If only I could.......

If only I could scrape off the top 12" of the Earth's top-soil........... then let every detectorist go detecting 3 times (3 days). The educational "lessons-learned" would be:

1) There's just as many targets in the 12" - 24" depth strata.... as in the 0" - 12" strata.
2) The targets are more valuable.
3) Sink-rates are much worse than perceived/imagined.
4) This "hobby" just became quite "professional/serious".
5) Discoveries would be made in areas whereby no known activity was historically documented; subsequently re-writing history.
.............. and a host of other valuable reasons.

Now........... if you live in a town that was created in 1958....... there may be very little below the depth of 12". But........ if you (for instance) live in one of the New England States where your town was platted in 1746......... your educational experience would be an experience that you would never forget. Then........... after about 6 months (giving you plenty of time for your experience.... and thoughts to process/materialize/organize) ..... scrape off the 12" - 24" depth strata........... now opening your detecting experience in the 24" - 36" depth strata.

If this sounds crazy/unfounded............. go have a talk with an Archaeologist.

NASA-Tom --

I would love to take 8" of soil off of my favorite park...I feel pretty confident that I have removed most of the remaining, detectable (non-masked) coins -- particularly in small areas where I've focused, from this park. I'd love to do it in 2" increments -- to see how many targets were contained in each two-inch layer but were masked so as to be undetectable; then, after all layers were removed, to re-detect the area and see just how many coins lie deeper than the 8" mark.

On one hand, my brain says that the reason 8 to 9 inches is as deep as I find coins routinely, is CLEARLY due to the depth limitations of detectors, in my dirt. I know this is PART of the equation. However, on the other hand, the dense red clay in this part of the country ALSO makes me wonder just how much deeper targets can "sink." Aside from the coins which end up deeper due to "dirt work" having been done over the years, I'd love to see what lies beyond 8" in areas where the dirt has remained undisturbed. I have found a few dozen late 1800s/early 1900s coins in the 5-10" layer in this park, and with the town I live in dating back only to the 1889 Oklahoma land run (and this particular park dating back to 1891), it is clear, based on what I've found, that at least some of the oldest coins available have been hindered from sinking beyond detection depth...

Bottom line is, in this particular park, in this particular type of soil, it would be truly educational -- in a potential "epiphany" kind of way -- to see what lies deeper than 8" here...

Steve

For this reasoning anytime dirt is moved hit it quick before the other guy does...is the way to go..

Sort of been there done that and probably best summer I ever had when they took 8-10 inches off a high school baseball field that was once old site of amusement park and turn of the century meeting grounds. Between my buddy and I uncovered over 100 silver coins back to Barber, hand full of Indian head pennies, mason jar full of wheaties.
In the mix coins up to 8-9 inches were recovered so I feel before the renovation coins were in the ground 16-18 inches deep just too deep for even a CZ.
Another instance was when the dikes were ripped apart and renovated large cents and even two English half pennies from the 1700's were recovered by the local club.
So again when dirt is moved you know the drill...and be quick as most towns have more than a few members of the hobby and they know the drill also...

The town where i live Petersburg, Illinois was the cause of death of New Salem now a state park. I have heard it said that New Salem would have just been another hedgerow/cornfield if Abe Lincoln didn't live there. What is in that field or down that old tree line? Nasa Tom sanitized any ballfields lately? What depth would you lose those wonderful pull-tabs?

Very well put.
I have heard it said that ..."there are more coins still lost underground than what are currently in circulation today." The key word is "circulation".

This "sink" word has got me confused. On some of the other forums some of your so called experts say coins don't sink but they can't explain how they get to the depths that they do.I think it is the earths movements,freezing ,thawing and just the natural evolving of the earth and density of different soils but maybe I'am way of base too. One so called expert says a solid can't pass thru another solid so the physics rules out coins sinking? I know a solid can't pass thru a solid but I think there is more to it.
I believe coins do sink for what ever reason and that there are a boat load of them out of our reach. I just need Tom to give us all a good explanation on how this really happens.
Corey.

One of my most productive spots dates back 500 years. I have pulled some silver coins that look like new from there (1678). The land hasn't been plowed in many many many years. I sometimes see a farmer there cutting the grass and have now vowed to beg him to plow that meadow deeply, should we cross paths again! When I went back there with my CTX after hitting it heavy with my T-Trac, I did find 2 coins that were deeper than prior, but know there must be just tons of coins down there deep (as the land was an old market). I found a very thin dime sized coin 8" down there and then found some heavier coins 2"-3" deep that were 100's of years old. They are all mixed down there due to a variety of factors (perhaps plowing in the past, though none of the coins bear no damage from plowing.)

