Interesting Hunt Conditions And Another Lesson Learned

[GB_Amateur]

Unfortunately this story isn't about an interesting find.  I haven't had many of those this summer but autumn weather (cool temps, cloudy skies, and many fewer park visitors!) are opening up so maybe I can break the bad streak there.

I was in my favorite park where I've been searching most of this pandemic year.  I've saved some of the parts which are most frequented by park visitors and thus the most difficult to exercise social distancing.  (Most wear masks, but not all, and I don't like to detect with a mask on so I just do my best to stay far away from people, which works.)

There is a ~2 meter wide walking trail about 120 meters long which is hilly and wooded on one side with a shallow creek on the other.  The trailhead is in an open area which I've hunted more than once this year with modest success (old coin wise).  As I got a few meters from the trailhead (detector running) I started to pick up quite a few ferrous hits -- considerably more than typical for this site.  I quickly decided there may have been a building or fence closeby in the past.  But as I started up the trail it continued.  I'm talking 6-10 ferrous hits per swing.  And it's pretty consistent.  I checked my ground balance and it was fine.  The hits were peaking in the -4 to -2 range, so very unlikely to be hot rocks (which are rare around here, anyway).  I walked into the wooded part next to the trail and the ferrous hit rate dropped.  I was using the ML Equinox w/11 inch round DD, Park 1, 5 custom tones, gain = 23, recovery speed = 4, Iron Bias F2 = 0, no discrimination/notching.  As I've been doing lately, my user profile was Park 2, 50 tones, recovery speed = 6, IB F2=0.  I use that for target investigation.

I continued up the trail, only having to step aside for one small group of 4 people.  On the way up I was covering the full trail with my overlapping swings and on the way back I went more quickly but still covered maybe 50%.  During the ~2 hours time I found two 22 casings (surely over 50 years old since this is a municipal park) and one green (95% copper) Memorial(!) cent.  Date turned out to be 1967.  It was as green as most of my oldest Lincoln cents and the typical Indian Head cent finds in my area.  I also dug a couple beavertails, but only 2-3.  Normally I'd get about 10 or more at this site over that time period.  None of these recoveries was deep; the Memorial was deepest -- maybe 3 inches -- and it was not a clean signal (nor pure VDI) at all.  In that particularly recovery I got two pieces of wire and a boot tack(!).  (Gold detectorists, you know the feeling. 😁)  Another hit that sounded decent (far from ideal) turned out to be a small nail.  So what was up?

Here are some more clues.  The trail itself was gravel paved, with the size ~1 inch and larger.  But unlike most of the trails in this area, it was water rounded gravel, not sharp crushed limestone or tiny river gravel.  That was another headscratcher.  Also, this park was a Work Progress Administration site (1930's federal government employment program to improve infrastructure and provide jobs) with many signs of that still remaining.  After getting home and contemplating all this, I think I figured out what was up.  (I'll let you speculate if you're still following this post and have interest in trying your sleuthing skills.)

The lesson I learned (again, only after getting home) was that I should have adjusted my detector and settings.  Would the 6 inch coil make more sense?  What about a faster recovery speed?  And now reading ElNino77's comments on discrimination, how about silencing the low (ferrous) VDI bins?  (BTW, I did check what the Beach modes sounded like -- just as bad.)

This trail has been used over 80 years (WPA ended about then).  Maybe there are detectors better suited (e.g. XP Deus/ORX) but even they won't make this area a cake-walk.  That means there are likely some juicy old coins here as any previous detectorists would have had similar problems.  Any other suggestions on change of settings or detector are welcome.

[kac]

Did you check the creek banks at all? Lot of iron it could have had a fence at one time and not necessarily a building. Did you dig any of the nails to get an idea of their age?  Any signs of dirt being pushed to the sides to make the trail?

Usually if there is a lot of iron depending on which machine I just run the iron audio really low, enough that I know there is iron there and listen for the spikes and investigate them. If the targets are real tight then the 6" coil might help as it is shorter and less likely to mask on paralell targets.

[Joe D.]

