Tom, have you counted and calculated the % of nonferrous targets...

Say from 0-6", 6-8", 8-10" and 10"+ in your mild ground.

Just wondering if that been done.

So say an AT Pro can detect to 9" and someone can see what percentage of nonferrous targets it can find in that particular soil.

Calabash was talking about that on a video and I thought you might have done this.

It would be interesting to see what % of nonferrous targets a particular detector could find.

Unfortunately this would have to done in different soil conditions which would be nearly impossible to see each detector % of finds in there soil.

If you have done this in your soil it would be interesting to see your results.



Edited 1 time(s). Last edit at 02/24/2023 11:42PM by Rick, N. MI.

Rick...........this may not answer your question. , . , . , . , . but I have performed 'similar' data collection.....in a scientific fashion......rather than empirical methodology.
This was at a site with heavy human (military) activity from 1849-1858.
It was performed in a Archaeological Phase-1 & Phase-2 site excavation process. . . . . . with intent to determine: era.........VS..........depth stratification layers.
Different sites produced different results; yet, in this case (my logs/data-records that were easiest to access) show a particular site whereby...... 41 pit-digs ensued.
My team wanted to know % of 1849-1858 era implements.....at 'what' specific stratified depths. Nutshell:

0" - 9" = 2%
9" - 14" = 7%
14" - 17" = 19%
17" - 23" = 62%
23" - 27" = 9%
27" - 31" = 1%

These numbers were actually in cm (not: inches)....... but I converted into detectorist terms.
The "span" of the depth-numbers were VERY specifically contrived in accordance with a unique guideline set forth by the Archy community.
The (above) numbers/data include Ferrous & Non-Ferrous & Non-Metallic implements.

It is a HORRIBLE mistake to assume: "Old coins are never any deeper than 6" or 8". (For/by the coin hunters).
Or....... to make the assumption that: Most targets are never more than a few inches deep.
Yes...... if you live in the dessert where it nearly never rains.,.,.,.,.,. you may find 200 year old implements just lying on the surface of the ground.
Another crazy thought is: If I find 100 non-ferrous implements from the 1849-1858 era.....with a metal detector.,.,.,.,.,., and they were dug/found down to depths of 11" (and never any deeper).......you feel like a successful hero; yet, this may only be a few % of all the targets ....from that era! (And you would never know it)! You may ALSO (incorrectly) make the assumption that....... no old targets are deeper than 11". (((When the truth-of-the-matter is: your detector will not detect deeper than 11")))!!!
Most Archaeologists have a notable saying: LIFE BEGINS AT 1-METER DEEP.

I could never begin to tell you how many times I would hunt a (say) 1884 church.......... and find a lot of coins dated in the 1910's & 1920's........ that were dropped in 1950. Where are the coins that were dropped in 1935? How about the coins dropped in 1900? And what about the coins that were dropped in 1885?

NASA-Tom Wrote:
-------------------------------------------------------
>>snip>>
>
> I could never begin to tell you how many times I w
> ould hunt a (say) 1884 church.......... and find a
> lot of coins dated in the 1910's & 1920's........
> that were dropped in 1950. Where are the c
> oins that were dropped in 1935? How about the coin
> s dropped in 1900? And what about the coins that w
> ere dropped in 1885?

Excellent point Tom. Obviously beyond our reach?

Thanks Tom.

NASA-Tom,

This is a topic that has always fascinated me.

I assume your results were in sandy Florida soil, correct?

I can definitely say that I OBVIOUSLY don't know what I don't know, but...I do know that soil type MATTERS, obviously. You drew the "Florida sand versus desert" comparison, two of the extremes where old coins would usually be VERY deep (and beyond detection) versus VERY shallow. And obviously, such variables as sediment deposition over time (bottom of a hill/in a valley) versus erosion (on the side of a hill) change things; fill dirt/excavation changes things, etc. etc. etc.