I just want a detector that can get down 12" reliably with disc. Any deeper and it would be hard to dig to be honest. I think many of us, due to our ground, can only get down 8"-9". An extra 3" would do wonder. But 12"! Wow.

Nice thread, there is hope for those hunted out spots.
Albert

Soil is not really a solid mass like bedrock. You can penetrate it. A simple way to think of it would be to look at a kids gym with the big ball pit. All of it together looks like one solid mass but it's made up of tiny dirt pieces.That's how things "sink". I believe the scientific term is "stratify" instead of sink rate. Gold panning is an excellent example of it on a small scale. As you shake the pan, the heavy objects go to the bottom and stop when they hit the pan...and then you use the power of the water to move the lighter material out of the pan until all you're left with are the heavy objects....black sand and gold.

My favorite sites to hunt are demos. When things where booming around here, there was a big building torn down in the city of Stockton, Ca. City dates to beginning of the gold rush, and this was right at the center of where it started. At first not much dirt was scraped, and thus not much good was found. Then I saw they scraped down about a foot. One of my buddies didn't even want to hit it because he thought they went to deep. We did detect it, and it was awesome...everything was mid 1800s, and shallow. There was areas that where scraped deeper, and these where sterile. I wish we had gb pros or vistas back then...I did the best out of the four of us, I was using a Tesoro, everyone else stuck to their explorers.
Someday I'll dig up the pictures of the Great Oakland dig we had 10 years ago...it will illistrate your point Tom. Ray

Much like tarets get collated when waves hit the beach in the soft sand most items sink to their equal mass. Targets also get covered up by wind movement, rain, trees leave and our moving soil around.

Dew

The earth is alway shaking and stratifiying. You may not feel it very often but it is going on right below your feet.

HH
Mike

Hi, I'm a little skeptical on your statement made in #1....Now here's my reasoning behind it...Okay I worked an old fairgrounds with a Fisher CZ-3D,Minelab,Garrett,Tesoro etc...I pulled well over 100 Indians two years ago not to mention finding Seated coins,Two Cent pieces etc. and not one of them was over 8" deep...Now this placed has been beat to death by people for years and years, heck I even detected it years ago and done really good....Does this mean I can't reach any coins over 8" deep in that soil? Or does the law of physics not apply to you in Florida? I do however, believe that the better finds are usually found at deeper depths..On the other hand I'm a firm believer that a lot of coins are simply covered up with new dirt during landscaping etc.....I also agree that some coins sink beyond the range of detection but certainly not in every single piece of ground especially with a clay bottom or shallow bedrock.This is a very good topic Tom and makes you wonder what we are leaving in the ground? Will technology ever catch up with the sink rate that we all face? I'm going to say "probably not" ....Thanks.... JJ

i believe alot has to do with the type ground you have..

I have hit spot's around here over the years and sometimes the relics are in the 12-24 strata but the dirt is not of the clay type...

trenchlines are filled in deep and are of a red clay and stuff in them is deep. purposely...

but in the natural area's with 12-14 inches of top soil then a harder denser clay bottom that has never been plowed I have not seen a lot come out of it and I have my buddy's front end loader to make the work easy and at a point below the plow lines in hard ground the finds stop...no nail's or nothing..even going down 3-4 feet and all the finds are confined to the top 14-15 inches in saturated house sites even...

take a house site and systematically scrape it off with a front end loader and eventually finds play out ..talk about some dead dirt...If the house sits is natural mind you...never flipped or anything...

Other places once you hit the natural untouched hardpan (I call it) the find's die out also...

The more loamy the soil the deeper the sinkage...unless theres a more solid bottom then it comes to a halt...now fill in sites are different I have seen relics 4- 5 foot deep in those area's around here...

for years I have excavated sites and they all are different...down on the coast of South Carolina you can keep on keeping on and the relics dont play out...

Back in the 90's during the building boom I saw 3 ringers down there on island's in archaeological test pits at 5 feet....

Yes things can get quite deep if you know which ground's to read for the deeper layer's to come...

Keith

I would love to rip up the blacktop in my town.

Detroit was founded in 1701. Just sayin'.

Yes I agree Keith, and that's exactly what I was thinking regarding clay. In a 200 yr old area I've been hunting for going on 27yrs now, the clay is very close to the surface. I've found Barber quarters, and all other coins as far back as 1853 between 1-5" deep. Once things hit clay I believe it's very difficult to sink unless there is top soil or natural decomposition.

