THE DYNAMIC EARTH: A BLOG ABOUT GEOLOGY AND THE EARTH SCIENCES

Sunday, December 6, 2009

The Return of Sunday Sed Structures!

A substantial hiatus between "Sunday Sed Structures", perhaps, but seeing as how I'm a fan of the ol' Sed/Strat side of things, I reckon it's perfectly acceptably for me to engage in hiatuses of all sorts (as well as terrible pun-based stratigraphy humor). Below is a picture from the Holiest of Holies, The Book Cliffs!


A pretty big piece of float, perhaps, but it illustrates the elusive and complex 3-Dimensional nature of bedforms rather nicely, I think. On the right-hand face of the boulder, you can see the more traditional trough cross-stratification, oriented roughly parallel to flow. On the left-hand face, you can see the troughs themselves; this view is roughly perpendicular to flow, and preserves the scoop-like trough that is the cross-stratification's namesake. Just goes to show you that when dealing with trough cross-stratification and paleocurrent orientation, you gotta be careful, and TRY to find some nice 3-D (or, more likely, the good ol' 2-and-a-half-D) exposure.

No comments: