(Table T1) Iridium concentration in ODP Site 177-1090 sediments

Anomalous concentrations of Ir have been found in upper Eocene sediments from Ocean Drilling Program (ODP) Hole 1090B. Clear and dark-colored spherules that are believed to be microtektites and clinopyroxene-bearing microkrystites, respectively, were found in the samples with highest Ir. The peak Ir concentration in Sample 177-1090B-30X-5,105-106 (954 pg/g) and the net Ir fluence (14 ng/cm**2) at this site are higher than at most other localities except for Caribbean site RC9-58. The Ir anomaly and impact debris are probably correlative with similar deposits found at ODP Site 689 on the Maude Rise and at other localities around the world.