/hydroxides and organic matter were identified as the potential carrier phases that supplied these elements to the seafloor. Chalcophile elements adsorbed on iron oxides/hydroxides might have been released during reductive dissolution of iron oxides/hydroxides and incorporated into the pyrite produced simultaneously with the reductive dissolution of iron oxides/hydroxides. Both iron oxides/hydroxides and chalcophile elements were possibly released from the KPg target rocks (i.e., sedimentary rocks and/or basement crystalline rocks) by impact heating.Elements with a high affinity to organic matter would have been released upon its degradation and then converted into discrete minerals because of the deficiency in Fe ions. As such discrete minerals include the elements that form acid soluble sulfides such as Cu, Ag, and Pb, enrichment of these elements might have been induced by the intense acid rain just after the end-Cretaceous asteroid impact.

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白垩纪末期撞击事件伴随海水中嗜硫元素的富集

来自丹麦Stevns Klint的白垩纪-古生界（KPg）边界粘土中富集了嗜碱性元素。由于Cu，Zn，Ga，As，Ag和Pb等几种嗜酸性元素中的Cu，Ag和Pb的浓度与Ir的浓度相关，因此我们建议将这些元素通过与白垩纪末小行星撞击。同步加速器X射线荧光图像显示，铜和银以微量元素的形式存在于黄铁矿晶粒中，或以1-10 µm大小的离散相形式存在，特别是富含铜或银。载体相的不同可能取决于将这些元素运输到海底的材料。根据它们与Cu，Ag和Ir的亲和力，氧化铁/氢氧化物和有机物被确定为将这些元素提供给海底的潜在载体相。吸附在氧化铁/氢氧化铁上的亲硫族元素可能在氧化铁/氢氧化铁的还原溶解过程中释放出来，并掺入到与氧化铁/氢氧化铁的还原溶解同时产生的黄铁矿中。撞击加热可能会从KPg目标岩石（即沉积岩和/或基底结晶岩）中释放出氧化铁/氢氧化物和亲硫元素，对有机物具有高亲和力的元素在降解后会被释放然后转化由于铁离子的缺乏而分解成离散的矿物。由于此类离散矿物包括形成酸溶性硫化物的元素，例如Cu，Ag和Pb，因此白垩纪末小行星撞击后的强烈酸雨可能已诱发了这些元素的富集。