Figure 2 - Distribution of extraterrestrial (chondritic) chromite and osmium isotopes through Middle Ordovician sections in Sweden and China.

From the following article

Asteroid breakup linked to the Great Ordovician Biodiversification Event

Birger Schmitz, David A. T. Harper, Bernhard Peucker-Ehrenbrink, Svend Stouge, Carl Alwmark, Anders Cronholm, Stig M. Bergström, Mario Tassinari & Wang Xiaofeng

Nature Geoscience 1, 49 - 53 (2008) Published online: 16 December 2007


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Results are shown for sections at Kinnekulle (Hällekis and Thorsberg quarries) and southern Scania (Killeröd and Fågelsång sections), 350 km apart in southern Sweden, and the Puxi River and Fenxiang sections, 4 km apart in south-central China. The distribution of Os isotopes across the Hällekis section is also shown. The stratigraphic interval yielding abundant fossil meteorites in the Thorsberg quarry is indicated6. The conodont biostratigraphy shown has been produced specifically for this study, using consistent taxonomic concepts for the different sections. M. ozarkodella=Microzarkodinaozarkodella.