in 1980, scientists found that a certain layer of rock contained more than usual amounts of clay with the…

in 1980, scientists found that a certain layer of rock contained more than usual amounts of clay with the element iridium. scientists determined that the rock in this layer was about 65 million years old. an image of this rock layer is shown below. the scientists have also found the following three pieces of evidence. 1. evidence of dinosaur fossils were found in rock layers older than the iridium layer. 2. evidence of dinosaur fossils were not found in rock layers younger than the iridium layer. 3. iridium is not found in high concentrations in earth layers but is abundant in asteroids. what does this information most likely show about earths history and dinosaurs? a. a large asteroid collided with earth and helped dinosaurs thrive on earth. b. iridium was produced on earths surface by sedimentation and killed off the dinosaurs. c. iridium was produced on earths surface by sedimentation and helped dinosaurs thrive on earth. d. a large asteroid collided with earth and killed off the dinosaurs.

in 1980, scientists found that a certain layer of rock contained more than usual amounts of clay with the element iridium. scientists determined that the rock in this layer was about 65 million years old. an image of this rock layer is shown below. the scientists have also found the following three pieces of evidence. 1. evidence of dinosaur fossils were found in rock layers older than the iridium layer. 2. evidence of dinosaur fossils were not found in rock layers younger than the iridium layer. 3. iridium is not found in high concentrations in earth layers but is abundant in asteroids. what does this information most likely show about earths history and dinosaurs? a. a large asteroid collided with earth and helped dinosaurs thrive on earth. b. iridium was produced on earths surface by sedimentation and killed off the dinosaurs. c. iridium was produced on earths surface by sedimentation and helped dinosaurs thrive on earth. d. a large asteroid collided with earth and killed off the dinosaurs.

Answer

Explanation:

Step1: Analyze the evidence

Dinosaur fossils are not found in rock layers older than the iridium - rich layer and iridium is abundant in asteroids but not in Earth's layers.

Step2: Consider the implications

The presence of iridium in the clay layer and the absence of dinosaur fossils in older layers suggest a major event. A large asteroid collision can bring iridium to Earth and cause mass - extinction.

Answer:

A. A large asteroid collided with Earth and killed off the dinosaurs.