Talk:Morrison Formation

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[edit] Corrected dating of the end of deposition of the Morrison Formation

If the Morrison Formation is dated from 155 Ma to 147 Ma then it must have ended at 147 Ma not 155 Ma. Also the NPS website (http://www.nps.gov/archive/dino/morrison.htm) for Dinosaur National Monument states that deposition ended 147 Ma. The NPS site also says that the unconformity lasted 15 Ma to 20 Ma not 30 Ma. Dr. Morbius 00:38, 27 May 2007 (UTC)

Oldest radiometric age: 156.3 + 2 Ma (TRUJILLO, K.C., K. R. CHAMBERLAIN, and A. STRICKLAND. 2006. Oxfordian U/Pb ages from SHRIMP analysis for the Upper Jurassic Morrison Formation of southeastern Wyoming with implications for biostratigraphic correlations. Geological Society of America Abstracts with Programs, 38(6): 7). Youngest age: 146.8+1 Ma (Bilbey, S.A. 1998. Cleveland-Lloyd Dinosaur Quarry - age, stratigraphy and depositional environments. Pp. 87-120, in The Morrison Formation: An Interdisciplinary Study (K. Carpenter, D. Chure, and J.I. Kirkland, eds.). Modern Geology, 22.)Anky-man 00:43, 22 October 2007 (UTC) —Preceding unsigned comment added by Anky-man (talk • contribs)

Now added - thank you! J. Spencer 04:47, 22 October 2007 (UTC)