Nice post Tom.

It certainly holds true in New England, or at least western MA where I am at. I was eyeballing a house from the late 1800's that was being demolished for a CVS. Before I could detect it, someone else did. I still detected it, but only got a couple of Indians and wheats for my trouble. It was on a corner of the Boston Post Road, a very old road leading to Boston in the 1700's. Finally they demolished the home and scraped most of the top soil up. From what I could tell, most of the yard had around 11 or 12" removed. I had a limited window to detect, since once they start building, they are quick. So I stopped to detect it. I was using a White's DFX at the time. Very quiet with just some iron targets. Then a shallow 1" deep target reading quarter. Out pops a 1790's 2 reales. With the rest of the soil, that makes a 12-13" target. 2 more Draped Bust large cents came out at similar depths. I don't know what was on that corned prior to that late 1800's house, but it held 3 early coins at deeper than usual depths.

Some really nice finds for your efforts.
Congrats!

Locally a few yeras back, they tore up some ground to make way for a new WalGreens. It was right beside a Civil War era house still standing. They took the dirt down a good ways...I don't know how deep city water lines were put in to, but they had scraped off the soil down to the old city water pipes, as they were in pieces on top of the ground that they had taken it down to. I imagine it was a good 2-3 feet that they went down to. I got to hunt it for about 30 minutes before they begin to back fill it. I found a few coins..oldest was an indian head cent from the 1880s that was just a couple inches deep. This was in ground that was nothing but red clay.

I also hunted another site that was in around Marietta, GA that was also going to be some kind of pharmacy place. There were other relics hunters at it, and the workers had just knocked off several feet of top soil. Yet they had found a couple artillery shells at the site that were another 2+ feet down. This was kind of a yellowish/orange looking clay with little white rocks in it.

Keith Southern Wrote:
-------------------------------------------------------
> i believe alot has to do with the type ground
> you have..
>
> I have hit spot's around here over the years and
> sometimes the relics are in the 12-24 strata but
> the dirt is not of the clay type...
>
> trenchlines are filled in deep and are of a red
> clay and stuff in them is deep. purposely...
>
> but in the natural area's with 12-14 inches of top
> soil then a harder denser clay bottom that has
> never been plowed I have not seen a lot come out
> of it and I have my buddy's front end loader to
> make the work easy and at a point below the plow
> lines in hard ground the finds stop...no nail's or
> nothing..even going down 3-4 feet and all the
> finds are confined to the top 14-15 inches in
> saturated house sites even...
>
> take a house site and systematically scrape it off
> with a front end loader and eventually finds play
> out ..talk about some dead dirt...If the house
> sits is natural mind you...never flipped or
> anything...
>
> Other places once you hit the natural untouched
> hardpan (I call it) the find's die out also...
>
> The more loamy the soil the deeper the
> sinkage...unless theres a more solid bottom then
> it comes to a halt...now fill in sites are
> different I have seen relics 4- 5 foot deep in
> those area's around here...
>
> for years I have excavated sites and they all are
> different...down on the coast of South Carolina
> you can keep on keeping on and the relics dont
> play out...
>
> Back in the 90's during the building boom I saw 3
> ringers down there on island's in archaeological
> test pits at 5 feet....
>
> Yes things can get quite deep if you know which
> ground's to read for the deeper layer's to
> come...
>
> Keith
------------------------------------------------------------------------------------

Same problem in Michigan here

in some areas the top soil is sandy and in some areas it's black dirt and in some it's black dirt mixed with clay

the hard-pan (clay layer) is anywhere from approx. 1 ft below the top soil to around 5 ft depending on how far north/south or east/west you hunt/dig

here where I live now it's about 2 ft on avg. below the top soil AND the soil is sandy/loamy so coins, relics, etc. sink much deeper/much faster in this area than in many other areas of the state (which Po's me to no end)!

On a similar/related note - there's a 1 square block area black topped over where an old school used to be ( from the 1880s to around 1935) (it's a parking area for semi trailers) and it's going to be torn up (the black top) this spring/summer for a re-do as it's so far gone that they can't just "fix" it anymore so I'm just WAITING for the moment they begin that project as not many people know a school ever sat there (took many many hrs of research and reading various articles & excerpts to find that info as it's not just plastered all over for the masses to find) and so - I'm gonna have a field day in there when they scrape off the black top and a few inches of dirt to ready it for the new black top!



