Sunday, September 7, 2014

9/7/14 Million Dollar Coin Found by Detectorist. How Objects Sink Very Quickly Into Beach Sand.

Written by the TreasureGuide for the exclusive use of

Very Rare Coin Found by Detectorist.

I hope you enjoyed seeing all of the fantastic Treasure Coast treasure finds sent in by  Captain Jonah.  Things like that are still out there to be found.  If you didn't see them, you'll want to go back to the previous two posts.

The threepenny piece shown here was struck in Boston, Massachusetts back around 1652 and is one of the first coins struck in what would become the US.  The coin was recently found by a detectorist in England.  Nobody knows how it ended up over there.

The coin, expected to be worth nearly 1.5 million US dollars, was dug by a detectorist who did not know how rare and valuable it could be.  He put it in a jar and lost track of it for a bit.

The coin is a real rarity in any condition, but to top it all off, this one is in amazing condition.

Here is the link to the article about that.   I think you'll enjoy reading it.

The detectorist and landowner will split the proceeds.  The coin is not claimed by England because it is a single coin and not a hoard.  

I wish we had something more like their antiquities laws.

One of the things about this story that is very interesting to me and very relevant to any detectorist is that nobody expected such a rare US coin to be found in England.  Things don't always pop up where you expect them.  It is possible to find a rare coin from England or any other country right here on the Treasure Coast.  It doesn't have to be a US coin, or even a Spanish cob.  You just never know!

Many thanks to Peter H. who sent this link.  He is one of our detecting friends from across the big pond. 

My 9/4/14 post, which discussed how objects sink in beach sand, received the most +1s of any of my posts.  I'll continue with that topic today.

A few days ago I showed how moving water would suspend a layer of sand and cause a coin or ring to sink.  How far the item would sink was very much determined by how fast the water moved, and how much sand was suspended and moved by the current. 

As I showed in my simple demonstration, the objects sank down to a stable layer of sand and stopped there.  I didn't see any relationship between the amount of time the water and sand moved and depth other than the very short amount of time that was needed for the objects to reach the stable layer of sand.  After that the object sank no more.

If this was the only way that objects like coins and rings sank into beach sand, it might take numerous periods of rough seas for an object to eventually sink through enough layers of sand to reach bedrock.  That is not the only way that objects sink though.  There is another thing that causes objects to sink more quickly.

You might have read articles about objects sinking into beach sand very quickly.  I've read reports that seem fantastically unbelievable.  I have however observed something that makes objects sink more quickly than the type of currents I talked about a few days ago.

When I circulated water and sand in a cup, it took seconds for the test objects to sink a mere eighth of an inch.  However, when water was forced down on the sand, rather than simply circulated as a current would do, the sand was quickly suspended and the objects sank much faster.

Here are two very short videos showing what I am talking about.  The only difference between the two videos is the amount of water force.  Take a look.

The results were amazing.  In that one second or so when the water was on, the objects sank an inch or more.  The rate of sinking was many times faster than when the water was circulated horizontally as was the case in my previous experiments.

After turning the water off, I stuck my finger into the sand to find where the objects went and found them down an inch or more.  Each time I repeated this experiment, the results were very similar.  The more force, the deeper the objects sank.

It appears that the downward force of water disturbs sand to deeper levels and suspends sand more quickly than horizontally circulating water, and as a result the objects sank more quickly.

How does that apply to a beach?  Waves crash with a similar downward force.  That happens not once, but repeatedly.  Each crashing wave disturbs and suspends sand.

As the tides go in and out the waves will crash at a slightly different place.  That means a wide area will be affected during each tidal cycle. 

If you have ever observed how they build a dock in the river, you might have seen them pump water downward, pushing sand up and out so that the post can be inserted down to bedrock.  This is a very similar effect.  When the sand is being suspended by the forced water, the post is easily pushed in, but once the post is in place it remains very stable in the sand.  (Bedrock in the river is about six feet deep.)

So now I have described two different types of forces that make objects sink in beach sand.  One is the horizontal current that suspends and moves sand, and the other is the vertical force of crashing waves.

When a wave crashes, sand is suspended, then the water rushes in towards shore, carrying sand with it.

I observed this very clearly on a beach recently when the waves were crashing on a sand bar and a flat layer of sand was being washed in towards shore where it was beginning to fill a small dip.  The front edge of the moving sand was very obvious.  (That was the day my camera batteries were dead.)

I posted this picture of that same beach back in my 8/13/14 post, but now I have a much better appreciation of the forces, how the sand is moved and how objects sink.

Notice the red line where the waves were crashing.  The waves look big, but they were less than two feet on that particular day.  Where the waves crashed, sand was kicked up, very much like in the two videos above. 

Any objects under a crashing wave could sink inches, and maybe more. 

Add to that the fact that the sand would only partially settle before being hit again.  Some of the suspended sand would then be pushed towards shore where it would settle. 

After a wave, the water rushing back out is not moving with as much force as the incoming water and is met by more incoming water.

Another thing to point out is that in the situation shown in the illustration the waves are nearly parallel to the beach.  There is no angle to slice away beach sand.

After objects sink deeply, they will likely remain put until they are uncovered again.  If there is a storm and the water rises and the waves crash on the beach or near shore buried objects can be uncovered again.

On the Treasure Coast we still have a small surf.  There is some weather that has very slight chance of developing into a cyclone over North Florida and another disturbance that is still closer to Africa.  It won't get here for several days, if at all.

We'll have a small surf through most of this week.

Happy hunting,