BUT -- with all that said, I can say that it seems to me that coins really don't "sink" all that far in many soil types. Again -- I may be entirely ignorant, not knowing what I don't know (due to depth limitations of detectors, and no good way to know anything beyond that). BUT, I have had so many experiences where coins are found near the top of the "clay" layer, where the upper soil layer (more organic material/humus-type dirt) transitions to the denser clay, that shows how there is a resistance for coins to sink in certain soils.

I also have noted that sites in the woods (i.e. areas where fill dirt is unlikely to have been a factor, excavation is unlikely to have occurred, etc.) that "period" coins are often found 4 to 6" deep. I can think of a particular church in Pennsylvania, built around 1850, burned in 1900, and was never rebuilt. It was a very small, believed to be "one-room" type church. For a bit of background info, it is in a forest, no trace of the building left. Soil is loose/organic in the very shallow top layer (decayed leaf litter, etc.), with a transition to humus-type dirt down to a few inches, and then a transition to slightly/gradually denser dirt beyond a few inches. The ground is very gently sloping. There's nothing "atypical" at this site with respect to soil type; if anything, it would likely promote MORE sinking than some PA sites, as the shale layer (which prevails in southwestern PA and is often shallow, just below a thin soil layer) is deeper than a foot or so at this site.

With that information in mind, I will note that in this site, I've dug roughly a dozen and a half old, period-dated coins, some as shallow as 4" to 5" deep, none deeper than about 7". In particular, I recall a "pocket spill" that I dug, three coins within about a 3-foot radius...Seated dime, Seated half-dime, and Capped Bust dime. The bust dime was well-worn, as expected, with its 1830 date 20 years prior to the church being built. The other two (1853, if I recall), were in good shape; maybe a few years of circulation? Anyway, I think it's safe to say that this pocket spill was clearly dropped in the mid 1800s, I'd guess not later than Civil War era. Now, obviously, any single, shallow coin COULD be a fluke in any give site (came to rest on a root, rock, etc. that prevented it from becoming deeper). HOWEVER, with a slightly-spread-out pocket spill, it's unlikely that EACH of three coins would have ended up "unusually shallow." So, that should be at least somewhat of a good "test case" for determining "sink rate" so to speak. And in this case, all three were roughly 5" deep, give or take an inch. So, in roughly 150 to 160 years, these coins came to rest at only about 5" deep. I don't think I've ever dug a coin deeper than 7" or so at this site, so that's another data point suggesting that there is a limit there as to how deep coins end up...as otherwise I should have had at least a coin or two in the 8"/9" or even 10" depth (as I did dig a couple of large cents here, which would be detectable at 10" with an EQX).

Anyway, just posting some thoughts regarding this matter, as "sink rate" is not something I'm totally sold on, especially in areas where dense soil, with at least some clay content, prevails (which is the case in both PA and OK, where I hunt the most).

