Fujii Posted February 16, 2015 Share Posted February 16, 2015 I am studying geology. I could not identify K-Pg boundary within this picture. http://en.wikipedia.org/wiki/Cretaceous%E2%80%93Paleogene_boundary#mediaviewer/File:KT_boundary_054.jpg In addition, I have visited Horseshoe canyon, but is it possible to find T-Pg boundary in this picture? https://29b39c5a-a-62cb3a1a-s-sites.googlegroups.com/site/fkazumichi/home/english-fujii-kazumichi/Horseshoe%20formation.jpg?attachauth=ANoY7co1OJjZTF5XzOgS3an-tzNpf0UaK7ewt3I9fXKkNzQ277O3zaurGJru6nMwOsuqOzUMe7m3Ztslf795NdZRKcCcVJ7jiUV18K9MQtOar3ucC19o1lCPiGIJL22LKL-wRm-A3qbm4RkCeIFXHaPb2EVn3ap0G3b1pHFSVXy90zLMqgt4tXhTiLK7MOz-qxds3Zt0CPGeZQXuwdHS2-CR1auCDyPsi6UW4iYlbkxQbKMLkXjFaORoU0LWEG2PiXGDuYcfGk9V3XlBVU7L2IoecWvRMEL1Tw%3D%3D&attredirects=0 Thank you for your kindness. Link to post Share on other sites
jpc Posted February 16, 2015 Share Posted February 16, 2015 The K/T boundary is not easy to see, at least in the Hell Creek Fm, which is wht your two pix are. It is NOT an obvious layer. I don't know about marine rocks in DK, NZ, IT and others. You have to take samples of rock everywhere between the highest dinosaur bone you can find, and the lowest Paleocene mammals. Then look for an abnormally high amount of iridium in it. It is a lot of work done by specialists. This is why there are only a few documented sites (in terrestrial deposits). I think both of the photos you found are of generalized shots of the Hell Creek Fm... "Where the boundary has been found". Meaning that they could not find a photo of the boundary and stuck these Hell Creek pix in there. Does that make sense? Link to post Share on other sites
jpc Posted February 16, 2015 Share Posted February 16, 2015 Additionally, I have stood at the boundary in Wyoming, with these very same specialists who did the work, and it is still not obvious. One factor is that is is only about a cm thick and in the Lance and Hell Creek Fm's, every time it rains and when snow melts, the top layers of mudstone just melt away a bit, so the actual surface shown in your pix is "blurry" with last week's rain made mud, so at this scale the 1 cm thick layer will not show up. Does that make sense? Link to post Share on other sites
Fujii Posted February 16, 2015 Author Share Posted February 16, 2015 Thank you very much for answering. The first picture is shown in wikipedia as representative photo of K-Pg boundary, but no arrow indicated the layer. http://en.wikipedia.org/wiki/Cretaceous%E2%80%93Paleogene_boundary I hope this will be improved. Link to post Share on other sites
Missourian Posted February 16, 2015 Share Posted February 16, 2015 (edited) It's possible the iridium layer is not present at the location. Some of the Cretaceous beds could have eroded away before the Paleocene sediment was deposited. Edited February 16, 2015 by Missourian Link to post Share on other sites
Troodon Posted February 16, 2015 Share Posted February 16, 2015 On the web page that you Thank you very much for answering. The first picture is shown in wikipedia as representative photo of K-Pg boundary, but no arrow indicated the layer. http://en.wikipedia.org/wiki/CretaceousPaleogene_boundary I hope this will be improved. On that web page they do mark the layer on a picture lower in the page. On the image you asked about my guess is that the layer is at the junction between the light and dark area. I say that because I found the attached image on the web which is identical to the one you were asking about just flipped. Link to post Share on other sites
Fujii Posted February 17, 2015 Author Share Posted February 17, 2015 Thank you for indicating the boundary, it is highly informative to non-experts. Link to post Share on other sites
Fujii Posted February 18, 2015 Author Share Posted February 18, 2015 Link to post Share on other sites
Fujii Posted February 18, 2015 Author Share Posted February 18, 2015 It was red deer river vallery. Link to post Share on other sites
Stocksdale Posted February 20, 2015 Share Posted February 20, 2015 This video was really good about the k/pg boundary. https://www.hhmi.org/biointeractive/day-mesozoic-died Link to post Share on other sites
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now