any one framiliar with the san juan river in utah...?

Question

on the upper river are there crinoid fossils on some of the rocks? i went on a school trip last may and I am interested to investigate them. thank ya

Answer 1

I'm not sure of the level of investigation you're after. Nice website to get you started on crinoids as fossils: http://www.geol.umd.edu/~tholtz/G331/lectures/331echin1.html

You will be able to get closer to identifying the types of crinoids that you found if you can locate yourself correctly in "time". Crinoids are a fairly common fossil in many formations in Utah because shallow seas invaded the area many times.
Start with a geologic map of the area and try to locate approximately where you collected the fossils--remembering that the river probably cuts down through many formations. The Utah Geological Survey website has lots of links: http://geology.utah.gov/maps/geomap/index.htm
Do you remember which formation you collected them from or what it looked like? There are lots of description online of the rock formations of the Colorado Plateau. Get started here: http://3dparks.wr.usgs.gov/coloradoplateau/ And then, perhaps, click on Glen Canyon for a discussion of stratigraphy in southern Utah.

Answer 2

I'm not sure of the type of fossils of which you speak, but I'm sure they're there.

I went on a kayaking trip through there, to the lake/dam. Went about 80 miles on it or so.

I was in school and had a rad biology teacher, who was also a kayaking teacher. Well, anyway i remember an expedition we took, crawling up through the cliffs and ravines on the sides of the river.

You have several layers of fossil deposits. All of which are clearly visible.

Small streams crawl towards the river. The cliffs, reddish and sandstone like (not good with geology however), are carved by the water. There are numerous pools. Clear, cold water flows slowly through a gallery of fossils. There are even some petroglyphs.

We found a species of algae we couldn't recognize--it was really weird looking.

Often, in out of the way places--like Utah or Colorado in roadless areas--you'll find species 200,000 years old or older. They exist untouched, breeding throughout the seasons.

Go there if you get a chance. It's the best place ever for a fossil hound. Or if you're into native american history. awesome.

But for the fossils: everything you want to see. Respect the burial grounds tho.