Written by the TreasureGuide for the exclusive use of treasurebeachesreport.blogspot.com.
I found another very good photo breaking down a typical beach. Beach detectorists typically only detect a very small part of that. We detect from the dune own into the water a short distance, but what diminishes the area covered even more is the fact that we only detect a few inches of the surface. That would be the top few inches along the area shown in red below. That isn't much of the beach.
First we have to narrow down the area of the beach where we want to detect, whether it is the dry beach, wet sand, shallow water, or what. No one actually covers the area all the way from the dunes down and into the water. That is simply too much area to cover. You usually would be prepared for one area or another. If you are working the dry sand you might want one detector or if you are working the shallow water another detector. Maybe a different scoop and other equipment as well.
But my main point here is that you are only detecting a few inches of the surface of part of the beach. Even with a very good detector you aren't getting into the deeper layers where there might or not be good things to be found.
When beach hunters are successful, the treasures are on or very near the surface for one reason or another. Either they have just been deposited there (washed up or washed out) or a deeper treasure bearing layer has been cut into by mother nature.
When things are deeper into the yellow or one of the other layers shown above, we're not going to get them.
There is one way that the top diagram is not like what we have on the Treasure Coast. The diagram shows various layers including sand, peat and clay, and we saw in a recent post a picture of a beach where those layers were being exposed, but the diagram does not show rocks.
You can see the rocks in many places along the Treasure Coast - a lot along South Hutchinson Island.
You can see the rocks, actually reef, at Walton Rocks and down around Bathtub Beach, to name two notable locations.
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| Exposed Rocks On Treasure Coast. |
At some locations the rocks are covered by a lot of sand and at other locations the rocks are actually exposed, at some times more than others as the sand comes and goes. The big advantage the treasure boats have is that they can remove the sand with blowers, and that is how they have been finding old treasures such as those that I've reported in the past. The finds that I've reported were made after sand was blown away to expose coins and things that were laying on the rocks in pot holes and cracks between rocks.
Beach detectorists, on the other hand, are almost always detecting through inches or feet of sand. We are dependent mostly upon Mother Nature depositing or exposing coins so we can find them in that few inches of surface that we have access to. Old things also are occasionally made accessible when man moves sand, such as during construction or beach renourishment or something like that.
Rocks can provide a good indicator of the movement of sand as the rocks get covered or uncovered.
There is at least one Treasure Coast beach where I suspect that the reef covers a wreck or parts of a wreck.
I wanted to talk about the rocks today because that is one thing that the diagram left out, and they are very important.
Once in a while you will even find an old coin or something in a rock-like conglomerate. That is not uncommon. Very often it will be iron.
I've seen what looks and feels like sandstone form in about a year. That sounds impossible, but I've seen it. It doesn't take very long for a sand and things to solidify in some places. If you walk along the West bank of the Indian River and look at the lower concrete blocks that they put there to prevent erosion, in some places you'll see where sand has formed sandstone on the concrete blocks.
What you'll mostly see along the Treasure Coast beaches is a sharp type of rock like that shown in the picture above, but a few feet under the front of the beach you'll see large smoothed out flowing rock too. You'll see the same or a similar kind also in places along the west side of the Indian River in places.
The coins found in deep pot holes won't be washing up in the near future as the result of nature. It will take one heck of a storm to move most of them. Others are more vulnerable.
What we're normally waiting for is a cut, something like that shown by my orange line above, where sand is removed and older layers are exposed. That line is a little deceptive though. You won't have a cut in one place without sand and things being moved elsewhere. It is all connected.
The cut might cut into a treasure bearing layer, or coins might be deposited in front of the cut. It could work either way. And we've also in the past talked about other possibilities such as when coins are thrown up on the top edge of the cut.
In any case, don't forget the rocks. They provide a surface beyond which things will not sink. Sometimes that is close to the surface and sometimes it is several feet under the sand.
Along the west bank of the Indian River I'm told by the guys who place pilings for piers that the hard bottom is down about six feet. Along the beach the rocks are sometimes exposed, such as on South Hutchinson Island, but up north, typically more like four feet- give or take.
As a detectorist, I've there have been a very few occasions I've seen when feet of sand has exposed treasure bearing rock. When that happens you can find heavy concentrations of modern and/or older items.
I think I'll end there today.
Here is the link where I got the top diagram.
http://geologycafe.com/erosion/coastal.html
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There is no significant change Treasure Coast beach detecting conditions. More of the same.
Happy hunting,
TreasureGuide@comcast.net
