Geology in pictures – meanders and oxbow lakes

I love meandering rivers. This is a short post with some (I think) great images  of meandering rivers and oxbow lakes.

In my previous post Google Earth and a 5 minute book review: Geology illustrated I reviewed one of my favorite coffee table books: Geology Illustrated by John S. Shelton.

The last view in that post was as close a perspective replica of Figure 137 in the book as I could get using Google Earth, showing the meander belt of the Animas River a few miles from Durango, Colorado.

What a great opportunity to create a short time lapse: a repeat snapshots of the same landscape nearly 50 years apart. This is priceless: 50 years are in many cases next to nothing in geological terms, and yet there are already some significant differences in the meanders in the two images, which I have included together below.


Meander belt and floodplain of the Animas River a few miles from Durango, Colorado. From Geology Illustrated, John S. Shelton, 1966. Copyright of the University of Washington Libraries, Special Collections (John Shelton Collection, Shelton 2679).

Meander belt and floodplain of the Animas River as above, as viewed on Google Earth in 2013.

For example, it looks like the meander cutoff in the lower left portion of the image had likely ‘just’ happened in the 60s, whereas at the time the imagery used by Google Earth was acquired, the remnant oxbow lake seems more clearly defined. Another oxbow lake in the center has nearly disappeared, perhaps in part due to human activity.

Below are two pictures of the Fraser River in the Robson Valley that I took in the summer of 2013 during a hike to McBride Peak. This is an awesome example of oxbow lake. We can still see where the river used to run previous to the jump.



And this is a great illustration (from Infographic illustrations) showing how these oxbow lakes are created. I love the hands-on feel…ox-bow-lake-infographic

The last is an image of tight meander loop from a previous post: Some photos of Northern British Columbia wildlife and geology.



Geology photo quiz #1

Take a look at the photo below, which I took it on the way up to McBride Peak (in McBride, British Columbia). It is a view up the Sunbeam Creek, part of an Ecological Reserve. Question: why would (only) part of the creek be so white? My father-in-law and I had been wondering since a previous hike to the top of the Peak, and speculations were running rampant. Finally, yesterday, we decided to hike up to the top again, then go down to the creek to find out. I think we did, and it was a great hike and a lot of fun. I am in the process of writing a nice post on this geo-adventure, but I though in the meantime I’d post the photo and make it a quiz.


I will give readers two clues:

1) the mysterious white “stuff” sits in a creek where water is actually running;

2) this is a south face, exposed to the sun all day long, so it couldn’t be snow or ice.

Below is a close-up photo. So, what do you think it is?
Or at least, what do you think it could be?