9/21/15 Report - Scan Patterns and Coin Line Identification. Tropical Storm Ida.

Writtten by the TreasureGuide for the exclusive use of treasurebeachesreport.blogspot.com

One Treasure Coast Beach This Morning.

I took a look at a couple beaches this morning.  I was disappointed.  Yesterday it looked like we might get a little improvement, but not much happened.

The beach shown above is very mushy.  You can see the waves breaking right at the base of the beach.  The slope is fairly steep, ever so slightly scalloped and mushy.  Not good detecting conditions.

Another Beach At Low Tide Yesterday.

Notice the twenty or thirty yards of flat beach out front.  Water from the breaking waves is surging in over that flat part of the beach.

I saw another beach this morning that was very much like this one.

There were few targets where I did a little detecting this morning.  There were some though, although it took me a while to find them.

I started off by checking the two hot spots that usually produce good targets on that beach.  There was nothing at those two spots.  My guess is that the regulars hit those spots this weekend.

I quickly shifted to a very loose scan pattern to see if I could find some better spots to hunt.  I would often use a zig-zag pattern in a situation like that.  Today I checked down by the waterline first.  Nothing good there.  Then I checked higher on the beach.  Nothing there either.

It didn't look like it was worth spending much time either high or low, so then I checked the middle of the slope.  Bingo.  First a dime.  Then a quarter, etc.

There was a coin line.  It was a very narrow straight coin line.  If you looked back and connected the holes with a line, it would have been surprisingly straight.  By the way, this line was not by the most busy parts of the beach.  It was well north of that.  Again, I suspect that the weekenders cleaned the more busy areas.

It took me a while to find the first good target, but after that they came fairly quickly.  I used the first coin as a sign of a possible distribution pattern.  In this case it turned out to be a coin line.

I used the first find as a possible indicator of the most productive zone - in this case not high, or low.

The second find supported the idea that there could be a coin line and that the most productive area would be just a little below, mid way between the water and the high tide mark.

The third find and additional finds were all in that narrow coin line.

I've often talked about using finds as indicators.  Some will not be a part of a distribution pattern, but after finding one, the next thing I do is check to see if it might be a part of a pattern.

All the coins found in that line were discolored.  That is important.  A coin that was just dropped would not be a sign of a distribution pattern.  Discolored coins that have been out there for a while are more likely to be relevant signs.  That is especially true in areas where most coins are removed before long.  A discolored coin that pops up in a heavily detected area probably came from somewhere - either washed up or washed out.

I'm always looking for something to tell me where to spend my time.  First by looking at the beach and any features, considering hot spots that have been found in the past, and then by sampling.

At this point I could get into the details of how coin lines form, but that would take me a lot more time.  I think I'll wind this topic up for now.  Maybe I'll get into how such lines form some other time.
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Here is the auction catalog for Sothebys Oct. 1 Rarities Auction.  There are over 200 lots of very fine coins to browse.

http://www.sothebys.com/pdf/2015/N09385/index.html

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Here is a very good paper on bioturbation and artifact movement.  It shows how significant bioturbation can be.

http://alliance.la.asu.edu/rockart/scans/Balek.pdf

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There wasn't much wind this morning.  I was disappointed that we didn't get more sand moved last night.

Wednesday and Thursday the surf will be up to around four feet if the predictions are correct.

Ida is supposed to become a hurricane in a few days.  It looks like she'll stay out in the Atlantic though.  It doesn't look like she'll affect us.

Happy hunting,
TreasureGuide@comcast.net

9/20/15 Report - 18th Century Merchant Shipwreck Discovered. Processes That Cause Coins and Things To Sink. Bigger Surf Coming.

Written by the TreasureGuide for the exclusive use of treasurebeachesreport.blogspot.com.

Recovered Wood From 18th Century Shipwreck.
Source: see link below. 

The newly discovered remains were found in the Nanticoke River during a bridge repair.  About 20% of the ship was recovered.

“At least three curious or strange carvings have been found,” she said. “We don’t know what they mean. Usually when you see carvings on a ship, they were put there during the construction process, usually Roman numbers, but these were different. There are two geometric patterns (carvings) that no one in our team of underwater archaeologists and maritime historians, had ever seen before.”

