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A New “Golden Spike” Monument in Colorado Marks Geologic Time 
Andrew Alden [source] | October 31, 2013

For something that is supposed to keep track of 4 billion years of history, the geologic time scale is quite a fuzzy and slippery yardstick. After two centuries of careful research and argumentation, the world’s geologists have only recently adopted a system to literally nail down the different time periods taught in geology school.

Last week that project took another slow step forward as a “golden spike” was officially driven into a precise spot on the ground near Pueblo, Colorado, a benchmark for the beginning of the Turonian Age.

The Turonian is, in the ICS’ geologic timescale, the second age in the Late Cretaceous epoch, or a stage in the Upper Cretaceous series. It spans the time between 93.5 ± 0.8 Ma and 89.3 ± 1 Ma (million years ago).   [Wikipedia]

The Western Interior Seaway then divided North America into eastern and western halves; Appalachia and Laramidia.

24 million years after the Turonian ended, a massive asteroid struck the Yucatan, spelling the end for the dinosaurs.

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[1] Photo courtesy Brad Sageman 
[2] Ichthyornis by S.V.Naugolnyh 
[3] Cover to American Journal of Botany, 89(12), 2002, showing leaf and pinecone litter on a Turonian Coastal Plain forest floor with the oldest unequivocal fossil monocot
[4] Zuniceratops by cheungchungtat
[5] The Turonian Stratotype Section near Pueblo, Colorado. Photos courtesy Bob Kay
[6] J of Sedimentary Research [X]  
[7] Chronostratigraphic chart

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    Goldent Spike - Turonian
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