The nature of the Chicxulub projectile and its distribution in the crater nd in the proximal and distal ejecta deposits: Trace element concentrations in impactites, target rocks, and potential meteoritic impactors (asteroids)

将对国际综合开发项目“希克苏鲁布科学钻探项目”的2.5公里深的岩芯和约200公里大小的希克苏鲁布撞击结构的其他地层进行研究，以便通过测量撞击熔化的目标岩石中可能被射弹“污染”的“陨石”元素的丰度，重建撞击物的性质及其在撞击过程中的命运。这将通过ICP-质谱结合NiS火分析程序对铂族（PGE）和其他亲铁元素进行分析，并通过补充XRF和INAA分析主要和微量元素来实现。将开展两个平行的次级项目：（1）“陨石特征”在撞击坑内连贯的撞击熔融岩石、苏埃云岩角砾岩和空气降落沉积物中以及在近端和远端喷出物沉积物中的分布和分布，包括K/T边界粘土，以及撞击后分馏过程引起的这一特征的蚀变效应（结晶，热液蚀变，成岩作用），和-由于陨石数据库不足-（2）PGE和其他亲铁元素丰度（和主要元素组成）的主要集团和亚集团的石质陨石（陨石，无球粒陨石）。通过对这两组数据的综合和解释，我们预计将得出希克苏鲁布撞击事件中射弹的成分和撞击条件（撞击角度/速度）的估计值。这些结果对于更好地了解地球上的撞击过程具有普遍重要性。

The 2.5 km deep drill core of the ICDP "Chicxulub Scientific Drilling Project" and other formations of the ~200 km sized Chicxulub impact structure will be studied in order to reconstruct the nature of the impactor and its fate during impact by measuring the abundance of "meteoritic" elements in impact melted target rocks which are presumably "contaminated" by the projectile. This will be achieved by ICP-mass spectrometry combined with NiS fire assay procedure for the Platin Group (PGE) and other siderophile elements and by supplementary XRF and INAA analyses for major and trace elements. Two parallel subprojects will be pursued: (1) Abundance and distribution of the "meteoritic signature" in coherent impact melt rocks, suevite breccias and air fall deposits within the crater and in the proximal and distal ejecta deposits including the K/T boundary clay, and alteration effects of this signature induced by post-impact fractionation processes (crystallization, hydrothermal alteration, diagenesis), and - because of an insufficient meteorite database - (2) PGE and other siderophile element abundances (and major element composition) of the main groups and subgroups of stony meteorites (chondrites, achondrites). From the synthesis and interpretation of both data sets we expect to derive the composition of the projectile and estimates of the impact conditions (angle/velocity of impact) at the Chicxulub impact event. The results will be of general importance for a better understanding of impact processes on Earth.