Sunday, May 1, 2011

Bridge or Arch?

While the terms "natural bridge" and "natural arch" are often used interchangeably, geologists usually make a distinction.

Rainbow Bridge
 The term "bridge" is usually used to indicate a span that has been eroded by a stream running through it.
Double Arch
Arches are also formed by water but by the freezing and thawing and chemical weathering of water.

Linked to Sunday Bridges, hosted for us by Louis at San Francisco Daily Photo.

11 comments:

LauraX said...

These are so beautiful Martha...thanks for explaining the geological distinctions between bridges and arches.

Yogi♪♪♪ said...

Double bonus. Got to see some nice pics and got a geology lesson.

EG Wow said...

New to me! You're correct that bridges and arches DO look the same but I like knowing why they are different.

Carly said...

absolutely beautiful! I love the vibrant colors!

Crafty Green Poet said...

beautiful photos and thanks for the definitions!

Gary said...

Which ever it's pretty impressive. Boom & Gary of the Vermilon River, Canada.

Genie said...

What fine captures, Martha. I love the geology lesson. I had never thought about the formations that way. So very interesting. I get so excited when I see a thumbnail showing the copper colored rock formation because I immediately know I am going to get to see something from out west. These are beautiful shots.

ρομπερτ said...

How very impressive !

Please have you all a good new month and week as well.

daily athens

Janie said...

Thanks for clearing that up. I've heard the definitions before, but I had forgotten.
Nice photos!

Sallie (FullTime-Life) said...

I haven't done a bridge post in forever, but I'm betting that this is the most beautiful post on that meme! Thanks for the explanation.

Pat said...

I learned something new today--the difference between a natural bridge and a natural arch. Interesting.