Lunkhead asked:
"I'm confused about this (from an earlier post). A little help?"
A figure showing where the K/T Boundary iridium layer has been found can be seen in "Cretaceous-Tertiary (K/T) boundary" at:
http://www.geo.vu.nl/~smit/ktboundary/K_Tboundary.htmlhttp://www.geo.vu.nl/~smit/ktboundary/65Maworldmap.gif
This web page has links to pages describing and illustrating the actual K/T boundary at a number of locations, including:
1. AGOST (K/T) page
http://www.geo.vu.nl/~smit/betics/Agost/agostkt.htmhttp://www.geo.vu.nl/~smit/betics/Agost/agost.jpghttp://www.geo.vu.nl/~smit/betics/Agost/Ir13C18OAgost.jpghttp://www.geo.vu.nl/~smit/betics/Agost/AgostForabund.jpg
2. The Barranco del Gredero, near Caravaca, Provincia de Murcia, Espana
http://www.geo.vu.nl/~smit/betics/Caravaca/caravaca.htm
3. A "map of the Gulf of Mexico and Caribbean sea 65 million years ago" showing the locations of modern outcrops of the impact deposits at:
http://www.geo.vu.nl/~smit/ktboundary/gulf_caribbean.htm
II. An interesting paper is "Calcareous nannofossil biostratigraphy and
palaeoecology across the Cretaceous/Tertiary boundary on the
Brazilian eastern coast" by Alexandre Grassi, Seirin Shimabukuro
in INA88th International Nannoplankton Association Conference.
http://www-user.uni-bremen.de/~micropal/abstr_g06.html
Look at the figure of the stratigraphic distribution of foraminfera at the K/T boundary in Brazil at:
http://www-user.uni-bremen.de/~micropal/abstr_g06_1.jpg
Compared this figure to the figure showing the stratigraphic distribution of formanifera at Agostat at:
http://www.geo.vu.nl/~smit/betics/Agost/AgostForabund.jpg
Some more pictures of the K/T boundary in"Spanish Peaks & KT Boundary" at:
Page not found - Laboratory for Atmospheric and Space Physics
III. More about the K/T iridium anomaly can be found in "THE IRIDIUM ANOMALY AT THE K-T BOUNDARY" at:
http://www.scn.org/~bh162/iridium.html
Some web pages about the K/T boundary within the Hell Creek Formation are:
I. The K-T Boundary In The Hell Creek Formation
http://www.scn.org/~bh162/k-t_boundary.html
II. Hells Creek, Wyoming boundary layer is indicated at:
http://www.hcc.hawaii.edu/~pine/Phil100/ktlarge.html
III. South Dakota Mesozoic Era Formations
Lost... | South Dakota State University
IV. K/T acid rain, leached paleosols and the "barren zone"
(Was: mammals over dinosaurs in...)
Page Not Found | Cleveland Museum of Natural History
Some Hell Creek publications:
Fastovsky, D. E., 1987, Paleoenviroments of vertebrate-
bearing strata during the Cretaceus-Paleogene transition,
eastern Montana and western North Dakota. Palaios.
vol. 2, pp. 282-295.
Fastovsky, D. E., and R. H. Dott, Jr., 1986, Sedimentology,
stratigraphy, and extinctions during the Cretaceous-
Paleogene transition at Bug Creek, Montana. Geology.
vol . 14, pp. 279-282.
Fastovsky, D. E., K. McSweeney, and L. D. Norton, 1989,
Pedogenic devlopment at the Cretaceous-Tertiary boundary,
Garfield County, Montana. Journal of Sedimentary Petrology.
vol. 59, pp. 758-767.
Retallack, G. J., G. D. Leahy, and M. D. Spoon, 1987,
Evidence from paleosols for ecosystem changes across
the Cretaceous-Tertiary boundary in Montana. Geology.
vol. 15, pp. 1090-1093.
Retallack, G. J., 1994, A pedotype approach to latest
Cretaceous and earliest Tertiary paleosols in eastern
Montana. Bulletin of the Geological Society of America.
vol. 106, pp. 1377-1397.
Retallack, G. J., 1996, Acid Trauma at the Cretaceous-
Tertiary Boundary in eastern Montana. G.S.A. Today.
vol. 6, no. 5, pp. 1-7.
Other Hell Creek Formation - K/T boundary references can be found in "The K-T Extinction Boundary: Selected Primary Scientific References" at:
http://www.scn.org/~bh162/extinction_refs.html
Yours,
Bill