Chicxulub crater

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Gravity anomaly map of the Chicxulub impact structure. The coastline is shown as a white line. A striking series of concentric features reveals the location of the crater. White dots represent water-filled sinkholes in the limestone rocks of the region

The Chicxulub crater is a very big crater. Some scientists believe that the Chicxulub crater was made by the meteor that caused the extinction of the dinosaurs, and many other animals. It is partly in the Yucatán Peninsula in Mexico and partly underwater.

The Chicxulub crater is more than 180 km (110 mi) in diameter, making it the third largest confirmed impact crater.[1] Petroleum prospectors found it in the late 1970s.

The bolide which formed the crater was at least 10 km (6 mi) in diameter. Evidence for the impact origin of the crater includes shocked quartz, a gravity anomaly, and tektites in surrounding areas. The age of the rocks and isotope analysis show that this impact structure dates from the end of the Cretaceous period, roughly 66 million years ago. The impact associated with the crater is implicated in causing the extinction of the dinosaurs.

A 2007 study suggested that the bolide may have been a piece of a much larger asteroid that broke up in a collision and also produced 298 Baptistina, 160 million years ago.[2] The results of this study were disproven in 2011 using data from the Wide-field Infrared Survey Explorer (WISE). This data revised the date of the collision which created the Baptistina family to about 80 million years ago.

In March 2010, following analysis of the available evidence covering 20 years' worth of data in the fields of palaeontology, geochemistry, climate modelling, geophysics and sedimentology, 41 international experts from 33 institutions reviewed available evidence. They said the impact at Chicxulub triggered the mass extinctions during the K-T boundary, including that of dinosaurs.[3][4]

Scientists can now describe in detail how the asteroid that wiped out the dinosaurs produced its huge crater.[5] The reconstruction of the event 66 million years ago was made possible by drilling into the remnant bowl and analysing its rocks.

Evidence of impact[change | change source]

Scientists have found evidence of fallout from the asteroid impact. Excavations in North Dakota reveal fossils of fish and trees that were sprayed with rocky, glassy fragments that fell from the sky. The deposits also show evidence of being swamped with water. This was caused by the colossal sea surge caused by the impact.[6]

Related pages[change | change source]

References[change | change source]

  1. Earth Impact Data Base
  2. Bottke W.F; Vokrouhlicky D. & Nesvorny D. (2007). "An asteroid breakup 160 myr ago as the probable source of the K/T impactor" (PDF). Nature. 449 (7158): 23–25. doi:10.1038/nature06070. PMID 17805288. Retrieved 2007-10-03.CS1 maint: multiple names: authors list (link)
  3. Schulte, Peter; et al. (2010). "The Chicxulub asteroid impact and mass extinction at the Cretaceous–Paleogene boundary". Science. AAAS. 327 (5970): 1214–1218. doi:10.1126/science.1177265. ISSN 1095-9203. PMID 20203042. Retrieved 5 March 2010.
  4. Rincon, Paul (2010-03-04). "Dinosaur extinction link to crater confirmed". BBC. Retrieved 2010-03-05.
  5. Amos, Jonathan 2019. Asteroid strike made 'instant Himalayas'. BBC News Science & Environment. [1]
  6. Amos, Jonathan 2019. Chicxulub asteroid impact: stunning fossils record dinosaurs' demise. BBC News & Environment. [2]