Ahlberg, A.; Herman, A.B.; Raikevich, M.; Rees, P.M. and Spicer, R.A.
Enigmatic late Cretaceous high palaeo-latitude lonestones in Chukotka, northeasternmost Asia.
GFF, 124(4) pp. 197–199.
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.
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