What Caused the Mass Extinction Recorded at the K-T Boundary?
ESU801  The K-T Layer
Richard P. Walker, Shawn T. Smith, and Steven M. Smith, USGS
The K-T boundary layer in Caravaca, Spain.

3. What is significant about the discovery of iridium at the K-T boundary?

 


	

 	

		
			
	

	
	

		 
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