Search the Community
Showing results for tags 'cretaceous extinction'.
-
From the album: Dinosaurs
K-Pg Boundary Microtektites Hell Creek Formation Garfield Co., MT, USA These aren't fossils, but are relevant to the extinction of the non-avian dinosaurs, pterosaurs, large marine reptiles, and many other species of flora/fauna at the end of the Cretaceous. When a large meteor/asteroid struck the earth ~ 66 mya, it sent molten ejecta across the world. Some of this molten material, sourced from the impact site, was shaped by its trajectory through the atmosphere and cooled into small, glassy droplets. The black blobs you see are those droplets, called tektites (each typically ~ 1 mm in diameter). The layer which these came from is more famous for its unusually high concentration of iridium (which is more common in meteorites than on Earth). However, in some locations, tektites have been preserved. In this matrix sample, I've also found carbonized plant material (charcoal), which suggests fires that could be associated with the impact event.- 8 comments
-
- 4
-
- cretaceous extinction
- dinosaur extinction
- (and 5 more)
-
Not the ones you eat. Mercury levels are high in late Cretaceous fossil shellfish. The shellfish can indicate sea temperatures with a special carbonate analysis too. So researchers can compare rising mercury from the Deccan Traps eruptions to rising temperatures at the same time. Surprisingly high levels of mercury contamination occurred. https://m.phys.org/news/2019-12-fossil-shells-reveal-global-mercury.html
- 5 replies
-
- 2
-
- climate records
- cretaceous extinction
- (and 2 more)