Were they simply construction diagrams used when building the boat?

You can see the carvings in the photo.  It is hard to tell if they are anything more than doodles, but that is the kind of puzzle that makes it interesting.  You never know what the significance might be, and as I tried to show with the black light posts, the significance can be discovered over time.

Here is the link to the article.

http://www.dorchesterbanner.com/dorchester/secrets-and-mysteries-buried-in-vienna-shipwreck/

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How do coins sink?  That is a question that was addressed in one very popular post back some time ago.  There was a lot of input from readers of this blog, and I thought it was both interesting and helpful.

I have long maintained that things do not sink simply as a result of gravity.  Gravity is a part of it, but without something else going on, gravity is simply not sufficient to draw objects down through layers of soil or sand.  

Yesterday I became convinced that one process that I did not appreciate enough is what the archaeologists call bioturbation.

Pedoturbation refers to many different processes that can result in the displacement, movement, and burial of artifacts.  Bioturbation, which includes faunalturbation and floralturbation, is the common processes that affect most sites.

The illustration immediately  below provides a very good list of processes that move soil or sand and result in artifacts being buried or moved.

The illustration is found in chapter 11 of Advances in Archaeological Method and Theory edited by Michael B. Schiffer.   Part of that book can be read online. 

Click on the title of the book if you want to read more of that.

Chapter 11 of the book extensively covers site disturbance processes including the effect of animals, including ants, worms, and almost anything that burrows or moves earth.  The effect of these animals is estimated and measured in some cases, and it seems the effect can be very significant, especially when counted over decades or centuries.  Although I had recognized and mentioned the effect of animals in burying and uncovering artifacts, I am now convinced the effect is significantly greater than I previously recognized.

In my previous post, one factor that I felt was one of the larger factors was the creation of top soil by fallen leaves etc.  In a woods where leaves fall and deteriorate, it should be noted that there would be a lot of earth worms there as well as other animals foraging, digging and scratching around.  I am certain that I didn't appreciate the full extent of that until yesterday.

Anyhow, I found the illustration helpful.  It made me also think of underwater environments.  There are plenty of animals that disturb the bottom in the water too.  That deserves more attention.  That could be a significant factor in tight spaces like crevices and cracks.  I'll have to dig into that more myself.

Here is a link to an abstract for a paper that considers the relative effect of sedimentation versus pedoturbation.  I'd like to get that article.

http://link.springer.com/chapter/10.1007%2F978-1-4615-1183-0_10#page-1

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The weather has changed and the wind has been coming more from the east/northeast all day.  The surf on the Treasure Coast is up a little today too.

I visited a couple of beaches this morning and the waves were a little bigger than expected.  Definitely three feet when I was there.

The waves were crashing out some twenty yards on the front of the flat beaches, while on the steeper beaches, the waves were crashing almost right at the waterline.

Wednesday or Thursday we might get as much as a four of five foot surf.

The change of wind direction alone has resulting in some small changes.  Sand has been moving a bit.  I saw a few small cuts - all less than a foot though.

I think some more sand might be moved around a little through the first part of this week, but not nearly enough to change my beach detecting conditions rating.

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Congratulations to Mr. and Ms Dan B.  A nine pound baby boy just joined their family.

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Happy hunting,
TreasureGuide@comcast.net

9/19/15 Report - Surprising Results of Detector Test With Three Small Cobs. Tropical Storm Ida And Other Weather.

Written by the TreasureGuide for the exclusive use of treasurebeachesreport.blogspot.com.

Three Small Under Weight Cobs.

In the past I've talked a good bit about specific target training and tuning.  By that I mean learning the optimal detector settings for finding particular targets, and also tuning in the field for those specific targets.

If you are interested in finding small silver items like those shown above, you need to experiment with different detector settings to find the settings that are best.

These particular cobs are way under weight.  They were found on a beach near a 1715 wreck site. They lost much of the original material.  The one on the left is only about .015 ounces, and the other two around .02 ounces.  The second is actually a touch lighter than the third.  My scale isn't highly accurate for small weights like that.

