question 2 of 10\nwhich observation in a rock layer would provide scientists with evidence that a mass…

question 2 of 10\nwhich observation in a rock layer would provide scientists with evidence that a mass extinction event had occurred?\na. a gradual shift in the structures of fossilized organisms and the levels of uranium isotopes\nb. a rapid change in the features of fossilized species, and the discovery of new isotopes in fossils\nc. fossilized structures that are similar to those found in current organisms\nd. high levels of iridium (a metal found in asteroids) and a sudden lack of fossils of many species

question 2 of 10\nwhich observation in a rock layer would provide scientists with evidence that a mass extinction event had occurred?\na. a gradual shift in the structures of fossilized organisms and the levels of uranium isotopes\nb. a rapid change in the features of fossilized species, and the discovery of new isotopes in fossils\nc. fossilized structures that are similar to those found in current organisms\nd. high levels of iridium (a metal found in asteroids) and a sudden lack of fossils of many species

Answer

Brief Explanations:

A mass - extinction is a sudden decrease in biodiversity. Iridium is rare on Earth's surface but abundant in asteroids. High levels of iridium can indicate an asteroid impact, which is often associated with mass - extinctions. A sudden lack of fossils of many species also points to a mass - extinction event.

Answer:

D. High levels of iridium (a metal found in asteroids) and a sudden lack of fossils of many species