What is the theory that an impact event lead to the extinction of the dinosaurs?

Answer 1

There are over 50 different theories to the extinction of the dinosaurs. One of the current favorites is the “deep impact” theory proposed by the geologist Walter Alvarez in about 1980. This theory states that a meteor strike caused dramatic climate changes much like a “nuclear winter” which supposedly caused the extinction of the dinosaurs and many other animals. His evidence was his discovery of an alleged world-wide layer of clay with a high iridium content, which is found in meteorites.

Well, there are plenty of papers that talk about the problems with this theory. One, is that the earth’s core also has iridium in it that can be brought up by volcanoes. Many Creationists believe Noah's Flood would have caused the greatest volcanoes that there have ever been, and some believe God pelted the earth with meteors during the Flood as well.

Answer 2

The mass extinction bringing the end of dinosaurs, marine reptiles, and many other terrestrial and marine organisms marks the end of the Cretaceous. This extinction event occured rapidly about 65 million years ago.

The hypothesis supported by the most evidence is the "impact theory," proposed and articulated by Louis and Walter Alvarez and colleagues. We think that a meteorite large enough to be called a small asteroid hit the earth near the Yucatan Pennisula. This caused a series of dramatic and rapid changes to the environment, including a change in temperature and pH of the ocean, and a darkening of the sky by all the dust particulates thrown up into the atmosphere by the impact. These changes probably limited solar radiation, reducing the diversity and biomass of photosynthetic primary producers, causing the demise of organisms in other trophic groups (like plant-eating dinos and meat-eating dinos).

The evidence supporting this hypothesis is strong. First, there is a layer of iridium you can find at all places where rocks show the K-T boundary. Iridium, which is extremely rare on earth, is abundant in meteorites. Second, shocked quartz, which is formed by the large amounts of energy with impacts, is also abundant in rocks of this age, especially in North America. There are other geologic and fossil data that support this hypothesis.

Answer 3

About 65 million years ago at the end of the Cretaceous a large bollide impact is thought to have occurred on Earth. The rock record shows an Iridium spike at this time which is associated with meteor impacts. There is a also large crater shape around the Gulf of Mexico that is thought to be the impact site.

When something like that happens, it triggers world wide seismic activity. Which means volcanoes all over the planet start to erupt. When this happens lots of gasses and dust are thrown into the air blocking out the sun. When the sun is blocked, plants die. When plants die herbivores die and when herbivores die carnivores die.

Not all the dinos went extinct though. Many Saurischians lived and evolved into our modern day birds.

Answer 4

A large meteor hit the earth, putting tons and tons of dust in the sky, blocking out the sun. Without sunlight, all the plants die. Without plants, all the herbivores die, without herbivores, all the carnivores die.

There's a lot more to it than that, but that's the basic theory.

Answer 5

comet hit the earth