Popigai impact structure

Popigai impact structure

• Located in northern Siberia, Russia
• Fourth largest verified impact structure on Earth
• Created by a large bolide impact approximately 35 million years ago
• Possible link to the Eocene-Oligocene extinction event
• Designated as a Geopark by UNESCO

Diamond deposits

• Popigai diamonds are about 1 mm in size and consist of nanodiamond agglomerates
• The diamond deposits have not been mined due to the remote location and lack of infrastructure
• Many of the diamonds contain crystalline lonsdaleite, an allotrope of carbon with a hexagonal lattice
• Laboratory-created lonsdaleite is up to 58% harder than ordinary diamonds
• Carbon polymorphs, a combination of diamond and lonsdaleite, have been discovered in the crater

Impact craters on Earth

• Popigai is one of the many impact craters on Earth
• List of impact craters provides information on other known impact sites
• List of possible impact structures includes potential impact sites yet to be confirmed
• Logancha crater is another notable impact crater
• Understanding impact craters helps in studying Earth's geological history

References

• Earth Impact Database provides information on impact structures worldwide
• 'Popigai Crater: General Geology' by Victor L. Masaitis is a comprehensive resource on the Popigai impact structure
• 'Establishing the link between the Chesapeake Bay impact structure and the North American tektite strewn field: The Sr-Nd isotopic evidence' by Alexander Deutsch and Christian Koeberl explores the connection between different impact structures
• 'U-Pb Analysis of zircons from the Popigai impact structure, Russia: First Results' by Richard Armstrong, S. Vishnevsky, and C. Koeberl discusses the analysis of zircons in the Popigai crater
• 'Popigai, Siberia—well preserved giant impact structure, national treasury, and world's geological heritage' by Alexander Deutsch, V.L. Masaitis, F. Langenhorst, and R.A.F. Grieve provides insights into the significance of the Popigai impact structure

Properties of impact diamonds

• Popigai diamonds are unsuitable as gems but may have industrial uses
• Diamond deposits at Popigai are unlikely to be competitive with synthetic diamonds
• Impact diamonds are formed when a meteorite strikes a graphite deposit at high velocity
• Impact diamonds inherited the tabular shape and delicate striations from the original graphite grains
• 'Harder than Diamond: Superior Indentation Strength of Wurtzite BN and Lonsdaleite' by Zicheng Pan, Hong Sun, Yi Zhang, and Changfeng Chen discusses the exceptional hardness of lonsdaleite

Popigai impact structure Data Sources