Enigmatic late Cretaceous high palaeo-latitude lonestones in Chukotka, northeasternmost Asia

• Published in: GFF
• Main Authors: Ahlberg, A., Herman, A.B., Raikevich, M., Rees, P.M., Spicer, R.A.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: 2002
• Subjects: Chukotka
• Online Access: https://oro.open.ac.uk/5041/; http://www.gff-online.se/site/article.asp?articleID=784

Well-rounded cobbles were encountered within a low-energy restricted marine organic-rich deposit of latest Cretaceous age in Chukotka, NE Asia. The clasts are hydrodynamically incompatible with the inferred quiet depositional environment of the host sediment. Driftwood capable of tree-rafting, glacial striations, gastrolith clast clustering, and disrupting clast impact impressions typical of volcanic ejecta were absent, as were signs of traction currents. If indeed ice-rafting is responsible, this supports recent climate models and palaeobotanical data which favour seasonal marine ice cover of high northern latitudes over a wide span of boundary conditions.