The detection of the iridium enrichment in the KT boundary clay layer first led to the meteoritic impact hypothesis as a possible cause of the dinosaur extinction. The determination of PGE elemental ratios in impactites can contribute to the identification of the type of impacted meteorite. See ...
Iridium is a hard, brittle, corrosion-resistant metal with the symbol77Ir. It is one of the platinum group elements (or PGE) – ruthenium, rhodium, palladium, rhenium, osmium, iridium, and platinum – which are highly siderophilic and form strong bonds with iron. Most of the terrestrial PG...
When exposed to air, it reacts with oxygen to form a thin Layer of iridium dioxide (IrO 2 ). At high temperatures, the metal becomes more reactive. Then it reacts with oxygen and halogens to form iridium dioxide and iridium trihalides. For example: ...
Sixty five million years ago, the Cretaceous–Paleogene (K–Pg) extinction event occurred, and marked the loss of 70% of the plant and animal species on Earth including all non-avian dinosaurs. The geological record is marked by the K–Pg boundary, a thin layer of sediment, which was ...
Since L. Alvarez first found the iridium anomaly at the Cretaceous/Tertiary (K/T) boundary layer and proposed an extraterrestrial impact model to interpret the dinosaur extinction, a number of researchers studied over 100 K/T boundaries in the world. However, until now little work on dinosaur ...
The detection of the iridium enrichment in the KT boundary clay layer first led to the meteoritic impact hypothesis as a possible cause of the dinosaur extinction. The determination of PGE elemental ratios in impactites can contribute to the identification of the type of impacted meteorite. See ...
(ca. 200–500 ppb). Elevated PGE concentrations measured in terrestrial rocks indicate a meteoritic contribution. The detection of the iridium enrichment in theKT boundaryclay layer first led to the meteoritic impact hypothesis as a possible cause of the dinosaur extinction. The determination of PGE...
In the early 1980s Alvarez and his father publicized Walter’s discovery of a worldwide layer of clay that contains a high level of the rare-earth element iridium, which is common only deep within Earth’s mantle and in extraterrestrial rocks. This layer was deposited at or near the Cretace...