We meet the Cretaceous-Tertiary boundary in Mississippi

May 25th, 2010

STARKVILLE, MISSISSIPPI — George Phillips took us to a series of Starkville outcrops today straddling the Cretaceous-Tertiary boundary.  The boundary here is gradational and generally marked by a color change from gray in the upper Prairie Bluff Formation to light brown in the lower Clayton Formation.  Since we want to collect fossils just below and just above the boundary, these localities were ideal for us.

Megan Innis and George Phillips at the Cretaceous-Tertiary boundary in Starkville, Mississippi.

We were able to collect many encrusters and borings above and below this fateful event horizon.  I was most impressed by the diversity of encrusting foraminiferans on shells and phosphatic pebbles on both sides of the K/T, apparently showing little effects of the extinction.  A long time ago I did some systematic and paleoecological work with this group, so I may return to them to test these observations.

We also noted the proliferation of tiny oysters (especially Pycnodonte pulaskiensis) in the Clayton sediments immediately above the extinction horizon.  These are part of the initial survival and recovery fauna and thus keys to the future repopulation of this shallow marine ecosystem.

Small oysters in the lowermost Clayton Formation (Paleocene) in Starkville, Mississippi.

6 Responses to “We meet the Cretaceous-Tertiary boundary in Mississippi”

  1. […] the oysters are articulated (both valves still in place). The facies is very similar to that of the Paleocene Clayton Formation we saw earlier this summer in […]

  2. […] On Monday we will finish plant evolution with the remarkable angiosperms, and then we will look at the incredible story of the Cretaceous Mass Extinctions. The “Impact Hypothesis” was developed at the University of California, Berkeley, in 1980 when I was there as a graduate student (to my great fortune, even if I had nothing to do with it). It seemed a real stretch at the time, but now we know it as one of those intellectual breakthroughs which changed our perspective on the History of Life. The first website to visit, appropriately, is Berkeley’s Cretaceous Extinctions page — it has enough detail to keep us all busy. The Wikipedia page on the Cretaceous Extinctions is very good and kept updated by experts. In 2010 an Independent Study student, Megan Innis, and I had a great time at the Cretaceous-Paleogene boundary in Alabama and Mississippi. […]

  3. […] The story of the Cretaceous Mass Extinctions is amazing. The “Impact Hypothesis” was developed at the University of California, Berkeley, in 1980 when I was there as a graduate student (to my great fortune, even if I had nothing to do with it). It seemed a real stretch at the time, but now we know it as one of those intellectual breakthroughs which changed our perspective on the History of Life. The first website to visit, appropriately, is Berkeley’s Cretaceous Extinctions page — it has enough detail to keep us all busy. The Wikipedia page on the Cretaceous Extinctions is very good and kept updated by experts. In 2010 an Independent Study student (Megan Innis) and I had a great time at the Cretaceous-Paleogene boundary in Alabama and Mississippi. […]

  4. […] The story of the Cretaceous Mass Extinctions is amazing. The “Impact Hypothesis” was developed at the University of California, Berkeley, in 1980 when I was there as a graduate student (to my great fortune, even if I had nothing to do with it). It seemed a real stretch at the time, but now we know it as one of those intellectual breakthroughs which changed our perspective on the History of Life. The first website to visit, appropriately, is Berkeley’s Cretaceous Extinctions page — it has enough detail to keep us all busy. The Wikipedia page on the Cretaceous Extinctions is very good and kept updated by experts. In 2010 an Independent Study student (Megan Innis) and I had a great time at the Cretaceous-Paleogene boundary in Alabama and Mississippi. […]

  5. […] The story of the Cretaceous Mass Extinctions is amazing. The “Impact Hypothesis” was developed at the University of California, Berkeley, in 1980 when I was there as a graduate student (to my great fortune, even if I had nothing to do with it). It seemed a real stretch at the time, but now we know it as one of those intellectual breakthroughs which changed our perspective on the History of Life. The first website to visit, appropriately, is Berkeley’s Cretaceous Extinctions page — it has enough detail to keep us all busy. The Wikipedia page on the Cretaceous Extinctions is very good and kept updated by experts. In 2010 an Independent Study student (Megan Innis) and I had a great time at the Cretaceous-Paleogene boundary in Alabama and Mississippi. […]

  6. […] The story of the Cretaceous Mass Extinctions is amazing. The “Impact Hypothesis” was developed at the University of California, Berkeley, in 1980 when I was there as a graduate student (to my great fortune, even if I had nothing to do with it). It seemed a real stretch at the time, but now we know it as one of those intellectual breakthroughs which changed our perspective on the History of Life. The first website to visit, appropriately, is Berkeley’s Cretaceous Extinctions page — it has enough detail to keep us all busy. The Wikipedia page on the Cretaceous Extinctions is very good and kept updated by experts. In 2010 an Independent Study student (Megan Innis) and I had a great time at the Cretaceous-Paleogene boundary in Alabama and Mississippi. […]

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