The Cretaceous Extinction

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The Cretaceous Extinction

There are many therioes and ideas on what caused the Cretaceous extinction but I’m going to focus more on the asteriod theory. Some therioes include: volcanic activity, an exploding supernova, and starvation etc. and I will cover them but mainly on the asteriod theory. The reason is because the asteriod theory is the most common and in my opinion one of the most logical. It’s still a tough decision but hopefully in the future we will eventually discover what caused the extinction.
About 65 million years ago, at the end of the Cretaceous period, a large fraction of plant and animal families suddenly went extinct. In this Cretaceous-Tertiary or K-T mass extinction (K is for Kreide, meaning chalk in German, which describes the chalky sediment layer from that time. T is for Tertiary which was the next geologic period), all land animals over about 55 pounds went extinct. Later on the smaller organisms began to fade away too. Leading up to the mass extinction, most of the dinosaurs went extinct before the mass extinction at the end of the Cretaceous period. This catatrosphic event led to the Age of Mammals.
There are a lot of theories about why this K-T (Cretaceous-Tertiary) extinction occurred, but the most accepted theory was proposed in 1981 by physicist Luis Alvarez and his son Walter Alvarez. These geologists believed that an asteroid 4-9 miles (6-15 km) in diameter hit the Earth about 65 million years ago. The impact would have penetrated the Earth's crust, scattering dust and debris into the atmosphere, and causing huge fires, tsunamis, severe storms with high windsand highly acidic rain , seismic activity, and maybe even volcanic activity. The dust and debris thrust into the atmosphere would have blocked most of the sunlight for months, and lowered the temperature globally. This impact could have caused chemical changes in the Earth's atmosphere, increasing concentrations of sulfuric acid, nitric...