Edited 1 time(s). Last edit at 03/12/2013 02:15AM by MichiganRelicHunter.

Very limited on time right now.......... for just one comment:
Coins are VERY solid/dense............. and dirt (even clay) is exceptionally low density...... as compared to a high density solid metal coin.

The moisture content of some clay's can make a huge difference in how easily stuff will sink in them.I have some nice grey clay on my farm that when quite wet will swallow my D6 Cat but when dry I can hardly scrape an inch at a time with the same bulldozer when working on a lake.

I prospect for gold a lot&I can tell ya clay often stops gold. And gold is heavier/denser than coins/although my gold is usually a lot smaller than coins.

I live in an area where things have layed on or very near the surface for 30 thousand years and more and don't sink.

There is a huge difference between desert and Florida. In dry areas surface depletion is a larger factor than soil accumulation. That is how nugget patches form - the heavies all end up on the surface as the soil depletes. Sink rates like most everything else are site dependent. But no doubtwhat Tom says is true in most places suitable for long term human occupation. Human occupation alone adds to the accumulation of surface debris.

So fire up your GPX 5000 people and just get digging. Depth and masking is not much of an issue if you use a PI and dig it all. The technology exists. The simple fact is people just do not want to dig all the junk and that in most urban areas it is not practical even if you wanted to.

Steve Herschbach
DetectorProspector.com



Edited 1 time(s). Last edit at 03/13/2013 04:03AM by Steve Herschbach.

Like many have said before me it depends on the ground in question.Even in a specific areas some areas silver coins are 5-6 inches in depth while a mile away better have a unit that goes 10 inches plus. Basically hunting one fresh beach popular in 40's all the old coins were 8-9 inches deep and stopped sinking when they hit the hardpan.
Am sure there are other reasons deep or shallow and no specific answer just guesstimates in most cases...and the debate will continue...
PS: fellow hunters are sure lucky when their area produces shallow silver and in other areas guess just buy a longer digger...



Edited 1 time(s). Last edit at 03/12/2013 02:19PM by Dan-Pa..

I was way out in the country at the site of an old church. Late 1800's until mid 1900's. The owner of the adjoining property, a man about 75 yrs old, said that his father went to the church house yard after the church had closed it's doors. He said that his father found coins there. It got my hopes up since I was unloading my gear. I asked...."Wow, what kind of detector did your father use????" (I wasn't even sure if detectors would have been around then...at least for hobbyist). He said: " My daddy didn't need a detector. The coins where all on little towers of earth formed when the rains washed the earth away from around the coins....leaving the coins on little towers of earth!! The weight of the coin kept the dirt under it from being washed away....so he just went along and picked them off the little towers of earth and put them in his pocket." He said that there was some....
"Indian head dimes"... amongst the finds. The man relating the story didn't seem to be a coin enthusiast so I didn't say: "Do you mean 'Indian Head cents?". I just let it ride. After he left to go check on the timber cutters on his land....deeper into the woods. I went directly over to the church. It was 10 minutes from being to dark to hunt. I was 25 miles from home. I hunted a few minutes and found a Wheatie. The ground was thick with old nails. There was an old one room school house about 50 yards behind the church. I hunted it the other day (found the foundation stones and old outhouse holes) and found a child's ring (of brass or copper) and an Alabama Tax token (that seemed better made than the quarter-sized aluminum tokens with a hole in the center). In fact, I thought it was a tarnished half dime. It was well made....for a tax token, and seemed to be made of the same material as a penny. I am going back when I get several free hours to hunt it. It's way out in the backside of nowhere. Very peaceful with a clean branch meandering close by. I'll check the branch out as well. With the AT pro and small coil. Should be fun and peaceful. The man who had come by and talked to me had gone to school in the little one room school house (long since torn down and timbers removed) and showed me the foundation stones and outhouses. He said: " I'd be very surprised if you find any coins at the schoolhouse as all of us were VERY poor and we ALL carried our lunch to school as this was before the nickel lunches." We didn't have a penny to our name. I found an axehead there, and a scoop of some variety, likely to remove ashes from the stove. Found the stove door....broken.
But....the point being....the coins with the dirt washed away from around them was eye opening. Talking to this man, I didn't discern him to be a man who spun tall tales, but rather, a down to earth, hard working, farmer who didn't seem to have the extra time to spend spinning yarns about something like that. I found that very interesting though. By the way, the dirt around there is about 75% gravel and rock. Can't wait to go back and grid it off and hunt it with some organization.

