Sentences with phrase «iridium anomalies»

There is substantial evidence (iridium anomalies, craters, and shattered quartz fragments) to support such theories and there is good reason to believe that such an impact could create conditions (shock waves, tsunamis, forest fires, acid rain, darkness lasting months or years, global cooling or warming) to eliminate a large portion of the world's species.

The strata from this time shows an iridium anomaly (up to 285 parts per trillion) and a fern spore spike, suggesting that a bolide impact was the cause.