![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
. | ![]() |
. |
![]() by Staff Writers Paris, France (SPX) Nov 25, 2016
The fall of an asteroid in the Yucatan Peninsula (Mexico) 66 million years ago is believed to have caused the extinction of dinosaurs. It also created the Chicxulub impact crater, the only such crater on Earth that still has a peak ring - a type of structure commonly found, in contrast, on the surface of several objects in the Solar System. As a result, and despite the crater being buried under several hundred meters of sediment, scientists the world over will do anything to uncover its secrets. The IODP/ICDP Expedition 364, carried out by an international team1 of researchers from the CNRS, Aix-Marseille Universite and the Universite de Bourgogne, has published its initial findings in the 18 November 2016 edition of Science: for the first time, 835 metres of collected core samples will reveal how rock formations occurred while this type of crater developed. IODP/ICDP Expedition 364 began with two months of offshore drilling between April and May 2016 on board the L/B Myrtle. Shallow water drilling during this first phase of the mission allowed scientists to collect 303 core samples (sediments and impactites2) of excellent quality, and nearly 6 km of accumulated well data. This data was analyzed by an international team of around 30 scientists, four of whom work for French laboratories: the first to unearth the rocks that form the peak ring of an impact crater. This is the first time the peak ring of a meteorite crater has been drilled. A peak ring is a circular structure of often irregular hills located inside a large crater. Frequently observed on the surfaces of silicated bodies in the Solar System, including the Moon, Mercury and Venus, these topographical structures are the subject of considerable debate as to how they formed, and, until now, had never been sampled. Researchers observed that the peak ring is predominantly made up of granitic rock (combined with molten rock) which, in addition to being shocked, was shifted several kilometres towards the surface during impact. These rocks are also cross-cut by shear zones. Analysis shows that impact generated vertical fluxes and increased porosity in planetary crust. The type of rocks that form the peak ring on the Chicxulub crater and their physical characteristics confirm the 'dynamic collapse' model of peak-ring formation. These results are the first in a long series that will partially lift the veil on this type of crater, from the role it plays in the geology of the planets to its impact on climate. Researchers also hope to determine whether ancient or more recent types of microbial life were able to grow in the rocks of the peak ring.
![]() ![]()
Related Links CNRS Asteroid and Comet Mission News, Science and Technology
|
|
The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us. |