Finding old dry riverbeds

[A#1]

I've been scanning over USGS 7.5 minute topo maps, looking for old, now dry riverbeds. I ain't really found much.

Anyone got any pointers on locating them? How would you do it?

 

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[OwenT]

I think Lidar would be helpful. The images are like topo maps, but have better definition when it comes to small changes in elevation under tree cover. There's a thread about it right now on this same forum. It can defenitely be helpful to see old benches up above the river that have vegetation on them now.

 

[arizau]

Just come out to Arizona, they are everywhere...... Boots on the ground looking for out of place river rocks. Ma Nature has covered them up or relocated them so most likely no geological techniques to predict them other than by observation(?).

Good luck.

 

[rodoconnor]

Just drive . Look at road cuts . Ancient riverbeds are everywhere. If you are in gold country and can locate an ancient riverbed underneath a lava flow-CHA CHING\

 

[Bejay]

It all depends on where you are looking (state by state) and understanding some of the Geology of the area you are interested in . Az is all together different from Mich. There are all kinds of ancient riverbeds,


Bejay

 

[et1955]

I think Lidar would be helpful. The images are like topo maps, but have better definition when it comes to small changes in elevation under tree cover. There's a thread about it right now on this same forum. It can defenitely be helpful to see old benches up above the river that have vegetation on them now.

So true Owen, do recognize this area ?

 

[OwenT]

So true Owen, do recognize this area ?View attachment 1673768

You know that's the first place I looked when that link got posted

 

[et1955]

You know that's the first place I looked when that link got posted

I wonder why. LOL

 

[ExcuseToHike]

This is an example of a large ancient river bed that can be seen via Lidar.




Here is the same area but on a regular map.

 

[OwenT]

Excusetohike, where in WA do you live?

 

[ExcuseToHike]

Snoqualmie area.

 

[ExcuseToHike]

I've been scanning over USGS 7.5 minute topo maps, looking for old, now dry riverbeds. I ain't really found much.

Anyone got any pointers on locating them? How would you do it?

I hunted around for a while for Michigan area Lidar maps but did not find any that I really liked. You might have better luck but even without them if you know what to look for you can see the ancient river beds on topographical map. You might have the best luck if you look on the inside bends just like you would in a regular river. I am admittedly still a n00b at prospecting but others here might be able to confirm or refute this.

 

[et1955]

I hunted around for a while for Michigan area Lidar maps but did not find any that I really liked. You might have better luck but even without them if you know what to look for you can see the ancient river beds on topographical map. You might have the best luck if you look on the inside bends just like you would in a regular river. I am admittedly still a n00b at prospecting but others here might be able to confirm or refute this.

Lidar maps are another great tool for us to use, pic 1 and 2 are of the same area, google earth and lidar Topo maps lack definition and detail.

 

[russau]

If I'm not mistaken that area was on public t.v. awhile back and it was created from a ancient Ice dam that was 2 miles (?) tall and backed up a massive lake ....it eventually broke open and gorged out that valley that went to the west. While that was going on the massive flow of water /ice created "pot holes" in the rock floor of that valley!

 

[russau]

In the Keene catalog, a listing of gold books and such there is a book titled "Lost River of gold" .GREAT READ!! but it also talked of a MASSIVE River that flowed north from the Mammoth MTn. area that flowed from Southern cal. to Alaska and it also branched off east to the Mississippi River.I did a little research and viewed maps and it appeared to me that it flowed through Kansas. Would'nt that be a find of a life time!!