mu-Synchrotron radiation excited X-ray fluorescence microprobe trace element studies on spherules of the Cretaceous/Tertiary boundary transitions of NE-Mexico and Haiti samples

摘要

Synchrotron radiation,collimated to a um scale was used for the determination of trace elements in micro-tektites and spherule material for the first time.The experimental set-up of the SXRF microprobe at beamline L at HASYLAB at DESY offers a suitable method for performing non-destructive in situ multi-element analysis focusing on spatial trace element distributions and mineral phases of the melted ejecta material from the Cretaceous/Tertiary boundary.The spatial distribution of trace elements was determined in melt inclusions as well as in phase transitions in selected parts of chlorite-smectite spherules and tektite glass material by using a beam with a diameter of 15 um collimated with a glass capillary for line-and area scans as well as for single point measurements for elements with Z between 19 and 92.The analyzed spherules show alteration features but also zonation and carbonate inclusions,originating from the Chicxulub impact event.These initial results demonstrate the potential of mu-SXRF analysis for the discrimination of alteration and primary signals of the spherules and re-construction of their genetic evolution.It could be shown that the spherules represent a complex mixture of different materials from the subsurface at the Chicxulub impact site.