Depth of Old Coins

[togamac]

I went to a fairground parking lot this afternoon for a couple of hours. Didn't find anything worth writing home about but wanted to ask you old timers a question. This parking lot has been in use for about 75 years. I know that there has to be silver in it. How deep do you think the old stuff is what with all the seaons in between and rain, mud, snow, grass mown. etc? I was digging clad at about 2-8 inches. Is our AT's capable of reaching the old stuff? What's the best way to find out? I'd like to be smarter the next time I go back.

 

[Mark652]

Togamac, I think you will find the AT Pro will find those older coins at depths of up to about 9-10 inches comfortably. I have been searching an area that has been maintained as mostly cared-for grass and old trees since the late 1700s never with agriculture so little or no fertilizer was used on these grounds. The grounds have not been turned over much or, most importantly, had top soil or additional landscaping done over it. I am describing this to highlight that lost coins are being found in layers, the older the coin the deeper it is being found. I and several of my friends have been detecting this site and we are finding coins from about the early 1900s to the late 50s between 3-5 inches deep, coins from the Civil War to around 1900 around 6 inches deep and older coins between 6-9 inches deep. I found a silver half dollar from 1901 at about 6 inches deep and a large cent dated 1820 around 9 inches. My oldest coin so far, a 1799 large cent was about 10 inches down. The AT Pro is detecting these coins, but the deeper ones are giving off faint signals in my headphones. The signals are clear and repeatable, but faint. I am operating in Pro mode in All Metal. I have not found any coins deeper, or the AT Pro is not picking them up deeper, I am not certain which, but I have the benefit of the ground also being pretty clean so if something is deeper I feel confident the AT Pro will detect it. I have found a couple of bullets around 10-12 inches deep and I was pretty impressed when I opened the holes to see how deep I had to dig. I also found a half dime at about 7 inches depth. The half dime is a very small and thin coin. The At Pro picked it up and the signal was pretty faint. Good luck, Mark

 

[John-Edmonton]

Gravel? clay? sand? Mineralization amount?

 

[Jason in TN]

You never know. Have dug silver coins from signal and it is laying on top of the ground a tree root that has pushed it up down to a foot or deeper.

Jason

 

[togamac]

Thanks for the very informative reply Mark. BTW, nice finds! I guess I just need to go slow and listen for those deep and faint tones. I was hunting in Pro custom with iron audio on, sensitivity at 5 notches and discrimination at 30. GB was around 87.

John from Edmonton asked what the parking lot composition is. Based on my digging yesterday John it's just an old hay field. The soil is a nice mixture of clay and sand; easy to dig in the parking spaces, not so easy in the "roadways". The one problem I did run across was the the shredded remains of aluminum cans left by the mower but was able to ID many of those without digging after awhile. Thanks for your replies guys,

HH, Mac

 

[Jerry-Wi]

Depth of coins is something I probably will not ever figure out. Here are a few examples why:

Last spring I was in an old park with huge amounts of trash. Got a very shallow quarter hit and popped it out with the screw driver thinking that it was clad. Turns out to be a 1943 silver quarter in very nice shape. (No, I did not put a mark on it )

This past Saturday I dug a 1923 Merc at about six inches in very dry clay. About a foot away I got another deep signal only for a Zinc penny, so thinking Indianhead
penny I dug it. It was nearly as deep at the Merc. dime and it was a Zinc penny. Same soil, same location. Go Figure!

Also During the month of May, I found three war nickels all at different baseball fields that have been around forever. I only had to actually dig for one of them as it was about 4 inches deep. The other two were barely below the sod.

I know there has to be a reason for why coins are as deep as you find them, but I just do not know what that is.

Jerry

 

[togamac]

Thanks for the reply Jerry. It took me back to my Air Force days. I was in EOD and part of our training consisted of digging shafts for recovery of unexploded bombs. I was flabbergasted to learn that a 500lb bomb dropped from an airplane will penetrate about 6 feet of sand and about 125 feet of clay. Ever try to dig in solid clay? It ain't easy. Gravity doesn't discriminate so I would guess that if you're digging in sandy soil, coins will be closer to the surface and if you're digging in clay fagetaboutit! Which means, by the way, that the coins in my fairground parking lot should not be too deep. Can't wait to go back and do some slow and deliberate searching. That 20 acre parking lot may take awhile!
Thanks, mac

 

[Big Boys Hobbies]

The AT Pro will smoke coins at that depth. If they are there it will find them!

 

[GoGoGopher]

Most of the time, canslaw comes up as 40-42 for me on the AT pro...larger can parts come up anywhere from 65-85, but will hold the pinpoint with the coil a foot off the ground...
Most of the silver around me is 7-10 inches deep at least, but you get surprised every now and then with a 4 inch silver

HH,

 

[togamac]

Thanks Gopher. I was digging the small canslaw because I've found a couple of rings in the past at 42ish. The Propointer helped me out with the large stuff - if it's 6 inches wide in a parking lot it ain't getting dug! Also found a few pulltabs, they rang in at a solid 62 but I dig'em anyways just in case.
HH, Mac

 

[tmanly]

Soil content and location will often cause targets to sink faster or slower. If on a hilltop, targets will often be shallow. If in a lower area where water can stand, targets will sink deeper and faster. If you are finding clad coins at 6 or 7 inches then the good stuff will be 12" or more. Try digging all signals to clear the site, one small area at a time. Then you can go " all metal" with high sensitivity and you may be able to pull some of the deeper targets out. turn volume up and listen for those faint signals. If you start to dig and then loose the target, dig deeper. Often you are reading a target that is deep because of the halo that is created. when you dig, you disturb the halo and it will go away, just dig deeper and recheck. Just look at the grass , if it is dark and thick, then the targets will be deep. Plus on a fair ground where a lot of traffic is present will cause targets to work a little deeper until the soild is packed hard.

Tom in SC

 

[murfar1]

I think in addition to the type of soil and condition as mentioned above, the coin density might also come into play. Here's some of them:

Gold 19.3
Silver 10.5
Copper 9.0
Aluminum 2.7
Lead 11.4
Steel 7.8
Zinc 7.1
Iron 7.87

Given the same soil conditions,and length of time in the soil, the coin density of a wheatie (copper) would cause it to sink deeper than one of the infamous zinclon cents. A gold coin is going to be down yet further. Soil conditions are also a major factor; i.e. ground which gets a lot of saturation will move coins deeper and faster as tmanly pointed out.

 

[togamac]

Thanks Tom. That's good information about looking at the grass - I never thought of that. I think when I go back I'll concentrate on a small patch like you suggest maybe in a dryer section of lot and see what happens. I'll let you'all know.
Mac

 

[Metal Magnet]

tmanly's advice, as well as others, is sound. different ground/locations have different sink rates. Getting a feel for the sink rates of different areas is very very helpful. note the dates/eras of things you are digging and the depth. This helps map an area. I have dug indian heads at 2 inches and clad at 8. It just depends on how the ground was changed, soil composition, mineralization, etc.

Good question.

 

[maxxkatt]

remember some silver coins do get dropped out of pockets at a much later date. My friend found a barber dime on the surface of a soccer field. Kid must have snitched it from his dad's coins.