Written by the TreasureGuide for the exclusive use of the Treasure Beaches Report.
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Finds from the North. Source: See ack.net link below. |
Reales are found in places other than the Treasure Coast. Here is the link to one such story.
History unearthed: Metal-detector finds rare Spanish silver on south shore | Lifestyle | ack.net
Thanks to Trevor M. for this link.
With the recent storms and King tides in North Carolina, I'm sure they'll be finding some good old shipwreck treasure. Some of the Outer Island roads were closed.
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I forgot to mention that both Walton Rocks and Blind Creek were closed yesterday. The access road at Walton Rocks was terrible, so maybe they were fixing that. Blind Creek is getting a paved lot and other improvements.
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Below are some of the highlights from the current Sedwick Treasure Auction, which is now online.
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I'm going to start a series of posts on how coins move in sand. That has been a popular topic lately, and I want to address it. I've never found it easy because it is so complex, which means it will probably take several posts to cover. I've posted some on the topic in the past, but some of those posts were long ago, and this time I'm going to try to put it in a series rather than different parts of it at different times. I don't know if I'll succeed or not.
I'll start today with some necessary basics.
Here are five ways I've observed that a coin will move on a beach.
1. Fall out of an eroding cliff, cut or dune.
2. Slide down the face of a cliff or dune.
3. Move within a rush of water.
4. Roll down a slope.
5. Flip.
As I've said many times, there are other things beside the density of an object that will determine how it moves on a beach. Shape is an important characteristic.
Detectorists often talk about heavy objects, but it is more about the object's density than weight, although when everything else is the same, weight is a factor. As I said long ago, a ton of Styrofoam is heavy, but it still floats, but there are other important factors besides density. Shape is an important factor. Roundish things are more easily moved than flat disks, for example. You can see that simple demonstration by using this link. The Treasure Beaches Report Direct From Florida's Treasure Coast.: 8/5/13 Report - What Actually Determines How Obects Move On a Beach Or In the Water.
To sum that up, density, shape, and even weight (to a smaller extent) will determine how various objects will be moved on a beach. Coins, being relatively flat, do not present much surface area to the force of the water. You might say it is aerodynamic, although we are dealing with fluids.
Before being moved (or transported) by flowing water, objects must first be suspended. If a coin or other object is lying on the sand and the water flows over it, the flow will move more easily moved materials around it (such as sand).
Sand takes relatively little force to be moved. Pebbles, rocks and objects like coins, generally require more force to move them. When there is a small amount of flow, or force, sand will be moved but coins will not. If there is sufficient force, both sand and coins will be moved, but the sand will move more, or farther, than the coins.
Objects will be suspended before they are transported by the flow. Some objects require more force to suspend than others. An interesting illustration is clay, which is not as easily suspended as grains of sand. Sand, of course, is suspended more easily and quickly than things like coins.
The force of water flowing on a beach constantly varies. When it gains enough force, objects will be moved, and when the force diminishes, objects will settle. This is one way it gets very complex.
When the flow of water is sufficient to move both sand and coins, both will move, but the sand will move farther. Coins and rings will generally lag behind the sand.
I used to say, "Follow the sand, but don't catch it." When sand moves it goes somewhere. It leaves one place and ends up someplace else. It goes somewhere. People may not think about that. Coins and things can lag behind the sand to some extent.
To give an example, imagine a sand bar a little way out from the beach. If there are coins on that bar, maybe buried a few inches, a moderate to small surf will can move from the back of the bar to the other side. And it can fill in the dip between the bar and the beach.
During summer conditions when you have small waves, sand will often build up on the beach. Not only is it washed up, it is dropped there. There is a change in the flow that makes that happen.
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Clip from a Video of a Wave Tank Showing a Beach Profile. |
Wave tanks are unrealistic in many important ways, but they also illustrate some basic principles. The dotted line shows the starting profile of the beach before the waves were started. You can see the beach profile after some time of wave action. You can see a small cut at the top of the beach, and you can see where the sand piled up at the bottom of the beach under the water level.
That is a pretty good picture of what happened on the beach I showed on the Fort Pierce beach cam of the area south of the Fort Pierce jetty. I think it was 8/29 or thereabouts. A very similar small cut occurred at the top of the beach. A day or two later, the cut got washed out and a day or two later a larger cut formed a little lower on the beach. In both cases the sand removed from area in front of the cut was pulled down the slope. That continued for days. A day or two ago, I showed how the beach at Frederick Douglass was made smaller and the sand bar that was created in front of the beach. The sand bar was exposed at low tide, which is when I took the photo.
Wave tanks fairly show fairly accurately what happens to real beaches when the waves hit the beach straight on, but wave tanks never show a beach being hit by waves coming at angle. The situation with real beaches are usually more complex. The beaches do not run in a straight line. The shoreline is curved or crooked and the curves cause waves to be reflected. There are also reefs and other things that will affect the flow. And wave tanks almost always show a wall at the back of the beach, which is something like a beach that has a large cut dune at the top.
I need to stop there for today.
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Source: SurfGuru.com. |
Looks like we'll get another little increase in surf in a day or two.
The King tides remain high.
Good hunting,
Treasureguide@comcast.net