Ukrainian Asteroid impact craters could be part explain the extinction of dinosaurs about 65 million years Ukrainian Asteroid impact craters could be part explain the extinction of dinosaurs about 65 million years.
Several impact craters are in Ukraine, but their ages ranging between 350 and 65 million years. Thus, these craters are evidence of asteroid impacts over time hitting the Earth long ago. However, these craters plays an important role in understanding the frequency of asteroid impacts on Earth, as well as understanding the critical K / T boundary layer and associated with our geological history.
At least two impact craters identified in Ukraine appear to be related to the age of mass extinction on earth happened around 65 million years. This is the age of the K / T is all over the world as well.
We will now discuss some of the craters, and begins with the best describes them, the Impact Crater Boltysh.
The crater is a crater Boltysh impact of Kirovohrad Oblast province of Ukraine.
The crater is 24 km in diameter and age of 65.17 ± 0.64 million years, based on argon dating techniques, the error is in the Chicxulub crater in Mexico, and the boundary KT. The Chicxulub impact is believed to have caused the mass extinction at the end of the Cretaceous era, which included the extinction of dinosaurs.
Boltysh and several other impact craters around the world have estimated ages of about 65 million years, leading to the idea that the Earth was struck by multiple asteroid impacts at this time. The collision of Comet Shoemaker-Levy 9 with Jupiter in 1994 showed that these multiple impacts on several days are possible.
Boltysh crater is located in central Ukraine in the basin of the river Tiasmyn River, a tributary of the Dnieper. It is 24 km in diameter, surrounded by a blanket of ejected breccia preserved over an area of 6500 sq. km. It is estimated that immediately after the impact, ejecta covered an area of 25,000 km ² and a depth of 1 m or more, and about 600 m deep at the crater rim. The crater is not visible on satellite images because it is part of agricultural land today and covered with sediment.
The crater contains a central uplift at about 6 km in diameter, from about 550 m above the base level of the crater. The uprising is now under about 500 m of sediment deposited since the impact, and was discovered in the 1960s during oil exploration.
When first identified, the age of the crater can not be forced roughly between the ages of rocks affected (the target) and the age of overlying sediments. The deadline for the rocks (Cenomanian 98.9 to 93,500,000 years) and Turonian (93.5 to 89 million years) periods. sediment samples covering the crater Boron containing fossils dating from the Paleocene epoch, 65 to 54.8 million years ago. The age of the crater was thus forced between 54.8 and 98.9 million years.
After radiometric dating reduces uncertainty. The concentration of uranium-238 decay products in the glasses of the impact crater were used to calculate the age of 65.04 ± 1.10 million years. Analysis of argon radioactive decay products yielded an age of 65.17 ± 0.64 million years.
Posted on April 9, 2010.