GB,

   Having read your posts and responses for awhile now, i don't think i have much to offer you! Your way ahead of me in detecting, knowledge wise! But i will humbly offer my two cents!

    Digging several more of the ferrous targets at a few different areas of the trail may give you a general consensus of the source! It sort of sounds like the gravel was mixed with, or laid over, some consistent source of ferrous material! Maybe natural; but most likely man made! Possibly shredded tires, shredded pallets, crushed recycled concrete, or some type of underlayment used to hold the gravel in place! Or was replaced by the gravel!?👍👍

[EL NINO77]

GB .... the answer of your terrain in the range -4ID, -2D suggests that the terrain is polluted with iron waste ,, iron mineralization would really give higher iron -8-9 ID ..

since you are looking for an 11 "coil on the equinox ... so I would recommend you to try to increase the recovery in the program Park2 n recovery speed to 7-8,, and the disk to -1ID ... and to check the signal I would put the program Beach 2 in the user program also on recovery 7-8 and setting iron bias F2 to the value 6-7 which will help you in the control comparison of some signals ....

recovery speed 6 is not the final possibility of separating Equinox and at recovery 7-8 you can still detect really good signals ..

Most good goals should have the same ID on both multifrequency programs ... while enough bad goals are just reflected in the different ID when comparing both programs on one goal ...
He gave

Another option would be to use Equinox at a 1F frequency of 15-40khz to try to cross this terrain like this .. at a higher sensitivity of the detector ..

[GB_Amateur]

I was out in the park today searching nearby so I decided to try some of the ideas & suggestions you guys have provided.  Thanks to kac and Joe D. for those.  ElNino77, I didn't see your post until I got back home.  Thanks and I'll do some experimenting with your recommended settings.

I was detecting with the 6" round DD (excellent coil -- found some coin-ID non-ferrous in areas I thought I had detected and where I'm sure others have, so likely taking advantage of the better separation a small coil provides).  I was playing around with Gold 1 mode, recovery speed = 6, using threshold discrimination set at 10!  (Well, since I don't typically use any disc. that is a lot for me.)  But when I made it to the iron infested path along the creek I switched back to Park 1, no disc., but upped the recovery speed from 4 to 5.  I only spent about 15-20 minutes, my simple goal being to dig some of the iron hits.  I found two small nails (don't know the size, but no larger than 4d) and a piece of barbed wire.  The nails were within an inch or so of the surface and the wire was down about 3 inches.  Hmmm.

I don't think this area was ever fenced, at least not along the path or creek as it is a natural gully, but it's not impossible.  IMO it's more likely that the iron trash was somehow embedded in the path's gravel when that was laid down.  I previously thought they might have strained/sifted/classified the creek gravel for the path but I would expect that would leave wire (think lobster traps...), not nails.  So now I'm thinking the gravel was hauled in and for some reason it was 'contaminated' with nails and fence wire.  Not sure why that would be the case, though.  Remember this was done during the great depression so they were likely in recycle mode whenever possible.  There had been a dance hall and swimming pool (with parking lot) during the Roaring 20's that burned down.  I wonder if they stripped the no longer needed parking lot and the nails were mixed within after the fire....

[GB_Amateur]

Back out today (Wednesday) trying out ElNino77's recommended settings (well, sort of).  I accidentally set up Field 2, not Park 2, but otherwise what he suggested.  (I used Recovery Speed = 7.  Oh, and I was swinging the 6" coil.)  I'll take a picture of my 'finds' in the next couple days and post them.  Summary is that I found lots of spent lead bullets and quite a few spent casings.  Some are 22 calbier but others are larger (I haven't measured yet).  Only dug a few pieces of iron.

I've found a few bullets and casings plus one cartridge in this park previously (including several shotgun shell butts) but nothing close to the quantity I found today.  I'd say roughly half that I found were 12-13-14 TID's (USA nickel sweetspot is 12-13) and I tend to dig all of those (except sometimes signals with 14 -- lots of modern pulltabs hit there).  As mentioned before, this trail has been part of the park since the 1930's.  Were they allowing hunting in the park or were these shot prior to that?  Times have certainly changed so maybe many decades ago they allowed hunting in the park, with warnings or even bans to other visitors during those time windows (hunting season).  Seems odd since there are so many places people can hunt around here.  Why allow it in a municipal park?  But like I said, people thought differently in the past.

