Just as literature students develop the craft of analyzing the structure of a story, so do geologists analyze the structures of sediments and the stories that they tell. The internal architecture of sand bodies is endlessly varied, fascinatingly complex, and, if we can only figure out what it's trying to tell us, hugely informative. Revealed are sagas of currents, ancient and modern, of rivers and beaches, barrier islands, deltas and sand bars that sculpt the earth's surface today or did so hundreds of millions of years ago.
Several items on sedimentary structures have cropped up recently, and so this is a kind of short miscellany on the theme. Andrew Alden has just launched a gallery of sedimentary structures on About Geology (http://geology.about.com/od/geoprocesses/ig/sedstrucs/). Brian at Clastic Detritus has posted a couple of exquisite photos of plane- and ripple-laminated sandstones. Steve Gough at Riparian Rap recently noted that Google Maps contains some high-resolution aerial photos and point us to examples along the Mississippi ( http://lrrd.blogspot.com/2009/06/high-resolution-aerials-of-mississippi.html). These are truly spectacular, and I have reproduced below an image of the beautiful bedforms in a point bar.
And, for animated excitement, go to Dave Rubin and Carissa Carter's page at the USGS where they have numerous videos of extraordinary computer-modelled sedimentary structures in action - the whole site is worth spending some time on, but I've always been entranced by the animations.
Blogs are so informative where we get lots of information on any topic. Nice job keep it up!!
Posted by: Masters Dissertation | November 07, 2009 at 08:07 AM
its a great pictures of sands. They are very naturally beautiful.
Posted by: Donald | May 16, 2011 at 01:25 PM