Steve

NASA-Tom Wrote:
-------------------------------------------------------
> Rick...........this may not answer your question.
> , . , . , . , . but I have performed 'similar' dat
> a collection.....in a scientific fashion......rath
> er than empirical methodology.
> This was at a site with heavy human (military) act
> ivity from 1849-1858.
> It was performed in a Archaeological Phase-1 & Pha
> se-2 site excavation process. . . . . . with inten
> t to determine: era.........VS..........depth stra
> tification layers.
> Different sites produced different results; yet, i
> n this case (my logs/data-records that were easies
> t to access) show a particular site whereby......
> 41 pit-digs ensued.
> My team wanted to know % of 1849-1858 era implemen
> ts.....at 'what' specific stratified depths. Nutsh
> ell:
>
> 0" - 9" = 2%
> 9" - 14" = 7%
> 14" - 17" = 19%
> 17" - 23" = 62%
> 23" - 27" = 9%
> 27" - 31" = 1%
>
> These numbers were actually in cm (not: inches)...
> .... but I converted into detectorist terms.
> The "span" of the depth-numbers were VERY specific
> ally contrived in accordance with a unique guideli
> ne set forth by the Archy community.
> The (above) numbers/data include Ferrous & Non-Fer
> rous & Non-Metallic implements.
>
> It is a HORRIBLE mistake to assume: "Old coins ar
> e never any deeper than 6" or 8". (For/by the coin
> hunters).
> Or....... to make the assumption that: Most target
> s are never more than a few inches deep.
> Yes...... if you live in the dessert where it near
> ly never rains.,.,.,.,.,. you may find 200 year ol
> d implements just lying on the surface of the grou
> nd.
> Another crazy thought is: If I find 100 non-ferrou
> s implements from the 1849-1858 era.....with a met
> al detector.,.,.,.,.,., and they were dug/found do
> wn to depths of 11" (and never any deeper).......y
> ou feel like a successful hero; yet, this may only
> be a few % of all the targets ....from that era! (
> And you would never know it)! You may ALSO (incorr
> ectly) make the assumption that....... no old targ
> ets are deeper than 11". (((When the truth-of-the-
> matter is: your detector will not detect deeper th
> an 11")))!!!
> Most Archaeologists have a notable saying: LIFE BE
> GINS AT 1-METER DEEP.
>
> I could never begin to tell you how many times I w
> ould hunt a (say) 1884 church.......... and find a
> lot of coins dated in the 1910's & 1920's........
> that were dropped in 1950. Where are the c
> oins that were dropped in 1935? How about the coin
> s dropped in 1900? And what about the coins that w
> ere dropped in 1885?

Sink Rate Inland, a topic that comes up every couple/few years.

Anything that makes the soil move, . . worms, expansion/contraction, water, roots, earthquakes, man, animals, etc,, plays a role for an object with its gravity pull for it to sink, or in some cases rise or go sideways. Then we have fill from man, fill naturally occurring from dying organics and there is constant atmospheric dust.

For the most part, we don't actually know what took place for a particular coin to be at a certain depth. Some of the above or all. . .We can guess, that's about it.

If a coin drops 1/32" per year average, that is only 1" in 32 years.

In 192 years the coin drops 6".

Back 192 years is 1831.

These figures, just gives one sample picture of the many possibilities of why coins are at the depths they are.

I like to hunt around old homes from the 17 to 1800's. Looking at the cellar windows gives me a clue if fill has been added. How much space is between the sill and the soil. If there is a window well I look at the front door, steps, no steps, look at the stone, is their clues like mortar, indicating there use to be steps. If I don't dig any old coins I guess fill has been added and the old coins are out of reach. So many clues to narrow down the ground history of an old property and we still may never know.

There is more to this hobby than you ever dreamed of when first getting started and we never stop learning . .who da thunk it.



Edited 1 time(s). Last edit at 02/26/2023 01:10PM by ozzie.

Steve G........ yes; that's correct. My data is here in this sandbar State of Florida.

In fact........ at my previous house.,.,.,.,., I monitored my test-garden's "sink rate"............and was able to reliably/repeatably witness a 1" sink rate per every 4.5 years. And THIS is exactly what (environmentally) forced me to create 'proof-positive' depth targets.,.,.,.,.,.,., which (culminated) turned out to be 1/2" Schedule-40 PVC sticks cut to exacting lengths.......with targets glued (two-part epoxy) to PVC sticks.
At one point ..... I was using wooden dowel rods (before PVC sticks); yet, the carpenter-ants & termites zeroized my intents!

Steve O........ spot-on! RAIN is another major/major contributor.

Rain, big contributor, covered that with "water" on my list.
Wow! 1" sink rate every 4.5 years . .speed of light down there.