When selecting test targets, I will often select those that are on the smaller side, assuming that if I can find the smaller ones I will have no trouble with the larger ones.

Size is much like depth in relation to signal strength.  Small items sound much, not exactly, like larger but deeper targets.

One thing I try to keep the same is the material.  If you want to find silver, test with silver.  You generally want test targets that are as similar to the desired targets as possible.  One possible exception, as I said, is size.  Again, I tend towards smaller test targets.

If you are going to hunt for a particular type of item, you want to know if your detector will detect it and what settings are required.  It is best to test your detector before going on a hunt so you have confidence that your detector will detect whatever you are hunting.  What a waste it is to spend hours hunting with a detector set up in a way that would not detect what you want to find if you were right on top of it.

I hadn't tested one my newest detector on small cobs and wanted to find out how it would do with those types of targets, and secondly, what settings would be best.  I had tested these test targets with a couple other detectors, and knew how they would perform, but I wanted to know how this detector would perform with the same test targets.

I took these items out to a space that I have cleaned out and often use as a test area.  I kept changing the settings and modes to see which worked best on these test targets.

My test area is not the easiest even though there is no ground mineralization.  There is a lot of ambient electrical interference to deal with that causes a lot of detector noise.  In this area, there are some inexpensive detectors that actually do better than some of the more expensive and powerful detectors because of the electrical interference.

Which of the above three test targets do you think gave the strongest signal?  You might well guess the first, which is both lightest and presents the smallest surface area.

Charles Garrett in his book Successful Coin Shooting, said that generally detectors are surface area detectors, and that mass makes little difference.  He suggested a way to prove that for yourself.  Take a coin and run your coil over it.  Then take a stack of the same coins and run your detector over it.  You should get about the same signal because the surface area that is presented to the coil is the same.

He threw that word "generally" in there, and that is a good thing, because I have found exceptions.  I haven't done a real precise experiment on that, but I have observed enough to feel confident about that.  There are times when thickness, or mass, seems to make a difference, though not a large one.

To answer the question, the first and third targets (as shown in the photo above) cause much stronger detector signals that the second one.  That is very consistent.  And it proves out with different detectors.

The first item, has a small surface area.  You can see that.  The photo accurately shows that.  It is however thicker than both the second and third items.

The second and third items are nearly the same weight, and one might be a bit thinner than the other, but it is not enough to be obvious from look or feel.

So what is it about the second item that produces a weaker signal?   I can't say for sure, but it does seem to be something other than surface area.  Perhaps it is the material, although the three cobs should not be very different.  They should have similar silver content.  Maybe they are a touch different though.

I've shown in the past that shape makes a big difference.  Detect a coin laying flat, and then turn it on edge and you'll probably notice a big difference in the signal.  On some detectors the difference will be greater than on others.

The second item does not appear to be shaped hugely different from the third item, but it is a little less round.  The first item is much less round than the second, but still produces a better signal even though it also presents a smaller surface area.

I've done experiments that show that angles and irregular surfaces make a difference.  A slanted surface may not produce a signal that is as strong as if the surface was flat and parallel to the surface of the coil.

The top surface of the small item is a little convex.  I don't know if that produces a better signal.

It is pretty complex.  I'd have to do a lot more experimenting before I could say exactly why the second items produces a much weaker signal than the other two.  At this point I just have some ideas.

The main thing I want to say today is that you should experiment with detectors and their various settings and relevant test targets before you go for a hunt.  Get to know what your detector will and will not do, and get to know the best settings.

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Source; nhc.noaa.gov

We now have a named tropical storm, Ida.  Also a tropical depression, Nine.  And another disturbance up by Georgia.

I doubt we get much of anything from any of these, however there is a chance.  Both tropical depression nine and Ida will probably live and die out there in the Atlantic.

The disturbance up by Georgia might turn into something, but North Carolina has a better chance of getting something out of it than we do.

Right now the surf predications are for a slightly increase surf for mid week.  If you look out a week from Monday, they are predicting something like 4 - 7 feet.  That might be nice - if it actually happens.  I guess there is some chance, but I'm not betting on it.

Happy hunting,
TreasureGuide@comcast.net