Out West (western part of U.S.)..... in certain areas where there's virtually no dirt...... the ground is like concrete......... Indian Head's and other old coins can be found with barely a dusting covering them (and virtually no oxidation.... as the local climate is extremely dry w/low humidity). In other parts of the world where the ground is a granite/rock structure....... presents another extenuating circumstance....... of a nearly zero sink-rate. I'm sure there are also other circumstances whereby...... targets do not sink....... or where wind will carry away sand/dirt........ and expose targets; however, most land masses are some form of a dirt structure...... thereby, presenting a sink-rate.

Also............ if....... during the Roman Empire............. say 1-Billion coins were lost/discarded.............. and............ for what ever reasoning/justification............. 1% of the coins did not sink deep (beyond a foot)...and were within the 0" - 12" depth strata....... how many coins would that be?..... subsequently allowing detectorists to make the claim that "old coins are shallow".

Kevin B.......... that is a exacting story (phenomenon). It is common to find coins on the wet slope beach .... atop 3/8" high mini castles........ whereby the undertow eroded the sand underneath the coin..... looking like the coins were placed on 3/8" high sand castles...... just slightly less than the diameter of what ever denomination coin incurred underlying erosion. This is especially prevalent after a NorEaster.

Another notional calculation (for perspective sake)...

The United States has 3,537,455 square miles of land mass. That is is 98,618,585,472,000 square feet of land (98.6 Trillion).

Based on mint records and some guesswork, the total number of coins minted by the US mint is about 700,000,000,000 coins (700 billion).

Based on some calculated annual loss rates it would probably run about 1% per year, more or less.

So, perhaps about 7 billion coins of all denomination were lost.

Studies have found that large size coins are lost less often, as were more valuable coins. So, the majority of lost coins are going to be the lower denomination and smaller coppers and not silver or gold larger denominations.

If we took those 7,000,000,000 coins and scattered them about the USA evenly, there would be about one coin in every 14,000 square feet. Obviously not all lost coins are lost on the ground, many are in jars, taken to foreign lands, or are unrecoverable, or just destroyed. So, assume that of those coins lost per year ~20 out of every 100 end up in the dirt (20%).

Thus, of the 7 billion lost outright, we would expect about 1.4 billion to be in the ground in the USA. That's still a lot of coins.

So, now we have 1 coin in the ground in every ~70,000 square feet, or approx. 1 coin per 1.62 acres of land (on average across the country)

Of all the land in the USA, only about 6% is developed and the rest is farmland, mountains, fields, desert, or forest etc. If we assume that 10% of the landmass has had a fairly high occupation rate over its history, then most coins will be within that 10% area of human occupation.

Now, assume that of the 1.4 billion coins lost, that 1.3 billion are within the 10% of current and former occupation centers in the USA. Also, assume that whatever former occupation centers in the colonial period, during expansion, etc., most continued on to be developed into cities and towns over the last 200 years (not reverted to ghost towns).

So, now we have 1 coin in the ground in every 7,586 square feet, or approx. 1 coin per 0.174 acres or 840 sq yards within populated areas in the USA.
That leaves about 1 coin in the ground in every 88,757 square feet, or approx 1 coin per 2.0 acres (9,821 sq yards) in unpopulated areas (the other 90% of the USA).

Therefore, there are about 12x more coins in populated areas. If all coins were detectable in the populated locations (not too deep) and your detector hit on each one, then you should uncover 1 coin in about every 2.5 hours of hunting (at a normal sweep speed). In the unpopulated areas you would expect 1 coin to be found in every 27 hours of hunting.

In the populated areas that 2.5 hours of hunting would more likely produce a smaller copper coin rather than silver/gold coins which were more valuable and/or larger and lost at a lower rate. If 50 low-value coins were lost for every larger silver coin of higher denomination, then expect to hunt for 125 hours before uncovering a silver coin of higher denomination.

If you hunt 5 hours per day, expect 25 hunts before you find your first silver. If you hunt 4x per month, then you should find 1 silver coin of larger denomination every 6 months or so, in areas considered populated. In the unpopulated areas in America, you would hunt for about 1400 hours to get that first silver, or 270 5-hr hunts. It would take almost 6 years of hunting 4x per month before you got your first silver.

Happy hunting

If coins or other objects sink because of thier weight, why do pull tabs sink? they have approx. the same S.P. as sand. It would be intresting to place a coin or other object on DRY beach sand and cover it with a large box to protect it from wind, rain and feet and note how long it would take to sink. I suspect it would be a very slow process.