The Chinle Formation: a river flowed through it

Petrified Forest National Park at sunset; photo by NRiggs

Funding available!!

Several years ago a popular movie called "A River Runs Through It" showed the beauty of Montana rivers and told a story about a fisherman (who apparently in real life was an awful crank). When I published a paper in 1996 in Science about deciphering the Upper Triassic Chinle river system I was interviewed by an AP reporter, who sent out a wire story called A River Flowed Through It. It was my 15 minutes of fame. The science is very cool.

I recently received an NSF grant to study the relation between Mesozoic sedimentary rocks on the Colorado Plateau, in western Arizona and eastern California, in southern Arizona, and in Sonora, Mexico, to earliest volcanic activity along the western margin of North America (I am working with colleagues at Indiana University Purdue and University of Kansas). We are looking at volcanic detritus in all the sedimentary units and characterizing it however possible - through geochemistry of clasts, finding the ages of the clasts, detrital-zircon studies, etc. We are also working more on fingerprinting the likely source volcanic and plutonic material in eastern California and western Nevada. In the process, we will provide information about the isotopic age of units in the Mesozoic sedimentary rocks. In the case of the Chinle Formation, this includes rocks that have dinosaur remains.

We also will want to find out as much as possible about the depositional environments of the units. Ultimately, we'll want to put together a tectonic map of North America that shows where the volcanoes were, where the rivers were, and where the basins were.

If you have an interest in tectonics/sedimentology/geochemistry/petrology, there is probably a thesis for you in this project...

Click here to get a reprint of the Science paper about a possible connection between "headwaters" of the Chinle river and its mouth in Nevada, based on analysis of detrital zircons.

Click here to get a reprint of the Geol. Soc. America Bulletin paper about the isotopic age of one of Black Forest Bed (upper part of the Chinle Formation at Petrified Forest Park).


Zircon crystals from the Black Forest Bed,
Petrified Forest Member, Chinle Formation