Which best supports the evidence that an asteroid collision may have caused caused the extinction of dinosaurs? (1 point)
O Rare metal on Earth called Iridium is found in layers where dinosaurs disappeared.
O Bodies of dinosaurs are only found in craters where asteroid collided.
O Dinosaur fossil remains are found at the bottom of a body of water.
O Many dinosaur skeletons are found in one particular rock layer.
The answer that best supports the evidence that an asteroid collision may have caused the extinction of dinosaurs is:
- Rare metal on Earth called Iridium is found in layers where dinosaurs disappeared.
This is because the presence of iridium in the same layers where dinosaur fossils disappear suggests a connection between the asteroid collision and the extinction event. Iridium is found in high concentrations in asteroids, so its presence on Earth could be a result of an asteroid impact.
The option that best supports the evidence that an asteroid collision may have caused the extinction of dinosaurs is:
- Rare metal on Earth called Iridium is found in layers where dinosaurs disappeared.
The option that best supports the evidence that an asteroid collision may have caused the extinction of dinosaurs is:
- Rare metal on Earth called Iridium is found in layers where dinosaurs disappeared.
To understand why this is the case, let's break it down:
Iridium is a rare element found on Earth but is more abundant in extraterrestrial objects like meteorites and asteroids. In the 1980s, scientists discovered a worldwide layer of clay that marked the boundary between the Cretaceous and Paleogene periods, which is also known as the K-Pg boundary. Above this boundary, dinosaur fossils became scarce.
The discovery revealed that this layer contained a significantly higher concentration of iridium compared to other layers. This anomaly and the global extent of the iridium-rich layer pointed to an extraterrestrial source. Scientists then hypothesized that an asteroid collision could have caused this widespread deposition of iridium.
Further investigations led to the discovery of the Chicxulub crater, buried under Mexico's Yucatan Peninsula. This crater was dated to be from the same time period as the K-Pg boundary and was estimated to be about 200 kilometers in diameter. The impact released an enormous amount of energy and would have had catastrophic effects.
While the other options mentioned—finding dinosaur remains in craters, at the bottom of a body of water, or in a particular rock layer—might have their own individual significance in paleontological studies, they do not specifically provide evidence supporting the hypothesis of an asteroid collision causing the extinction of dinosaurs.
In conclusion, the discovery of high concentrations of iridium in the K-Pg boundary layer strongly supports the theory that an asteroid collision led to the extinction of dinosaurs.