This post woke me from my sleep last night with some possible incites as to my detecting experiences so far ... and a few questions...the percentage graph is seemingly very similar to the valleys I hunt around me and would help to explain some of the reasoning for the coin dates I've dug so far. Dates on the coins are not much earlier than, and seem to drop off in, the mid-1800s ... even though the history here starts in the late 1790s, and somewhere in the 14–17-inch depth is the approximant depth limits of the all-metal mode of the T2. There are clay fields on the hills around where the targets have stopped sinking as they hit the top of the clay layer, 5-6 inches down, but these clay fields are found mostly by happenstance and a lot of leg work as the soil composition maps are very vague and any accurate maps of civilization start in the 1850s. I'm not taking these clay fields into consideration, as they are more of an anomaly than the rest of the areas I hunt. There is also the fact that the valleys around are prone to floods at an interval of about 50 years or so, since recorded time. This would make me guess that sink rates are not as constant, as say, 1" in every 4.5 years, but rather, that could be better described as an average? and the sink rate would also be different up on the hills than it is in the valley? etc...

I assume that while performing the digs that produced the graph, you also found articles from a period before 1849? ...and that the ratio of those targets is similarly proportionate, yet beginning a bit deeper? and any more recent drops/targets than those from 1858 also had a similar, yet slightly more condensed ratio? ...and once you had dug the 9-14-inch layer the 62% layer then became apparent by use of a detector? ...also, I'd be curious of any other similar studies. and if those studies are somewhere a layman could read them on the interweb? How did/do you determine the date of droppage? Wouldn't/don't different compositions have different sink rates? ...i.e., gold sinks to the bottom of the pan.

Scott......... these 41 pit-digs were in a field....... quite close to the Peace River......... private property.......... and (almost) did not have any other activity in this fairly vast, open field......after the 3rd Seminole Indian War. There were a few large-caliber rimfire...... and some early centerfire rifle cartridges (and projectiles) dug....... from passerby hunters in the preceding years after the war/encampment.
Interestingly....... .54 & .69 cal lead round-balls (unfired) would always be found/located a few percent deeper than other implements. (((If you rest a round-ball on a flat table...... ONLY a tiny 'point' of the round-ball would be making contact with the table. Food-for-thought.))).
The implements recovered were highly identifiable from our American United States Army (general issue) implements.
I am a Constitutionalist ....... so it always amazes me to recover ONLY coins/currency ......directly from Article-1, Section-10 of the United States Constitution. "Specie".
There were no previous-era implements that came out of the ground........ as all metallic targets ceased to exist..... past 33". This is not uncommon for Florida......... as Florida was a 'Territory'. Florida became a State in 1845. If we were to do a pit-dig in St. Augustine, FL (1565).......... you would indeed find implements that would date all the way back to 1513....... and then maybe into Indian midden territory....... going back 10's of thousands of years.

One of my other big hobbies is native American artifacts. I have several archeology books from the University of Tennessee excavations of the Tennessee and Little Tennessee River sites before TVA flooded them. What was very interesting to me was the more recent Little Tennessee River sites...they were excavated much closer to present day, in the 1970s. The history of the Little Tennessee River people is much newer than the other sites...what I mean is, they didn't settle into the area until the 1500s and several of the artifacts found, were from post contact with European people...so your looking at 1700s Era. From the surface of the soil, down to where they got to "original strata" levels of the floors of villages, huts, etc in some camps, they had to dig over 20 feet deep. They actually brought in heavy equipment to remove the over burden, which was rare for digs. The reason was attributed to the fertile river bottom soil and flooding. That's mind blowing to me. Yet in the same areas, we can walk fields and find projectiles from the archaic and woodland period laying on top of the ground, exposed by general plowing and erosion.

Daniel........ how interesting!
Yes....... it never fails to amaze me when........after a hard rain.......in a farmers field.,.,.,.,.,., you can find Indian arrowheads simply lying on the surface of the ground. BUT....... what makes it yet another notch more interesting is.......you may find several points (arrowheads) that are THOUSANDS of years apart from each other (era-wise)........ that are all laying on the surface of the ground!