Vegetation patterns for ancient channels in aerial or satellite photos

[Xplore]

Anyone know what type of vegetation patters to look for in aerial or satellite photos when trying to find where ancient channels may be intersecting present rivers or creeks cross wise?

Would the vegetation be more dense or less dense? Why?

Are there any other patterns I should look for besides a difference in vegetation? For example, would the overburden look different?

Starting to comb through potential claim locations so I want to add the possibility of ancient channels to our hypotheses for each location.

Would appreciate any insights or specific examples of places where GPEX members could see examples of where ancient channels intersect (and ideally links to photos). 

Cheers,

Xplore

[suburbanator]

Anyone know what type of vegetation patters to look for in aerial or satellite photos when trying to find where ancient channels may be intersecting present rivers or creeks cross wise?

Would the vegetation be more dense or less dense? Why?


Xplore

Have a look at the vegetation type you see up  where you were just working,   where the pipeline work was done etc.     That type of re-growth is typical also of old channels.   Photo attached is a great example.

So less dense,  different type of trees.....

Vertical light green path is an old rail line,  the horizontal is a steep but dry old river channel.   It only gets water at extreme run off,  and yet its a 20' deep canyon.

Not sure if that is is what your looking for.

[Brad F]

Look for photos taken in the fall. For example, cottonwoods, poplar etc. , leaved trees give it away with their orange color. These trees love water. When you see a stand of them well above river level even 1000 ft. there's a reason that their still growing. Horsetail root is another indicator, you'd be surprised what I find in these areas. McBain saw it 1st hand on the Fraser when we were digging nowhere near the river, but rather up in the grass.

[Xplore]

Thanks Chad and Brad, that's some great info!

-Xplore

[the gold guy]

A lot of times you will find birch or poplar instead of evergreens were an old channel might be.

[mcbain]

Was talking to a Gal from the caibou the other day.She told me they really concentrate on where the willows grow.Down here we have very little willow but cottonwood can be a good indicator.Luck,Mcbain.

[Brad F]

Further more, I believe I said earlier in this post a 1000 feet up from a current flowing drainage I've seen a stand of deciduous trees mixed in with evergreens, I met up with CMMC one day a while ago and pointed out a stand way the hell up a mountain to him and his buddy, near mountain tops in  a particular drainage. What are cottonwoods doing way up there?  I laugh when my old neighbor who lived 3km away from me said "Ya know, if you did an assay on this horsetail root it would show traces of gold", he was right......

[mcbain]

Good post Brad.Abit of trivia most tend to forget,Gold travels down to the creek/river bottom it does not come up to the creek bottom unless the creek is eroding away ancient deposits and even then it is not coming up.the creek is simply going deeper.Hope that makes some sense.Luck,Mcbain.

[JOE S (INDY)]

Other than availability of water there is yet another factor - fresh soil.

Where the surface is disturbed - from a former streambed, road cut, mining operation, avalanche area or even a fire clearing, the bare soil will naturally replant itself with whatever seeds happen to fall on it.  Often that soil will replant with the lightest airborne seeds which include (in my area) willow and black balsam. 

Having reseeded the fresh soil the species of trees or vegetation will (or could be) very different than the usual mix of plant life.  Ground water and mineralization also have an effect but what grows in those formerly bare patches of soil may well not be 'the norm'.

One last factor to differing vegetation is an unusual winter with deep snow drifts, followed by cool summers.  Under the snow vegetation will die off and wherever there is bare ground ...........

Joe

[Shrewdly]

You might find the following link helpful.

Shrewdly



https://www.for.gov.bc.ca/hfd/pubs/Docs/Mr/Scanned-Rn/Rn034-Rn066/Rn066A.pdf