9/23/26 Report - Bigger Surf Expected to Begin Thursday. Sedimentation Rates and Stratification of Old Items. Florida Museum Study.

 

Written by the TreasureGuide for the exclusive use of the Treasure Beaches Report.

Wind Map from Windyty.com Wednesday Morning.

Above you can see the weather that will be bringing our increased surf in a couple days.  Not the circulation centering to the north of us.  As of Wednesday morning, you can see that the north winds haven't reached us yet.  At the time of the snipping shown above, the wind just offshore of us is going back out to sea and offshore.  When this circulation moves farther south, the north winds will be hitting us, and that is when our surf will be increasing.

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It is generally believed that if a target is deep, it is old.  I hear that said all the time, and it is true at times, but not always.  There are many exceptions - too many for me to take the generalization very seriously.  People easily throw around over-simplifications like that.  

On the beach, you'll find very old things laying on the surface.  There are various ways that can happen.  An old item can wash out of the dunes, or it can wash up, or the surface layers of cover can be eroded away exposing things that have been buried a long time.  

I've pointed out several times how you can often see the some of the layers as you dig into a beach.  The color of sand might change, or you might see a layers of sand and shells.  You'll find layers of shells containing aluminum and things like that down a good distance.  That material got deposited and then other material was deposited on top of it.

 But the layers on land sites are often out of chronological order too.  

That isn't animal droppings.  It was created by a burrowing animal - either a vole or mole.  My yard is constantly being aerated by burrowing animals.  If you walk around with a stick and probe, you might be surprised by how often you hit a hollow.  That is one way the soil gets disturbed, but where there has been construction, plowing, gardening or any form of earth moving, the chronological order of the soil can move old things higher, but also newer things deeper.  You just can't assume deeper means older, even though it might occasionally be true.

The Florida Museum reported an interesting study.  Here is a summary of that study.

Over the course of 20 years, an international team of scientists collected and carbon-dated more than 7,500 marine fossils from ocean beds around the world.

Scientists used the dataset to determine which of several environmental factors contributes most to time averaging, a phenomenon in which organisms that lived in different time periods are mixed and preserved together in the same fossil bed.

The results indicate that sedimentation is more important than other factors, such as the number of burrowing animals in a given area or the durability of fossils..

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“Our results demonstrate that if we know how quickly sediment accumulates — which can be deduced from the environmental context — we can determine how much time is captured by a given fossil assemblage: The faster individual shells or bones are buried below the sediment surface, the less likely it is that remains from multiple generations of organisms will accumulate and be preserved together,” Nawrot wrote.

So they found the rate of sedimentation to be the most important factor, but that would hold best when the rater of sedimentation is fairly constant.  In shallow waters other forces will completely destroy the regular stratification.  If you get a big storm, for example, that can destroy stratification that occurred by sedimentation over many years.  That would be more true in shallower waters.

The nearshore and low beach areas are being disturbed all the time.  Sedimentation in those area are far from a constant.

The study also ignores differences in fossil characteristics as a factor that separates fossils into different areas.  Just like coins or anything the objects characteristics and the forces acting upon them will determine where they are deposited.  If they are quickly buried they will remain relatively stationary until some event disrupts the stratification.

You might have seen ancient fossils laying on the surface along the Treasure Coast.   They were very  numerous after one big storm.

Here is the link for the Florida Museum study.

Paleontologists spent 20 years carbon-dating thousands of marine fossils, then used them to decode a process fundamental to Earth’s history – Research News

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Surf Chart for the Fort Pierce Area from the Surfguru.com.

So we should expect to see an increasing surf tomorrow.  And the high tides are good and high.

That is the best chance for improved beach conditions that I've seen for a while.  There is a heck of a lot of sand to be moved though, so even if we get some nice new cuts, they will be worth checking, but it is not what I'd hope to see later this Fall.

Good hunting,

TreasureGuide@comcast.net