Large river rocks in California gravel bar triggering signal, what are these?

firebird

Full Member
Oct 17, 2018
229
310
Central Valley California
Primary Interest:
All Treasure Hunting
I went metal detecting for the first time today with a cheap metal detector in Briceburg near Yosemite, along the Merced river. Didn't find anything interesting aside from trash but it does work. One odd thing I noticed though is that some large rocks are also producing a signal, like that biggest rock here at the bottom of the picture. Wasn't able to get a closer picture, but it's just a large, dark colored rock that didn't look particularly special but was really heavy and large, only a sledgehammer would be able to break it open.

IMAG0668.jpg

Why would it be producing a signal, are these rocks full of iron concentrations large enough to set off the metal detector? I spend my time here just panning for gold instead since there are small flakes here and there but there's also a huge amount of black iron sand.
 

Upvote 1

dognose

Silver Member
Apr 15, 2009
2,908
7,834
Indiana
Detector(s) used
Fisher F70
Dont know about the rock.

That is a beautify location.

Did you find any gold?
 

galenrog

Bronze Member
Feb 19, 2006
2,013
2,192
Many rocks contain detectable metal ores. One of the most common is iron. These are commonly referred to by detectorists as “hot rocks”.

Time for more coffee.
 

pat-tekker-cat

Gold Member
Feb 23, 2011
6,335
8,486
S. Fl.
🏆 Honorable Mentions:
1
Detector(s) used
Minelab Excal II, Garrett, Tesoro
Primary Interest:
All Treasure Hunting
Was just going to say, "hot rocks".

They were all over Bondi Bch, Au, too, :BangHead:
very frustrating little boogers...

I'd double check it with the sledgehammer, though,
just to be sure.... :laughing7:

GL & HH.... (yes, a beautiful looking location)...
 

OP
OP
F

firebird

Full Member
Oct 17, 2018
229
310
Central Valley California
Primary Interest:
All Treasure Hunting
Thanks for the info, I have much to learn from metal detecting still, just got it this Christmas as a present. There is gold here but only really tiny flakes in the gravel, it just seems to be a waste of time metal detecting since the gold seems to come from all the way in Yosemite and just grinds down to tiny pieces that a metal detector can't find. Here's a nice overhead view of the area here.

 

A2coins

Gold Member
Dec 20, 2015
33,807
42,606
Ann Arbor
🏆 Honorable Mentions:
3
Detector(s) used
Equinox 800
Primary Interest:
All Treasure Hunting
What reading did your detecor give
 

A2coins

Gold Member
Dec 20, 2015
33,807
42,606
Ann Arbor
🏆 Honorable Mentions:
3
Detector(s) used
Equinox 800
Primary Interest:
All Treasure Hunting
Welcome from Mi. Tommy
 

pat-tekker-cat

Gold Member
Feb 23, 2011
6,335
8,486
S. Fl.
🏆 Honorable Mentions:
1
Detector(s) used
Minelab Excal II, Garrett, Tesoro
Primary Interest:
All Treasure Hunting
You may get more info out of the prospectors section/sub-thread.
I mine gold, too, just in a different manner, opposite coast... :laughing7:
I'm usually scratching around in a litter box. :cat:

Them hard core prospectors would prolly laugh
at anything us beach fellas tell ya. :laughing7:

I did run across this today (on fb).
That's about my level of panning/sluicing/etc... :-\
Even though I don't speak the language,
I can see what they're saying.... :laughing7:

It is for learning sake, (somewhat)informative, none the less.
And cute... :laughing7:

https://www.facebook.com/goldlineor...8WNYj5BVlfMnVdg51MIDFuR6zzgqtfTLS02pYDAYwESWy
 

Tanneyhill

Jr. Member
Mar 5, 2023
93
91
Thanks for the info, I have much to learn from metal detecting still, just got it this Christmas as a present. There is gold here but only really tiny flakes in the gravel, it just seems to be a waste of time metal detecting since the gold seems to come from all the way in Yosemite and just grinds down to tiny pieces that a metal detector can't find. Here's a nice overhead view of the area here.


Go for a hike upstream Merced and the creeks that flow into it if you are interested in big nuggets.
 

Top Member Reactions

Users who are viewing this thread

Top