I will say one thing.  Recovery speed 7 and recovery speed 5 are very different.  That higher recovery speed allowed me to pick up these non-ferrous targets.  There were so many (I could have dug more if I wanted) that I surely had my coil over some previously but apparently they were masked.  A majority were close to the surface.  (Note: I've hunted with both 11" and 6" before.)  But there's a price to fast recovery speed so I'll only be using it on these iron loaded type sites.

In 3 hours searching I only found one penny (think it's a zinc) on the trail and one Wheat penny just off the trail in some soft ground.  I found no pulltabs today which is also surprising.  (I wasn't digging all in the pulltab zone, but way more than I usually do.  I get tons in the nickel zone normally.)  Maybe this trail has been searched by other detectorists....  No way coins haven't been dropped over 8+ decades.  (My Wheatie find is proof.)  Or they are still hiding behind the mask.  If previous detectorists were here, did they not dig the bullets or just leave them after recovering?  I plan on going out again tomorrow and finish up the trail.  I'll also play in the creek.  I found a large pulltab (Pringles can size) and an old beavertail aluminum can lid in the creek today in only about 10 minutes, but no coins.  Where are the damn coins?

Edit:  I've attached a photo of the finds.  Top are iron, middle are general non-ferrous, bottom are bullets and casings.  The small casings look like 22's (no printing on them that I could find) and the larger are 25-20 WCF which were popular 1890-1920 according to this Wikipedia article.  So maybe they really were deposited prior to the park being designated as official Muni property.  Most of the bullets measure in the range 0.30-0.32 inch (~7.6 mm) diameter which doesn't seem consistent with 25-20, though.

[kac]

Have you tried cherry picking the area at all? Disc out everything except your coppers and silver, then go back and disc out everything except a slim nickel range and maybe keep ring pulls? Will take a few passes but I don't think the park is going anywheres soon.

How deep is that creek? Shallow enough to toss some rubber boots on it might be worth poking around in and even along the banks.

[GB_Amateur]

27 minutes ago, kac said:

Have you tried cherry picking the area at all? Disc out everything except your coppers and silver, then go back and disc out everything except a slim nickel range and maybe keep ring pulls? Will take a few passes but I don't think the park is going anywheres soon.

How deep is that creek? Shallow enough to toss some rubber boots on it might be worth poking around in and even along the banks.

With the settings (from ElNino77) it's pretty quiet so I don't think increasing the discriminator threshold will bring out more targets.  I'm using my custom 5 tones (although one of those is for subzero ferrous and thus wasted when discing).  My ear is well trained for that.  I mentioned there are more bullets but even those aren't so plentiful as to cause problems.  The real problem is the iron masking which thanks to ElNino77 I'm doing better handling, but there is a limit to unmasking as most know.  (I'm sure I'm not yet optimally tuned for that.)  BTW, I've added a photo to the original post plus a bit of explantion.

Yes, the creek is shallow and easily searchable with knee-high rubber boots.  I'm going to do some more test searching today but no way I can cover it in one day (3-4 hour) hunt.  If I find any old coin you know I'll be back again!

[Johnny Crunch]

Enjoying this investigation thread immensely! Particularly amused with the mental image I have of a bunch of prohibition drunks discharging weapons at the dance hall parking lot; then the WPA re-uses the contaminated gravel on the creek trail! But seriously I'm closely following the various settings adjustments, and your result reports, as someday soon I hope to afford a Nox 800... I agree: 'Where are the damn coins?'

[kac]

Sometimes in high trash areas I will take my Tejon and just buz through listening only for a small range and basically wead out the easy targets first. the last I start listening for the masked objects such as broken iron signals and targets that are only heard in one direction or on one of my other machines will use all metal mode and pick through the rest. Technique has been useful for me over different areas with a good degree of success and isn't really machine brand or model specific. I just go brain dead if I have to listen to too many targets and try to id each one especially when there is a half dozen or more on a swing.